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1
Unkelbach, Jan, Dávid Papp, Melissa R. Gaddy, Nicolaus Andratschke, Theodore Hong, and Matthias Guckenberger. "Spatiotemporal fractionation schemes for liver stereotactic body radiotherapy." Radiotherapy and Oncology 125, no. 2 (November 2017): 357–64. http://dx.doi.org/10.1016/j.radonc.2017.09.003.
2
Antunac, Katarina, and Lidija Beketić-Orešković. "Breast cancer radiotherapy - changes in fractionation schemes through decades." Libri Oncologici Croatian Journal of Oncology 51, no. 1 (June 27, 2023): 20–24. http://dx.doi.org/10.20471/lo.2023.51.01.03.
Анотація:
Traditionally, as a standard dose fractionation schedule, adjuvant radiotherapy for breast cancer has been performed using prescribed doses of 46–50 Gy divided into daily fractions of 1.8–2 Gy. Overall, radiotherapy treatment took 5 weeks. In the 1990s, schedules using higher daily doses (2.5–3 Gy), a smaller number of fractions (hypofractionation), and a reduced overall prescribed dose started in the context of clinical trials. First results revealed an equivalent cosmetic effect of hypofractionated protocols compared to standard fractionation, and after longer follow-up, hypofractionation was connected with better control of the disease. Hypofractionation started to be considered the new treatment standard. Results of newer clinical trials confirm the efficacy and safety of adjuvant breast cancer radiotherapy lasting 5 working days using daily fractions of 5.2 Gy in certain subgroups of breast cancer patients.
3
Valdagni, Riccardo. "Altered Fractionation in Radiotherapy." Tumori Journal 84, no. 2 (March 1998): 155–59. http://dx.doi.org/10.1177/030089169808400211.
Анотація:
Differences between late-responding (slowly proliferating) normal tissues and early-responding (rapidly proliferating) normal tissues and tumor cells and the event of tumor cell repopulation occurring during treatment have essentially led to the development of altered fractionation schemes. Altered fractionation regimens mainly refer to schedules utilising two or more (small dose) fractions per day for part of or for the entire treatment course. It must be underlined that a true standard or conventional fractionation regimen does not exist: no schedule is universally recognised as the standard of reference to be compared with. However, continental European and U.S. conventional regimens are the considered control arm with which the new experimental regimens have to be compared. For this reason they are generally recognised as the standards. The basic rationale for hyperfractionated or accelerated regimens respectively lies in the possibility (a) to deliver higher total doses reducing late-responding normal tissue damage, (b) to deliver total doses in a reduced overall treatment time to defeat tumor clonogen repopulation. Multiple fractions per day should not be delivered with interfraction intervals smaller than 6 hours. Clinical results of phase I-II and limited but convincing phase III randomised trials suggest that a therapeutic benefit can be achieved with new altered regimens.
4
Kuznetsov, Maxim, and Andrey Kolobov. "Optimization of Dose Fractionation for Radiotherapy of a Solid Tumor with Account of Oxygen Effect and Proliferative Heterogeneity." Mathematics 8, no. 8 (July 22, 2020): 1204. http://dx.doi.org/10.3390/math8081204.
Анотація:
A spatially-distributed continuous mathematical model of solid tumor growth and treatment by fractionated radiotherapy is presented. The model explicitly accounts for three time and space-dependent factors that influence the efficiency of radiotherapy fractionation schemes—tumor cell repopulation, reoxygenation and redistribution of proliferative states. A special algorithm is developed, aimed at finding the fractionation schemes that provide increased tumor cure probability under the constraints of maximum normal tissue damage and maximum fractional dose. The optimization procedure is performed for varied radiosensitivity of tumor cells under the values of model parameters, corresponding to different degrees of tumor malignancy. The resulting optimized schemes consist of two stages. The first stages are aimed to increase the radiosensitivity of the tumor cells, remaining after their end, sparing the caused normal tissue damage. This allows to increase the doses during the second stages and thus take advantage of the obtained increased radiosensitivity. Such method leads to significant expansions in the curative ranges of the values of tumor radiosensitivity parameters. Overall, the results of this study represent the theoretical proof of concept that non-uniform radiotherapy fractionation schemes may be considerably more effective that uniform ones, due to the time and space-dependent effects.
5
Fallai, Carlo, and Patrizia Olmi. "Altered Fractionation Schedules in Radiotherapy of Head and Neck Cancer. A Review." Tumori Journal 78, no. 5 (October 1992): 311–25. http://dx.doi.org/10.1177/030089169207800506.
Анотація:
The authors review the main contributions of international literature to show the current status in clinical trials on unconventional fractionations of the dose in radiotherapy of head and neck cancers. Several clinical (but only a few randomized) trials have been conducted over the last 15 years using hyperfractionated (HF), accelerated (AF) or mixed (HF-AF) schedules. HF schedules have obtained promising results in terms of local control in comparison with conventional fractionation (CF) of the dose. Improvement in survival was also obtained by the random trials of Pinto and Sanchiz, whereas in EORTC trial no. 22791, the improvement in survival rate was only marginal. A significant increase in local control and, less frequently, in survival has been claimed in several studies using HF-AF. Such data still need to be confirmed by a random study, since EORTC trial 22811 showed superimposable results in comparison with CF. Selection of the most suitable cases for altered fractionation schemes is also being studied in ongoing trials of the EORTC (22851) and RTOG (90-03). As regards acute reactions during and after altered fractionation, they are more severe than after CF. Only pure HF with a dose intensity approximately comparable to CF seems to produce similar acute reactions. Several factors have been found to influence the severity of acute mucosal reactions: interfraction interval, overall treatment time, total dose, and field size. As regards late damage, genuine HF schemes seem to cause roughly equivalent late damage in comparison to CF, whereas high-dose intensity schedules have a higher rate of complications. Interfraction interval, overall treatment time, total dose, fraction size and field size can influence the risk of late sequelae. Before altered fractionations can be considered standard therapy, more data are needed, which should be provided by multicentric randomized trials, some of which are already in progress.
6
Joseph, Nuradh, Norman F. Kirkby, Peter J. Hoskin, Catharine M. L. West, Ananya Choudhury, and Roger G. Dale. "Radiobiologically derived biphasic fractionation schemes to overcome the effects of tumour hypoxia." British Journal of Radiology 93, no. 1112 (August 2020): 20190250. http://dx.doi.org/10.1259/bjr.20190250.
Анотація:
Objective: As a fractionated course of radiotherapy proceeds tumour shrinkage leads to resolution of hypoxia and the initiation of accelerated proliferation of radioresistant cancer cells with better repair capacity. We hypothesise that, in tumours with significant hypoxia, improved tumour control could be achieved with biphasic fractionation schedules that either use acceleration after 3–4 weeks of conventional radiotherapy or deliver a higher proportional dose towards the end of a course of treatment. We conducted a modelling study based on the concept of biological effective dose (BED) comparing such novel regimens with conventional fractionation. Methods: The comparator conventional fractionation schedule 70 Gy in 35 fractions delivered over 7 weeks was tested against the following novel regimens, both of which were designed to be isoeffective in terms of late normal tissue toxicity. 40 Gy in 20 fractions over 4 weeks followed by 22.32 Gy in 6 consecutive daily fractions (delayed acceleration) 30.4 Gy in 27 fractions over 4 weeks followed by 40 Gy in 15 fractions over 3 weeks (temporal dose redistribution) The delayed acceleration regimen is exactly identical to that of the comparator schedule over the first 28 days and the BED gains with the novel schedule are achieved during the second phase of treatment when reoxygenation is complete. For the temporal redistribution regimen, it was assumed that the reoxygenation fraction progressively increases during the first 4 weeks of treatment and an iterative approach was used to calculate the final tumour BED for varying hypoxic fractions. Results: Novel fractionation with delayed acceleration or temporal fractionation results in tumour BED gains equivalent to 3.5–8 Gy when delivered in 2 Gy fractions. Conclusion: In hypoxic tumours, novel fractionation strategies result in significantly higher tumour BED in comparison to conventional fractionation. Advances in knowledge: We demonstrate that novel biphasic fractionation regimens could overcome the effects of tumour hypoxia resulting in biological dose escalation.
7
Chalimou, Ioanna, Helena Lind, Georgios C. Sakellaropoulos, Bengt K. Lind, Nikos Papanikolaou, Georgios C. Nikiforidis, and Panayiotis Mavroidis. "Clinical survey for registering treatment decision criteria in advanced non-small-cell lung cancer radiotherapy and determination of the dose–response relationship for 1-year survival." Journal of Radiotherapy in Practice 13, no. 1 (April 22, 2013): 18–28. http://dx.doi.org/10.1017/s1460396912000519.
Анотація:
AbstractPurposeRecent studies have suggested significant variations in radiotherapy schedules used to treat advanced non-small-cell lung cancer (NSCLC), both between different centers in one country as well as between countries. In this study, different treatment methodologies have been explored using management plans proposed by radiation oncologists regarding general questions and theoretical case histories for patients with advanced NSCLC.Materials and methodsThe survey was conducted by sending a questionnaire to 24 radiotherapy centers in Europe. The questionnaire was composed of two sections. The first section concerned reasons for giving radiotherapy, parameters that influence the choice of total dose and fractionation for radiotherapy and kind of equipment used. The second section concerned the management of five theoretical patients (A–E) regarding the selection of the radiotherapy technique and the aim of treatment (radical or palliative). Furthermore, 19 trials comparing different regimens of palliative radiotherapy in patients with NSCLC were reviewed. There were marked differences in the doses of the investigated radiotherapy schemes, the patient characteristics and the assessed outcome measures.Results70% of the responders answered that the most important factors for deciding what dose and fractionation scheme to use were: metastases, performance status (PS) of the patient, lung function and size of the primary tumour. The most common reasons for giving the treatment were symptom relief, prolongation of life and, in some cases, possibly cure. More than 95% of the responders stated that they would give radiotherapy in each of these cases. The total doses proposed where 20 Gy in five fractions or 30 Gy in ten fractions in 2 weeks for the cases A and D. If the previous two schemes were converted to a fractionation scheme delivering 2 Gy per fraction, the equivalent doses would be 23 and 33 Gy, respectively. For the cases B, C and E, the proposed fractionation schemes were 2 Gy daily to 60–68 Gy in 6 weeks or 2 Gy daily to 68 Gy in 7 weeks. For the case E, 20% of the responders suggested Stereotactic Body Radiotherapy (SBRT) giving 21 Gy three times a week with a day apart to 63 Gy. The total dose and number of fractions of radiotherapy are related to the perceived aims and expectations of treatment. Those aiming at extending life would give significantly higher total doses in a larger number of fractions, whereas those aiming at relieving symptoms would give significantly lower total doses. There is evidence for an increase in survival, in patients who are given higher radiotherapy doses, especially in those patients with better PS.ConclusionsThis survey demonstrates a range of treatment strategies for advanced and inoperable NSCLC within Europe. There are a number of factors that influence the perceived aims of treatment and treatment planning. These factors should be taken into account when evaluating the effectiveness of different irradiation techniques, especially in the determination of radiobiological parameters and dose–response relations. The majority of patients should be treated with short courses of palliative radiotherapy, of one or two fractions. The use of high-dose palliative regimens using many fractions or SBRT should be considered for selected patients with good PS.
8
Unkelbach, J., D. Papp, M. Gaddy, N. Andratschke, T. Hong, and M. Guckenberger. "PO-0900: Spatiotemporal fractionation schemes for liver stereotactic body radiotherapy." Radiotherapy and Oncology 127 (April 2018): S479—S480. http://dx.doi.org/10.1016/s0167-8140(18)31210-6.
9
Dudley, Sara, Yushen Qian, Aadel Chaudhuri, Kiran Kumar, Sonya Aggarwal, and Daniel Tandel Chang. "Survival comparison of patients treated with one versus five fraction palliative radiotherapy." Journal of Clinical Oncology 33, no. 29_suppl (October 10, 2015): 200. http://dx.doi.org/10.1200/jco.2015.33.29_suppl.200.
Анотація:
200 Background: Choice of fractionation scheme for palliative radiotherapy has received greater attention in recent years, particularly in the current healthcare environment where issues of cost and quality of life have taken on increasing importance. The ASTRO Choosing Wisely campaign recommends against routine use of extended fractionation schemes ( > 10 fractions) for palliation of bone metastases given equivalent pain relief between 30 Gy in 10 fractions and 8 Gy in 1 fraction, and strong consideration for use of 8 Gy in 1 fraction is urged for patients with a limited prognosis or transportation difficulties. We investigated whether there was a difference in survival between patients treated with an intermediate fractionation scheme (5 fractions) and patients who received single-fraction treatment. Methods: We identified 220 patients who received a total of 264 courses of palliative radiotherapy with either 8 Gy in 1 fraction (n = 91) or 20 Gy in 5 fractions (n = 173). Date of death was obtained from either the patient’s medical record, the Social Security Death Index, or publicly available obituaries. If none of these yielded a date of death, patients were censored at the date of their last clinical encounter. The majority of patients (n = 192) were treated for bone metastases. All primary sites were included, with the three most common histologies being lung, breast and prostate (n = 80, 31 and 16, respectively). Results: Overall, we found no significant survival difference between the two groups. Patients treated with 8 Gy in 1 fraction had a median survival of 146 days, whereas patients treated with 20 Gy in 5 fractions had a median survival of 183 days (p = 0.43). Conclusions: Given no difference in survival between fractionation schemes of 20 Gy in 5 fractions and 8 Gy in 1 fraction, delivery of palliative radiation in a single fraction should be strongly considered. Previous studies have identified a higher re-treatment rate in single-fraction treatments, although closer analysis of this data revealed no difference in absolute pain scores prior to re-treatment. Thus, re-treatment for single-fraction radiotherapy may be due instead to a greater clinical willingness to re-treat as opposed to a greater clinical need.
10
Unkelbach, Jan, Chuan Zeng, and Martijn Engelsman. "Simultaneous optimization of dose distributions and fractionation schemes in particle radiotherapy." Medical Physics 40, no. 9 (August 5, 2013): 091702. http://dx.doi.org/10.1118/1.4816658.
11
Dawson, George Anthony, Ignat Glushko, and Michael Philip Hagan. "A cross-sectional view of radiation fractionation schemes used for painful bone metastases (PBM) cases within the Veterans Health Administration Radiation Oncology Centers." Journal of Clinical Oncology 33, no. 29_suppl (October 10, 2015): 177. http://dx.doi.org/10.1200/jco.2015.33.29_suppl.177.
Анотація:
177 Background: Though the use of single fraction (SF) radiotherapy in the treatment of PBM is an integral component of frontline palliative radiotherapy in Canada and Europe ((Popovic - Radiotherapy and Oncology 111 (2014) 11–17), its use in the United States is only now gaining clinical acceptance. Recently, VHA Radiation Oncologists reported that roughly 76% offer SF to patients with a limited life expectancy (J Palliat Med. 2014 Nov;17(11):1221-5). In this cross-sectional report, we examine the actual dose fractionation schemes used for PBM cases by VHA Radiation Oncologists. Methods: METHOD: An electronic request was sent to 38 of 39 active VHA RO centers asking them to provide the radiation dose fractionation scheme used in the last 10 of their cases of PBM - (International Classification of Diseases (ICD) 198.5 - secondary malignancy of bone and or bone marrow). The study period: 03/01/2015 to 03/16/2015; Response rate: 100%. Data was provided for 382 cases . The survey results were divided by regions, and the 18 Veterans Integrated Service Networks (VISN) w/ VHA RO Centers. Results: RESULTS: According to the 382 cases analyzed, the top 3 fractionation schemes used were: 1st 300cGy x 10 (169); 2nd 800cGy x 1 (69); 3rd 400cGy x5 (63). Overall, SFRT was used in 18% of cases reviewed. There was, however, substantial variation across Veterans Health Administration. While radiation oncology practices in four Veterans Integrated Service Networks (VISN) used SFRT in 50% or more of their reported cases, practices in seven VISNs used SFRT in only 10% or fewer cases. Single fractions and Hypofractionation (3-7) was more common, comprising 45% of the cases. Conclusions: Compared to prior published data, these results suggest that in addition to our previously reported wide availability of hypofractionation for Veterans receiving palliation, actual increased use of Single Fraction and Hypofractionated radiotherapy for PBM is now common within the VHA. VHA RO are using SFRT per the ASTRO 2013 Choosing Wisely Campaign. [Table: see text]
12
Jiménez Cantero, Adriana, Jessica Chávez Nogueda, Fabiola Flores Vázquez, José Pablo Castillo de la Garza, Raymundo Hernández Montes de Oca, and Alejandro Olmos Guzmán. "Hypofractioned radiotherapy versus conventional radiotherapy for the treatment of multiform glioblastoma in adults over 70 years old." Journal of Radiotherapy in Practice 19, no. 2 (July 18, 2019): 193–96. http://dx.doi.org/10.1017/s146039691900044x.
Анотація:
AbstractAim:Multiform glioblastoma (MG) represents 70% of all gliomas, with half of patients older than 65 years with median survival of 12–18 months, hypofractionation seeks to reduce the intensity and duration of treatment without impacting on survival rates. The objective was to determine the global survival and recurrence-free survival of adults over 70 years old with MG treated with hypofractionated radiotherapy and standard scheme. The review of patients older than 70 years treated with radiotherapy from 2013 to 2016 was performed.Results:Twenty-four patients were analysed, with a median follow-up of 239 days, and there is no difference in overall survival 12·3 versus 10·5 months (p = 0·55) and recurrence-free survival 8·3 versus 3·4 months (p = 0·48) between both schemes, conventional versus hypofractioanted, respectively.Conclusion:The results in this study show that hypofractionated scheme could be comparable in overall survival and recurrence-free survival to conventional fractionation, but a longer patients’ trial should be done.
13
MIRESTEAN, Camil Ciprian, Alexandru Dumitru ZARA, Roxana Irina IANCU, and Dragos Petru Teodor IANCU. "Free Educational Android Mobile Application for Radiobiology." Medicina Moderna - Modern Medicine 28, no. 3 (September 1, 2021): 315–19. http://dx.doi.org/10.31689/rmm.2021.28.3.315.
Анотація:
The use of mobile devices and applications dedicated to different medical fields has improved the quality and facilitated medical care, especially in the last 10 years. The number of applications running on the software platforms of smart phones or other smart devices is constantly growing. Radiotherapy also benefits from applications (apps) for TNM staging of cancers, for target volume delineation and toxicity management but also from radiobiological apps for calculating equivalent dose schemes for different dose fractionation regimens. In the context of the increasingly frequent use of altered fractionation schemes, the use of radiobiological models and calculations based on the linear quadratic model (LQ) becomes a necessity. We aim to evaluate free radiobiology apps for the Android software platform. Given the global educational deficit, the lack of experts and the concordance between radiobiology education and the need to use basic clinical notions of modern radiotherapy, the existence of free apps for the Android platform running on older generation processors can transform even an old smart device in a powerful “radiobiology station.” Apps for radiobiology can help the radiation oncologist and medical physicist with responsibilities in radiotherapy treatment planning in the context of accelerated adoption of hypo-fractionation regimens and calculation of the effect of treatment gaps, a topic of interest in the COVID-19 pandemic context. Radiobiology apps can also partially fill the educational gap in radiobiology by arousing the interest of young radiation oncologists to deepen the growing universe of fundamental and clinical radiobiology.
14
MIRESTEAN, Camil Ciprian, Alexandru Dumitru ZARA, Roxana Irina IANCU, and Dragos Petru Teodor IANCU. "Free Educational Android Mobile Application for Radiobiology." Medicina Moderna - Modern Medicine 28, no. 3 (September 1, 2021): 315–19. http://dx.doi.org/10.31689/rmm.2021.28.3.315.
Анотація:
The use of mobile devices and applications dedicated to different medical fields has improved the quality and facilitated medical care, especially in the last 10 years. The number of applications running on the software platforms of smart phones or other smart devices is constantly growing. Radiotherapy also benefits from applications (apps) for TNM staging of cancers, for target volume delineation and toxicity management but also from radiobiological apps for calculating equivalent dose schemes for different dose fractionation regimens. In the context of the increasingly frequent use of altered fractionation schemes, the use of radiobiological models and calculations based on the linear quadratic model (LQ) becomes a necessity. We aim to evaluate free radiobiology apps for the Android software platform. Given the global educational deficit, the lack of experts and the concordance between radiobiology education and the need to use basic clinical notions of modern radiotherapy, the existence of free apps for the Android platform running on older generation processors can transform even an old smart device in a powerful “radiobiology station.” Apps for radiobiology can help the radiation oncologist and medical physicist with responsibilities in radiotherapy treatment planning in the context of accelerated adoption of hypo-fractionation regimens and calculation of the effect of treatment gaps, a topic of interest in the COVID-19 pandemic context. Radiobiology apps can also partially fill the educational gap in radiobiology by arousing the interest of young radiation oncologists to deepen the growing universe of fundamental and clinical radiobiology.
15
Mireștean, Camil Ciprian, Roxana Irina Iancu, and Dragoș Petru Teodor Iancu. "Active Immune Phenotype in Head and Neck Cancer: Reevaluating the Iso-Effect Fractionation Based on the Linear Quadratic (LQ) Model—A Narrative Review." Current Oncology 30, no. 5 (May 8, 2023): 4805–16. http://dx.doi.org/10.3390/curroncol30050362.
Анотація:
Altered fractionation concepts and especially moderate hypo-fractionation are evaluated as alternatives to standard treatment for head and neck squamous cell carcinoma (HNSCC), associated with or not concurrent with or sequential to chemotherapy. The calculation of the iso-equivalent dose regimens has as its starting point the linear quadratic (LQ) formalism traditionally based on the “4Rs” of radiobiology. The higher rates of therapeutic failure after radiotherapy of HNSCC are associated with the heterogeneity of radio-sensibility. The identification of genetic signatures and radio-resistance scores aims to improve the therapeutic ratio of radiotherapy and to conceptualize personalized fractionation schemes. The new data regarding the involvement of the sixth “R” of radiobiology in HNSCC, especially for the HPV-driven subtype, but also for the “immune active” minority of HPV-negative HNSCCs, bring to the fore a multifactorial variation of the α/β ratio. The involvement of the antitumor immune response and the dose/fractionation/volume factors as well as the therapeutic sequence in the case of new multimodal treatments including immune checkpoint inhibitors (ICIs) could be included as an additional term in the quadratic linear formalism especially for hypo-fractionation regimens. This term should take into account the dual immunomodulatory effect (immunosuppressant and stimulator of antitumor immunity) of radiotherapy, which varies from case to case and can bring benefit or a detrimental effect.
16
Liew, Hans, Stewart Mein, Thomas Tessonnier, Amir Abdollahi, Jürgen Debus, Ivana Dokic, and Andrea Mairani. "Do We Preserve Tumor Control Probability (TCP) in FLASH Radiotherapy? A Model-Based Analysis." International Journal of Molecular Sciences 24, no. 6 (March 7, 2023): 5118. http://dx.doi.org/10.3390/ijms24065118.
Анотація:
Reports of concurrent sparing of normal tissue and iso-effective treatment of tumors at ultra-high dose-rates (uHDR) have fueled the growing field of FLASH radiotherapy. However, iso-effectiveness in tumors is often deduced from the absence of a significant difference in their growth kinetics. In a model-based analysis, we investigate the meaningfulness of these indications for the clinical treatment outcome. The predictions of a previously benchmarked model of uHDR sparing in the “UNIfied and VERSatile bio response Engine” (UNIVERSE) are combined with existing models of tumor volume kinetics as well as tumor control probability (TCP) and compared to experimental data. The potential TCP of FLASH radiotherapy is investigated by varying the assumed dose-rate, fractionation schemes and oxygen concentration in the target. The developed framework describes the reported tumor growth kinetics appropriately, indicating that sparing effects could be present in the tumor but might be too small to be detected with the number of animals used. The TCP predictions show the possibility of substantial loss of treatment efficacy for FLASH radiotherapy depending on several variables, including the fractionation scheme, oxygen level, and DNA repair kinetics. The possible loss of TCP should be seriously considered when assessing the clinical viability of FLASH treatments.
17
Singh, Gaganpreet, Rose Kamal, Deepak Thaper, Arun Singh Oinam, Bhumika Handa, Vivek Kumar, and Narendra Kumar. "Voxel based evaluation of sequential radiotherapy treatment plans with different dose fractionation schemes." British Journal of Radiology 93, no. 1112 (August 2020): 20200197. http://dx.doi.org/10.1259/bjr.20200197.
Анотація:
Objective: This study presents a methodology for voxel-based evaluation of two phase sequential radiotherapy treatment plans having conventional dose scheme in the first phase and subsequent hypofractionation dose scheme in the second phase based upon different priority [planning target volume (PTV), clinical target volume (CTV) and organs at risk (OAR)] of display modes. Methods: A case of carcinoma prostate was selected for demonstration. Varian Eclipse treatment planning system (TPS) was used for contouring and planning. In the first phase, a dose of 52 Gy in 26 fractions to the PTV and in the second phase, a dose of 19.5 Gy in 3 fractions to the PTV Boost was planned on the same CT data set. Both the plans (Phase 1 and Phase 2) were exported and processed using “Voxel-based radiobiology display (VRb) tool”. Plan Sum for Biologically effective dose (BED)-Cube and equivalent dose of 2Gy (EQD2)-Cube was reconstructed using a combination of linear quadratic (LQ) and linear quadratic-linear (LQ-L) radiobiological models. Tumor control probability (TCP) and normal tissue complication probability (NTCP) for different target volumes and organs were also calculated using EQD2-volume histograms of the Plan Sum. Results: An in-house graphical user interface (GUI) is developed to present the qualitative and quantitative evaluation of the multiphase treatment plans with different display modes and dose regimens. The voxel based TCP obtained for the combined target volume was 90.56%. NTCP for the bladder and rectum was calculated from the Plan Sum histograms and found to be 0.33% and ~0.0% respectively. Conclusion: The proposed methodology using the VRb tool offers superior plan evaluation for multiphase sequential radiotherapy treatment plans over the existing methods. Advances in knowledge: PTV, CTV and OAR priority based display modes in VRb tool offers better understanding of radiobiological evaluation of sequential radiotherapy treatment plans.
18
Qureshy, Sarah A., Marshall A. Diven, Xiaoyue Ma, Ariel E. Marciscano, Jim C. Hu, Tim D. McClure, Christopher Barbieri, and Himanshu Nagar. "Differential Use of Radiotherapy Fractionation Regimens in Prostate Cancer." JAMA Network Open 6, no. 10 (October 10, 2023): e2337165. http://dx.doi.org/10.1001/jamanetworkopen.2023.37165.
Анотація:
ImportanceTechnical advances in treatment of prostate cancer and a better understanding of prostate cancer biology have allowed for hypofractionated treatment courses using a higher dose per fraction. Use of ultrahypofractionated stereotactic body radiotherapy (SBRT) has also been characterized.ObjectiveTo characterize US national trends of different RT fractionation schemes across risk groups of prostate cancer.Design, Setting, and ParticipantsThis retrospective cohort study used data collected by the National Cancer Database (NCDB) to characterize the fractionation regimens used for 302 035 patients diagnosed as having prostate cancer from January 1, 2004, to December 31, 2020, who underwent definitive RT. The analysis was performed between February 1 and April 30, 2023.ExposureStereotactic body RT or ultrahypofractionation, defined as 5 or fewer fractions of external beam RT (EBRT), moderate hypofractionation, defined as 20 to 28 fractions of EBRT, or conventional fractionation, defined as all remaining EBRT fractionation schemes.Main Outcomes and MeasuresTemporal trends and clinical and sociodemographic factors associated with SBRT, moderate hypofractionation, and conventional fractionation use.ResultsA total of 302 035 men receiving EBRT for localized prostate cancer between 2004 and 2020 were identified (40.1% aged 60-69 years). Black patients comprised 17.6% of this cohort; White patients, 77.9%; and other races and ethnicities, 4.5%. Patients with low-risk disease comprised 17.5% of the cohort; favorable intermediate-risk disease, 23.5%; unfavorable intermediate-risk disease, 23.9%; and high-risk disease, 35.1%. Treatment consisted of conventional fractionation for 81.2%, moderate hypofractionation for 12.9%, and SBRT for 6.0%. The rate of increase over time in patients receiving SBRT compared with conventional fractionation was higher (adjusted odds ratio [AOR] for 2005 vs 2004, 3.18 [95% CI, 2.04-4.94; P < .001]; AOR for 2020 vs 2004, 264.69 [95% CI, 179.33-390.68; P < .001]) than the rate of increase in patients receiving moderate hypofractionation compared with conventional fractionation (AOR for 2005 vs 2004, 1.05 [95% CI, 0.98-1.12; P = .19]; AOR for 2020 vs 2004, 4.41 [95% CI, 4.15-4.69; P < .001]). Compared with White patients, Black patients were less likely to receive SBRT compared with conventional fractionation or moderate hypofractionation (AOR for conventional fractionation, 0.84 [95% CI, 0.80-0.89; P < .001]; AOR for moderate hypofractionation, 0.77 [95% CI, 0.72-0.81; P < .001]). Compared with 2019, patients treated with all fractionation regimens declined in 2020 by 24.4%.Conclusions and RelevanceIn this hospital-based cohort study of patients with prostate cancer treated with definitive EBRT, use of moderate hypofractionation and SBRT regimens for definitive prostate cancer treatment has increased from 2004 to 2020. Despite this increasing trend, findings suggest potential health care disparities for Black patients receiving EBRT for localized prostate cancer. The number of patients treated with EBRT in the year 2020 decreased, coinciding with official onset of the COVID-19 pandemic in March 2020.
19
Ma, Ting Martin, Oscar Lilleby, Wolfgang A. Lilleby, and Amar U. Kishan. "Ablative Radiotherapy in Prostate Cancer: Stereotactic Body Radiotherapy and High Dose Rate Brachytherapy." Cancers 12, no. 12 (December 2, 2020): 3606. http://dx.doi.org/10.3390/cancers12123606.
Анотація:
Prostate cancer (PCa) is the most common noncutaneous solid organ malignancy among men worldwide. Radiation therapy is a standard of care treatment option that has historically been delivered in the form of small daily doses of radiation over the span of multiple weeks. PCa appears to have a unique sensitivity to higher doses of radiation per fraction, rendering it susceptible to abbreviated forms of treatment. Stereotactic body radiation therapy (SBRT) and high-dose-rate brachytherapy (HDRBT) are both modern radiation modalities that allow the precise delivery of ablative doses of radiation to the prostate while maximally sparing sensitive surrounding normal structures. In this review, we highlight the evidence regarding the radiobiology, oncological outcomes, toxicity and dose/fractionation schemes of SBRT and HDRBT monotherapy in men with low-and intermediate-risk PCa.
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Woody, Neil M., Gregory M. M. Videtic, Kevin L. Stephans, Toufik Djemil, Yongbok Kim, and Ping Xia. "Predicting Chest Wall Pain From Lung Stereotactic Body Radiotherapy for Different Fractionation Schemes." International Journal of Radiation Oncology*Biology*Physics 83, no. 1 (May 2012): 427–34. http://dx.doi.org/10.1016/j.ijrobp.2011.06.1971.
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Horiot, J. C., P. Bontemps, A. C. Begg, R. Le Fur, W. van den Bogaert, M. Bolla, T. Nguyen, et al. "New radiotherapy fractionation schemes in head and neck cancers. The EORTC trials: A benchmark." European Journal of Cancer 33 (September 1997): S133. http://dx.doi.org/10.1016/s0959-8049(97)85138-6.
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Mayer, Árpád, and Zsuzsa Póti. "Novel irradiation techniques in the treatment of solid tumours. Radiotherapy of metastases." Orvosi Hetilap 155, no. 8 (February 2014): 283–90. http://dx.doi.org/10.1556/oh.2014.29832.
Анотація:
Novel developments in percutaneous radiotherapy, such as positron emission tomography/computed tomography, adaptive radiation planning, intensity modulation radiotherapy and intensity modulated arc therapy (RapidArc), as well as the newer generation of image control (cone-beam computed tomography) and image guided radiotherapy ensure increased dosages of planning target volume and clinical target volume of solid tumours without damaging surrounding tissues and providing maximal protection. By raising the dosages of planned target volume and clinical target volume, these novel technical developments have created new indications in the treatment of solid tumours. With the aid of the cone-beam computed tomography and image guided radiotherapy the organ metastasis (lung, liver, spinal cord) and the primary tumour can be treated safety and effectively. Hypofractionation, dose escalation and the use of stereotactic devices can probably decrease radiation damage. The authors review the most common forms of evidence-based fractionation schemes used in irradiation therapy. Orv. Hetil., 2014, 155(8), 283–290.
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Nikzad, Safoora, Bijan Hashemi, Golshan Mahmoudi, and Milad Baradaran-Ghahfarokhi. "Estimation of cell response in fractionation radiotherapy using different methods derived from linear quadratic model." Radiology and Oncology 49, no. 4 (December 1, 2015): 347–56. http://dx.doi.org/10.1515/raon-2015-0040.
Анотація:
Abstract Background. The aim of this study was to use various theoretical methods derived from the Linear Quadratic (LQ) model to calculate the effects of number of subfractions, time intervals between subfractions, dose per subfraction, and overall fraction time on the cells’ survival. Comparison of the results with experimental outcomes of melanoma and breast adenocarcinoma cells was also performed. Finally, the best matched method with experimental outcomes is introduced as the most accurate method in predicting the cell response. Materials and methods. The most widely used theoretical methods in the literature, presented by Keall et al., Brenner, and Mu et al., were used to calculate the cells’ survival following radiotherapy with different treatment schemes. The overall treatment times were ranged from 15 to 240 minutes. To investigate the effects of number of subfractions and dose per subfraction, the cells’ survival after different treatment delivery scenarios were calculated through fixed overall treatment times of 30, 60 and 240 minutes. The experimental tests were done for dose of 4 Gy. The results were compared with those of the theoretical outcomes. Results. The most affective parameter on the cells’ survival was the overall treatment time. However, the number of subfractions per fractions was another effecting parameter in the theoretical models. This parameter showed no significant effect on the cells’ survival in experimental schemes. The variations in number of subfractions per each fraction showed different results on the cells’ survival, calculated by Keall et al. and Brenner methods (P<0.05). Conclusions. Mu et al. method can predict the cells’ survival following fractionation radiotherapy more accurately than the other models. Using Mu et al. method, as an accurate and simple method to predict the cell response after fractionation radiotherapy, is suggested for clinical applications.
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Kamel, Randa, Tinghua Zhang, Suzanne Comino, and Kristopher Dennis. "A 15-Year Single-Institution Retrospective Study of Primary Pancreatic Cancer Treated with Non-Ablative Palliative Radiotherapy." Cancers 16, no. 5 (February 22, 2024): 881. http://dx.doi.org/10.3390/cancers16050881.
Анотація:
We studied the use of palliative radiotherapy (RT) among patients with primary, non-curable, locally advanced pancreatic cancer. In this subset of patients, with very poor survival, various palliative RT dose fractionation schemes are used; but, in the absence of a guideline, practice patterns vary, and dose choice is mainly based on the physician’s intuition. We divided the patients into three groups, according to the dose fractionation schedules received: low (A), intermediate (B), and high (C) dose groups, to study the potential differences in outcome between the different dose prescriptions. Cohort: n = 184. Median age: 69 years. Male: n = 105 (57%), female: n = 79 (43%). Stage IV: n = 117 (64%). T4: n = 127 (69%). Tumor location: head: n = 109 (59%), body: n = 37 (20%), tail: n = 25 (14%), neck: n = 11 (6%), and uncinate: n = 2 (1%). Prior systemic therapy: n = 66 (36%). Most common dose fractionations received: 20 Gy in five fractions n = 67 (36%), 30 Gy in 10 fractions n = 49 (27%), and 8 Gy in one fraction n = 23 (13%). Group A: n = 33 (18%), median overall survival (OS) 19 days (95% CI 4–33). Group B: n = 84 (46%), median OS 52 days (95% CI 43–60). Group C: n = 67 (36%), median OS 126 days (95% CI 77–174). Median days to in-field progression: Group A 59 days (range 7–109), Group B 96 days (range 19–173), and Group C 97 days (range 13–475). To our knowledge, this is the largest reported retrospective cohort of patients receiving non-ablative palliative RT to treat their primary pancreatic tumors. Most patients had metastatic disease, T4 tumors of the pancreatic head and had not received prior systemic therapy. A significant survival benefit was seen favoring the high dose/longer RT fractionation group, presumably due to appropriate patient selection rather than an RT effect. Despite the relatively short median overall survival, one fifth of the patients were found to experience an in-field progression following RT.
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Shirvani, Shervin M., Calvin J. Huntzinger, Thorsten Melcher, Peter D. Olcott, Yevgen Voronenko, Judy Bartlett-Roberto, and Samuel Mazin. "Biology-guided radiotherapy: redefining the role of radiotherapy in metastatic cancer." British Journal of Radiology 94, no. 1117 (January 1, 2021): 20200873. http://dx.doi.org/10.1259/bjr.20200873.
Анотація:
The emerging biological understanding of metastatic cancer and proof-of-concept clinical trials suggest that debulking all gross disease holds great promise for improving patient outcomes. However, ablation of multiple targets with conventional external beam radiotherapy systems is burdensome, which limits investigation and utilization of complete metastatic ablation in the majority of patients with advanced disease. To overcome this logistical hurdle, technical innovation is necessary. Biology-guided radiotherapy (BgRT) is a new external beam radiotherapy delivery modality combining positron emission tomography-computed tomography (PET-CT) with a 6 MV linear accelerator. The key innovation is continuous response of the linear accelerator to outgoing tumor PET emissions with beamlets of radiotherapy at subsecond latency. This allows the deposited dose to track tumors in real time. Multiple new hardware and algorithmic advances further facilitate this low-latency feedback process. By transforming tumors into their own fiducials after intravenous injection of a radiotracer, BgRT has the potential to enable complete metastatic ablation in a manner efficient for a single patient and scalable to entire populations with metastatic disease. Future trends may further enhance the utility of BgRT in the clinic as this technology dovetails with other innovations in radiotherapy, including novel dose painting and fractionation schemes, radiomics, and new radiotracers.
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Ibrahim, Hassan, and Usman Bello. "Dose Fractionation Schemes for Palliative External Beam Radiotherapy on Painful Bone Metastasis from Breast Cancer." Borno Medical Journal 17, no. 1 (June 30, 2020): 1–9. http://dx.doi.org/10.31173/bomj.bomj_135_17.
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Hamilton, Julie, Geoff Higgins, and Eric Bernhard. "Conventional radiotherapy or hypofractionation? A study of molecular changes resulting from different radiation fractionation schemes." Cancer Biology & Therapy 8, no. 9 (May 2009): 774–76. http://dx.doi.org/10.4161/cbt.8.9.8341.
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Fallai, Carlo, Patrizia Olmi, and Enrico Cellai. "Advanced carcinomas of the oropharynx treated with radiotherapy—A comparison of three different fractionation schemes." American Journal of Otolaryngology 14, no. 1 (January 1993): 31–37. http://dx.doi.org/10.1016/0196-0709(93)90007-t.
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Borm, Kai J., Johanne Kleine Vennekate, Jan Vagedes, Mohammad O. A. Islam, Marciana N. Duma, Maximilian Loos, Stephanie E. Combs, et al. "A Comprehensive Prospective Comparison of Acute Skin Toxicity after Hypofractionated and Normofractionated Radiation Therapy in Breast Cancer." Cancers 13, no. 22 (November 20, 2021): 5826. http://dx.doi.org/10.3390/cancers13225826.
Анотація:
The current study aims to determine whether hypofractionated radiotherapy (HF) leads to lower rates of acute radiodermatitis compared to conventional normofractionated radiotherapy (CF). A total of 166 patients with invasive breast cancer or DCIS were included in a prospective cohort study. Evaluation of acute radiodermatitis was obtained before radiotherapy, at the end of the treatment (T1), and 6 weeks after the treatment (T2) using CTCAE (v5.0) scores, the Skindex-16 questionnaire, and ultrasound measurement of the skin. CTCAE and Skindex-16 scores in the CF-group were significantly higher compared to the HF group indicating more pronounced side effects at the end of the treatment (CTCAE: CF-RT 1.0 (IQR: 0.0) vs. HF-RT 0.0 (0.25); p = 0.03; Skindex-16: CF: 20.8 (IQR: 25.8); HF: 8.3 (27.1); p = 0.04). At 6 weeks after the treatment, no significant differences between the two fractionation schemes were observed. Ultrasound based assessment showed that the skin thickness in the treated breast was higher compared to the healthy breast at all time-points. However, no significant difference between HF and CF was seen either at T1 or T2. The current study complements and confirms pre-existing evidence that HF leads to a lower degree of acute radiodermatitis and better patient reported outcome compared to CF at the end of treatment. This should be considered whenever fractionation of adjuvant breast cancer treatment is being discussed.
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Ferini, Gianluca, Antonella Tripoli, Vincenza Umina, Giuseppina Rita Borzì, Valentina Anna Marchese, Salvatore Ivan Illari, Alberto Cacciola, Sara Lillo, Silvana Parisi, and Vito Valenti. "Radiation Proctitis: The Potential Role of Hyaluronic Acid in the Prevention and Restoration of Any Damage to the Rectal Mucosa among Prostate Cancer Patients Submitted to Curative External Beam Radiotherapy." Gastroenterology Insights 12, no. 4 (December 10, 2021): 446–55. http://dx.doi.org/10.3390/gastroent12040043.
Анотація:
Aim: To evaluate if hyaluronic acid reduces proctitis episodes with respect to corticosteroids in prostate cancer patients submitted to radical or adjuvant radiotherapy. Methods: A consecutive series of eligible patients received hyaluronic acid enemas as supportive care (experimental group, from January 2013 to June 2015). A historical group (control group), treated from October 2011 to December 2012, received beclomethasone dipropionate suppositories. We registered each patient’s data regarding acute and chronic proctitis. All patients were treated with static-intensity-modulated radiotherapy coupled to a daily set-up verification with orthogonal anterior–posterior/lateral X-ray pairs. Results: A total of 269 patients, 175 in the experimental group and 94 in the control group, was evaluated; 2 Gy/day (up to a total median dose of 80 Gy) and 2.7 Gy/day (up to a total median dose of 67.5 Gy) fractionation schemes were used for 216 and 53 patients, respectively. All patients had a good tolerance to radiotherapy, reporting no G3 or greater proctitis. No significant difference was reported concerning the total rate of proctitis between the two groups but only with respect to its grade: a higher G2 rate within the control group. There was no correlation between daily dose fractionation and toxicity grade. Conclusions: Hyaluronic acid enemas might be effective in reducing the severity of radiation proctitis.
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Falkson, C. B., E. T. Vella, E. Yu, M. El-Mallah, R. Mackenzie, P. M. Ellis, and Y. C. Ung. "Guideline for radiotherapy with curative intent in patients with early stage, medically inoperable, non-small cell lung cancer." Current Oncology 24, no. 1 (February 28, 2017): 44. http://dx.doi.org/10.3747/co.24.3358.
Анотація:
Objectives For this guideline, we investigated the effectiveness of radiotherapy with curative intent in medically inoperable patients with early-stage non-small-cell lung cancer (nsclc).Methods The guideline was developed by Cancer Care Ontario’s Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of mainly retrospective studies, expert consensus, and formal internal and external reviews.RecommendationsStereotactic body radiation therapy (sbrt) with curative intent is an option that should be considered for patients with early-stage, node-negative, medically inoperable nsclc.Qualifying StatementsBecause of the high dose per fraction, the planning process and treatment delivery for sbrt require the use of advanced technology to maintain an appropriate level of safety. Consistent patient positioning and 4-dimensional analysis of tumour and critical structure motion during simulation and treatment delivery are essential.Preliminary results for proton-beam therapy have been promising, but the technique requires further clinical study.Recommended fractionation schemes for sbrt should result in a biologically effective dose of 100 or greater by the linear quadric model, choosing an α/β value of 10 [bed10(LQ) ≥ 100]. Qualifying StatementsBecause of the increased risk of treatment-related adverse events associated with centrally located tumours, consideration of tumour size and proximity to critical central structures is required when determining the dose and fractionation.Examples of dose–fractionation schemes used in the included studies have been provided.Based on the current evidence and the opinion of the authors, radiation doses at bed10(LQ) greater than 146 might significantly increase toxicity and should be avoided.Determination of the radiation bed by the linear quadratic model has limitations for the extreme hypofractionated schemes used in sbrt.
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Vetrugno, Irene, Irma Telarovic, Nathan Torelli, Jan Unkelbach, and Martin Pruschy. "Abstract 2879: Spatiotemporal fractionation: An innovative concept of fractionated radiotherapy." Cancer Research 84, no. 6_Supplement (March 22, 2024): 2879. http://dx.doi.org/10.1158/1538-7445.am2024-2879.
Анотація:
Abstract Impressive outcomes in therapeutic radiation oncology have been achieved in the past decade through the development of advanced computer technology and imaging methods, such as intensity modulated radiotherapy. Ideally, radiotherapy treatment delivers a high dose to the tumor while sparing the surrounding healthy tissues and organs at risk from radiation damage. Spatiotemporal Fractionated Radiotherapy has emerged as an innovative technique that delivers different dose distributions to different parts of the tumor in order to achieve high doses to the target while ensuring a low dose-bath in the surrounding normal tissue. Spatiotemporally fractionated regimens showed in silico up to 10 - 15% sparing of normal tissue from radiation damage, while ensuring isoeffective tumor control compared to conventionally fractionated regimens. However, prior to advancing spatiotemporal fractionation to the clinical level, it is important to probe the validity of the main assumption of spatiotemporal fractionation derived from the Biologically Effective Dose (BED) model: two different fractionation schemes that implement a high and a low dose will lead to equivalent clinical effects, regardless of dose-treatment sequence. A tumor growth delay study was performed in a subcutaneous immunocompetent murine tumor model (MC38-tumor cell derived) receiving two different fractionation regimens. Particularly, tumors belonging to the two treatment groups received the same dose combination - a high (12 Gy) and a low (6 Gy) dose fraction separated by 72 hours - with the doses delivered in opposite order in the two treatment groups. The same experimental outline was performed in a subcutaneous immunodeficient murine tumor model derived from the same tumor cells. Tumors were also characterized by immunophenotyping analysis seven days after first irradiation. Even though the two regimens deliver the same physical dose to the tumor - and would be considered equivalent according to the BED model - different tumor growth delays were observed in a time window of 30 days after first irradiation depending on the treatment group. Such differences were observed in the immunocompetent model but not in the immunodeficient model. The immunophenotyping results showed immunostimulatory vs immunosuppressive phenotypes of the tumor microenvironment depending on the order of the treatment doses. An additional tumor growth delay study including immune checkpoint inhibitors confirmed the fundamental role of the immune system with the differential efficacy outcomes of the two regimens. Overall, these intriguing results suggest that a differential radiotherapy-induced immune response to different doses of ionizing radiation plays an important role in the treatment outcome and asks for re-evaluation of the BED model taking scheduling-dependent parameters into consideration. Citation Format: Irene Vetrugno, Irma Telarovic, Nathan Torelli, Jan Unkelbach, Martin Pruschy. Spatiotemporal fractionation: An innovative concept of fractionated radiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2879.
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Moore, Assaf, Robert Benjamin Den, Noa Gordon, Michal Sarfaty, Yulia Kundel, Baruch Brenner, and Daniel A. Goldstein. "The financial impact of fractionation scheme and treatment planning method for rectal cancer in the United States." Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): 6518. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.6518.
Анотація:
6518 Background: Preoperative long-course chemoradiotherapy (CRT) and short-course radiotherapy (SCR) for locally advanced rectal cancer (LARC) were found to have equivalent outcomes in three randomized trials. SCR may have lower acute toxicity and the down-staging following CRT is more well-established. At present, SCR is frequently used in Europe but has not been widely adopted in the United States (US). It is standard to deliver radiotherapy by 3D planning, while the use of Intensity-modulated radiotherapy (IMRT) is controversial. In recent years there has been an increasing focus on understanding the cost and value of cancer care. In this study we aimed to assess the economic impact of fractionation scheme and treatment planning method for payers in the US. Methods: We performed a population-based analysis of the total cost of radiotherapy for LARC in the US annually. The national annual target population of patients was calculated using the Surveillance, Epidemiology, and End Results (SEER) database. Treatment costs for various fractionation schemes were based on billing codes and 2018 pricing by Medicare's Hospital Outpatient Prospective Payment System (OPPS). The cost of chemotherapy was based on the Payment Allowance Limits for Medicare Part B Drugs by Centers for Medicare and Medicaid Services (CMS). Results: We estimate that 12,945 patients with LARC are treated with radiotherapy annually in the US. The cost of CRT with 3-D or IMRT is US$ 15,881.76 and US$ 23,744.82 per patient, respectively. With 3-D SCR the cost is US$ 5,457 per patient. The use of SCR would lead to 64-77% annual savings of US$ 125,701,387 - US$ 236,727,934 in the US compared with 3-D and IMRT based CRT, respectively. IMRT based planning increases the total cost of CRT by 49% and if adopted widely would lead to an excess cost of US$ 101,787,312 annually. Conclusions: SCR may have the potential to save in the region of US$ 0.12-0.23 billion annually in the US, likely without impacting outcomes. Lack of evidence showing benefit with costly IMRT should limit its use to clinical trials. SCR may also lead to lower personal financial toxicity. It would be reasonable for public and private payers to consider which type of radiation is most suited to reimbursement.
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Stephans, K., N. M. Woody, G. M. M. Videtic, T. Djemil, and P. Xia. "Chest Wall Toxicity from Lung Stereotactic Body Radiotherapy (SBRT): A Dosimetric Analysis using Several Fractionation Schemes." International Journal of Radiation Oncology*Biology*Physics 78, no. 3 (November 2010): S506. http://dx.doi.org/10.1016/j.ijrobp.2010.07.1182.
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Brizel, David M., and Ramon Esclamado. "Concurrent Chemoradiotherapy for Locally Advanced, Nonmetastatic, Squamous Carcinoma of the Head and Neck: Consensus, Controversy, and Conundrum." Journal of Clinical Oncology 24, no. 17 (June 10, 2006): 2612–17. http://dx.doi.org/10.1200/jco.2005.05.2829.
Анотація:
Radiotherapy and concurrent chemotherapy (CRT) is superior to radiotherapy alone for the treatment of locally advanced, nonmetastatic squamous carcinoma of the head and neck (HNC). Three issues affect the use of CRT as primary treatment for advanced HNC. The first issue is the definition of advanced stage and the initial therapeutic choice of surgery or CRT and the role of post-CRT neck dissection. Function preservation considerations should guide the choice between surgery and CRT for patients with resectable disease. Fluorodeoxyglucose–positron emission tomography scanning may identify patients who require adjuvant neck dissection. The second issue is optimization of radiotherapy and chemotherapy schedules. Ideally, concurrent chemotherapy should be incorporated into radiotherapy (RT) regimens that would constitute optimal therapy were RT to be administered as single-modality treatment. Modified fractionation schemes constitute optimal single-modality RT. Platinum schedules other than bolus dosing every 3 to 4 weeks are effective and may be less toxic. The third issue is integration of biologically targeted therapy into CRT treatment programs. Epidermal growth factor receptor blockade enhances the effectiveness of RT alone. Its role and that of angiogenic blockade in CRT are under investigation.
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DeAngelis, Lisa M., Lynda R. Mandell, H. Tzvi Thaler, David W. Kimmel, Joseph H. Galicich, Zvi Fuks, and Jerome B. Posner. "The Role of Postoperative Radiotherapy after Resection of Single Brain Metastases." Neurosurgery 24, no. 6 (June 1, 1989): 798–805. http://dx.doi.org/10.1227/00006123-198906000-00002.
Анотація:
ABSTRACT To assess the value of whole brain radiotherapy (WBRT) after complete resection of a single brain metastasis we reviewed the records of 98 patients who had elective craniotomy between 1978 and 1985. Seventy-nine patients received postoperative WBRT (Group A) and 19 patients no radiotherapy (RT) (Group B). Neurological relapse was designated as local (i.e., at the site of the original metastasis) or distant (i.e., elsewhere in the brain). Postoperative WBRT significantly prolonged the time to any neurological relapse (P = 0.034) with a 1-year recurrence rate of 22% in Group A and 46% in Group B patients; however, it did not specifically control either local or distant cerebral recurrence. Recurrence of metastatic brain disease was not affected by location of the original lesion; however, meningeal relapse occurred in 38% of cerebellar lesions, but only in 4.7% of supratentorial metastases (P = 0.003). The total radiation dose or fractionation scheme of RT did not affect survival nor time to neurological relapse. The median survival was 20.6 and 14.4 months for Groups A and B, respectively (not statistically different). Forty-eight percent of Group A and 47% of Group B patients survived for 1 year or longer; however, 11% of patients who had received RT and survived 1 year developed severe radiation-induced dementia. All patients with radiation-related cerebral damage received hypo-fractionated RT with high daily fractions as commonly designed for rapid palliation of macroscopic brain metastases. Thus, postoperative WBRT may be an important adjunct to complete resection of a single brain metastasis, particularly in patients with limited or no systemic disease who have the potential for long-term survival or even cure, but it carries a substantial risk of late neurological toxicity when hypofractionated RT schedules are used. For these good-risk patients, postoperative WBRT should be administered by standard fractionation schemes of 180 to 200 cGy/day to a total of 4000 to 4500 cGy, or hyperfractionation, which provides even lower doses/fraction to minimize potential neurotoxicity while delivering a maximally efficacious total dose, should be considered.
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Antipas, V. P., N. K. Uzunoglu, and G. S. Stamatakos. "A Patient-specific in vivo Tumor and Normal Tissue Model for Prediction of the Response to Radiotherapy." Methods of Information in Medicine 46, no. 03 (2007): 367–75. http://dx.doi.org/10.1160/me0312.
Анотація:
Summary Objectives: Integration of multiscale experimental cancer biology through the development of computer simulation models seems to be a necessary step towards the better understanding of cancer and patient-individualized treatment optimization. The integration of a four-dimensional patient-specific model of in vivo tumor response to radiotherapy developed by our group with a model of slowly responding normal tissue based on W. Duechting’s approach is presented in this paper. The case of glioblastoma multiforme and its surrounding neural tissue is addressed as a modeling paradigm. Methods: A cubic discretizing mesh is superimposed upon the anatomic region of interest as is reconstructed from pertinent imaging (e.g. MRI) data. On each geometrical cell of the mesh the most crucial biological “laws” e.g. metabolism, cell cycling, tumor geometry changes, cell kill following irradiation etc. are applied. Slowly responding normal neural tissue is modeled by a functional compartment containing indivisible cells and a divisible compartment containing glial cells. Results: The model code has been executed for a simulated period normally covering the radiotherapy course duration and extending a few days after its completion. The following schemes have been simulated: standard fractionation, hyperfractionation, accelerated fractionation, accelerated hyperfractionation and hypofractionation. The predictions are in agreement with the outcome of the RTOG 83-02 phase I/II trial, the retrospective study conducted by Sugawara et al. and the theoretical predictions of Duechting et al. Conclusions: The presented model, although oversimplified, may serve as a basis for a refined simulation of the biological mechanisms involved in tumor and normal tissue response to radiotherapy.
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Kraszkiewicz, M., A. Napieralska, J. Wydmański, R. Suwiński, and W. Majewski. "Evaluation of Efficacy and Tolerance of Radical Radiotherapy and Radiochemotherapy in Treatment of Locally Advanced, Unresectable Rectal Cancer." Technology in Cancer Research & Treatment 21 (January 2022): 153303382210860. http://dx.doi.org/10.1177/15330338221086085.
Анотація:
Background: A retrospective evaluation of tolerance and efficacy of two schemes of neoadjuvant treatment in patients (pts) with unresectable rectal cancer: radiochemotherapy (CRT) and radiotherapy (RT), including conventional and accelerated hyperfractionation. Material and Method: A total of 145 consecutive pts with unresectable, locally advanced rectal cancer. The schemes used are RT in 73 (50%) or CRT in 72 (50%). In CRT, 54 Gy in 1.8 Gy fractions was given with chemotherapy, In the RT group, conventional fractionation (CFRT) and hyperfractionated accelerated radiotherapy (HART). HART was introduced at first as an alternative to CFRT, after radiobiological studies suggesting a therapeutic gain of hyperfractionation in other cancers, and second to administer relatively high dose needed in unresectable cancer, which is not feasible in hypofractionation because of critical organs sensitivity to high fraction doses (fd). HART was an alternative option in pts with medical contraindications to chemotherapy and to shorten overall treatment time with greater radiobiological effectiveness than CFRT. Results: Objective response (OR) in the RT and CRT group was 60% versus 75%. Resection rate (RR) in RT and CRT: 37% versus 65%. Tumor mobility and laparotomy-based unresectability were significant factors for OR. Performance status (PS), tumor mobility, and neoadjuvant treatment method were significant for RR.
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Rodrigues, M., P. Teles, R. Pirraco, D. Oliveira, and P. Costa. "Evaluation of fractionation schemes in breast cancer radiotherapy and dosimetric study of the main organs at risk." Physica Medica 92 (December 2021): S185. http://dx.doi.org/10.1016/s1120-1797(22)00396-9.
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Graham, PH, WJ Morris, and P. Pickles. "Four-week arc radiotherapy for B2-Cprostate cancer: The need for prospective evaluation of short fractionation schemes." Australasian Radiology 41, no. 3 (August 1997): 266–69. http://dx.doi.org/10.1111/j.1440-1673.1997.tb00671.x.
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Machado, Bruno da Silva, Gustavo Benitez Alvarez, and Diomar Cesar Lobão. "Reactive-Advective-Diffusive Models for the Growth of Gliomas Treated with Radiotherapy." Semina: Ciências Exatas e Tecnológicas 44 (June 22, 2023): e47321. http://dx.doi.org/10.5433/1679-0375.2023.v44.47321.
Анотація:
Gliomas are malignant brain tumors responsible for 50% of primary human brain cancer cases. They have a combination of rapid growth and invasiveness, and high fatality rates with a median survival time of one year. Mathematical models that describe its growth have helped to improve treatment. In this paper, a combined model formed by terms of two other models known in the literature is analyzed. The combined model is a Reactive-Advective-Diffusive partial differential equation, which is solved by combining the finite difference method, the Crank-Nicolson method and the upwind method. Logistic growth is used for cell proliferation ensuring a saturation threshold for glioma growth, which is crucial to properly estimate patient survival time. The well-known linear-quadratic radiobiological model is used to describe cell death due to radiotherapy treatment. Two initial conditions are compared in the simulations, indicating the need for further studies to have a model as close as possible to reality. Simulation results are shown for four scenarios: no radiotherapy, application of a single dose, and two dose fractionation schemes.
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Passi, Kamlesh, Than S. Kehwar, Rajesh Vashistha, Bikramjit Singh, Veena Jain, and Sureshchandra J. Gupta. "High-dose-rate brachytherapy with external beam radiotherapy in the treatment of carcinoma of cervix: dosimetric and radiobiologic analysis." Journal of Radiotherapy in Practice 8, no. 4 (December 2009): 215–27. http://dx.doi.org/10.1017/s1460396909990021.
Анотація:
AbstractPurpose: The aim of this study was to find out equivalency between two high-dose-rate (HDR) fractionation schemes, relevance to the International Commission on Radiation Units and Measurements report-38 (ICRU-38) reference volume with respect to point A dose and other ICRU reference points in two-dimensional (2D) planning.Methods and Materials: Forty-nine patients having carcinoma of cervix of stages II–IIIB treated with external beam radiotherapy plus HDR brachytherapy (BT) were analysed. The external beam radiotherapy dose of 45 Gy/25 fractions delivered in 5 weeks followed by HDR BT delivered either in two fractions with 9.5 Gy per fraction (Group-1) or in three fractions with 7.5 Gy per fraction (Group-2) to point A. ICRU-38 recommendations were followed to determine reference volume with respect to Manchester dose point A, and biologically effective dose (BED) at different points.Results: BED10 at bladder and rectum reference points were 17.11 ± 12.36 Gy and 13.92 ± 5.71 Gy in Group-1, and 15.69 ± 11.43 Gy and 16.24 ± 5.45 Gy in Group-2, respectively; and BED3 were 33.03 ± 29.67 Gy and 25.01 ± 12.35Gy in Group-1, and 27.00 ± 26.85 Gy and 27.44 ± 11.00 Gy in Group-2, respectively. The HDR BT reference volumes were 233.47 ± 27.30 cm3 and 227.83 ± 32.35 cm3 and corresponding CBED10 at point A with proliferation correction were 76.59 ± 2.31 Gy, and 76.41 ± 2.15 Gy for Group-1 and Group-2, respectively. The CBED10 and CBED3 at point B were 46.38 ± 2.26 Gy and 82.23 ± 0.72 Gy, respectively, for Group-1; and 45.03 ± 2.11 Gy and 82.89 ± 0.44 Gy, respectively, for Group-2.Conclusion: No significant differences were found in the results of two HDR fractionation schemes. ICRU reference volume with respect to point A dose correlates with tumour control and is a good pre-treatment predictor in 2D planning. Neither ICRU bladder and rectum reference points nor trapezoid points showed correlation with complications. The trapezoid points did not also show any correlation with loco-regional control.
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Horas, Jorge A., Osvaldo R. Olguín, and Marcos G. Rizzotto. "Examining the validity of Poissonian models against the birth and death TCP model for various radiotherapy fractionation schemes." International Journal of Radiation Biology 86, no. 8 (June 29, 2010): 711–17. http://dx.doi.org/10.3109/09553001003734618.
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Arsenev, Andrey, Sergey Novikov, Sergey Kanaev, Anton Barchuk, Andrey Nefedov, F. Antipov, A. Nefedova, and S. Tarkov. "STEREOTACTIC BODY RADIATION THERAPY FOR EARLY-STAGE NON-SMALL CELL LUNG CANCER." Problems in oncology 64, no. 5 (May 1, 2018): 638–44. http://dx.doi.org/10.37469/0507-3758-2018-64-5-638-644.
Анотація:
An active introduction of screening programs potentially leads to a significant increase in the proportion of patients with early forms of non-small cell lung cancer. Surgical treatment, which is the standard of care for localized forms, due to functional limitations can be performed only in 65-70% of patients. The solution to this problem can be found in the improvement of the results of radiotherapy by using modern equipment, the planning systems, improved fractionation schemes and introduction of methods for summing radiation doses. Stereotactic radiotherapy allows high-precision delivery of high radiation dose to tumor with a minimal damage to surrounding healthy tissues. In this literature review based on the analysis of a large number of publications we show that it is not yet possible to make valid conclusions about the effectiveness and safety of stereotactic radiation therapy as an alternative to the surgical methods. It is necessary to plan and conduct randomized trials without further delay taking into account the expected high relevance of the method.
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Ohtakara, Kazuhiro, and Hiroaki Hoshi. "Gradual Recovery from Nonambulatory Quadriparesis Caused by Metastatic Epidural Cervical Cord Compression in an Octogenarian Gallbladder Carcinoma Patient Treated with Image-Guided Three-Dimensional Conformal Radiotherapy Alone Using a Field-in-Field Technique." Case Reports in Oncological Medicine 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/398208.
Анотація:
Radiotherapy for acute metastatic epidural spinal cord compression (MESCC) involves conventional techniques and dose fractionation schemes, as it needs to be initiated quickly. However, even with rapid intervention, few paraplegic patients regain ambulation. Here, we describe the case of a mid-octogenarian who presented with severe pain and nonambulatory quadriparesis attributable to MESCC at the fifth cervical vertebra, which developed 10 months after the diagnosis of undifferentiated carcinoma of the gallbladder. Image-guided three-dimensional conformal radiotherapy (IG-3DCRT) was started with 25 Gy in 5 fractions followed by a boost of 12 Gy in 3 fractions, for which a field-in-field (FIF) technique was used to optimize the dose distribution. Despite the fact that steroids were not administered, the patient reported significant pain reduction and showed improved motor function 3 and 4 weeks after the IG-3DCRT, respectively. Over the following 4 months, her neurological function gradually improved, and she was consequently able to eat and change clothes without assistance and to walk slowly for 10–20 m using a walker. She succumbed to progression of abdominal disease 8.5 months after the IG-3DCRT. This case demonstrates that image-guided FIF radiotherapy with a dose-escalated hypofractionated regimen can potentially improve functional outcome and local control.
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Moore, Assaf, Ido Stav, Robert B. Den, Noa Gordon, Michal Sarfaty, Victoria Neiman, Eli Rosenbaum, and Daniel A. Goldstein. "The Financial Impact of Hypofractionated Radiation for Localized Prostate Cancer in the United States." Journal of Oncology 2019 (January 2, 2019): 1–8. http://dx.doi.org/10.1155/2019/8170428.
Анотація:
Background. Until recently, dose intensified radiotherapy was the standard radiation method for localized prostate cancer. Multiple studies have demonstrated similar efficacy and tolerability with moderate hypofractionation. In recent years there has been an increasing focus placed on understanding the cost and value of cancer care. In this study we aimed to assess the economic impact of moderate hypofractionation for payers in the United States.Methods. We performed a population-based analysis of the total cost of external beam radiotherapy (EBRT) for localized prostate cancer in the US annually. The national annual target population of patients treated with definitive EBRT was calculated using the Surveillance, Epidemiology, and End Results (SEER) database. Treatment costs for various fractionation schemes were based on billing codes and 2018 pricing by the Centers for Medicare and Medicaid Services (CMS).Results. We estimate that 27,146 patients with localized prostate cancer are treated with EBRT annually in the US. The cost of standard fractionation in 45 or 39 fractions is US$26,782 and 23,625 per patient, respectively. With moderate hypofractionation in 28 or 20 fractions, the cost is US$17,793 and 13,402 per patient, respectively. The use of moderate hypofractionation would lead to 25-50% annual savings US$158,315,472-US$363,213,480 in the US.Conclusions. Moderate hypofractionation may have the potential to save approximately US$0.16-0.36 billion annually, likely without impacting survival or tolerability. This may lead to lower personal financial toxicity. It would be reasonable for public and private payers to consider which type of radiation is most suited to reimbursement.
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Pocza, Tamas, Domonkos Szegedi, Tibor Major, and Csilla Pesznyak. "Verification of an optimizer algorithm by the beam delivery evaluation of intensity-modulated arc therapy plans." Radiology and Oncology 55, no. 4 (November 19, 2021): 508–15. http://dx.doi.org/10.2478/raon-2021-0046.
Анотація:
Abstract Background In the case of dynamic radiotherapy plans, the fractionation schemes can have dosimetric effects. Our goal was to define the effect of the fraction dose on the plan quality and the beam delivery. Materials and methods Treatment plans were created for 5 early-stage lung cancer patients with different dose schedules. The planned total dose was 60 Gy, fraction dose was 2 Gy, 3 Gy, 5 Gy, 12 Gy and 20 Gy. Additionally renormalized plans were created by changing the prescribed fraction dose after optimization. The dosimetric parameters and the beam delivery parameters were collected to define the plan quality and the complexity of the treatment plans. The accuracy of dose delivery was verified with dose measurements using electronic portal imaging device (EPID). Results The plan quality was independent from the used fractionation scheme. The fraction dose could be changed safely after the optimization, the delivery accuracy of the treatment plans with changed prescribed dose was not lower. According to EPID based measurements, the high fraction dose and dose rate caused the saturation of the detector, which lowered the gamma passing rate. The aperture complexity score, the gantry speed and the dose rate changes were not predicting factors for the gamma passing rate values. Conclusions The plan quality and the delivery accuracy are independent from the fraction dose, moreover the fraction dose can be changed safely after the dose optimization. The saturation effect of the EPID has to be considered when the action limits of the quality assurance system are defined.
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Revannasiddaiah, Swaroop, Madhup Rastogi, KailashChandra Pandey, NirdoshKumar Pant, Vipul Nautiyal, and ManojKumar Gupta. "Palliative radiotherapy in locally advanced head and neck cancer after failure of induction chemotherapy: Comparison of two fractionation schemes." Indian Journal of Palliative Care 19, no. 3 (2013): 139. http://dx.doi.org/10.4103/0973-1075.121522.
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Kraszkiewicz, Małgorzata, Aleksandra Napieralska, Jerzy Wydmanski, and Wojciech Majewski. "Evaluation of efficacy and tolerance of radical radiotherapy and radiochemotherapy in treatment of locally advanced, unresectable rectal cancer." Journal of Clinical Oncology 40, no. 4_suppl (February 1, 2022): 133. http://dx.doi.org/10.1200/jco.2022.40.4_suppl.133.
Анотація:
133 Background: Evaluation of tolerance and efficacy of two schemes of neoadjuvant treatment in patients with unresectable rectal cancer: radiochemotherapy and radiotherapy, including conventional and accelerated hyperfractionation. Methods: 145 patients (pts) with unresectable, locally advanced rectal cancer. Schemes used: radiotherapy (RT) in 73 (50%) or radiochemotherapy (CRT) in 72 (50%). In RT group conventional fractionation (CFRT) and hyperfractionated accelerated radiotherapy (HART). In CRT 54 Gy in 1.8 Gy fractions was given with two cycles of 5 Fu-LV chemotherapy in three or five day cycles. Results: Objective response (OR) in RT and CRT group was 60% versus 75%. Resection rate (RR) in RT and CRT: 37% versus 65%. Tumor mobility and laparotomy-based unresectability were significant factors for OR. Performance status, tumor mobility, neoadjuvant treatment method were significant for RR. Five-year LC in CRT versus RT: 68% versus 37%. Five-year OS: 52% versus 27%. CRT was independent positive prognostic factor for resection rate, local control. Tumor volume did not reach significance for any of the end points. Lenght of chemotherapy cycles (three or five days) did not reach significance for any of the endpoints. Toxicity was acceptable in both groups. CRT had best outcome in LC: 68% versus 42% in HART; and 25% in CFRT. Five-year OS was much better in CRT than in CFRT: 52% versus 17%. Conclusions: The results of treatment depend on performance status, patients age, tumor mobility and unresectability based on earlier laparotomy. The lack of influence of the tumor volume on all endpoints indicates the need for radical neoadjuvant treatment independently of tumor volume and underlines the key role of a proper surgical treatment. In patients not suitable for CRT, HART is optimal strategy for its better efficacy than CFRT.
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Boguszewicz, Łukasz, Agata Bieleń, Mateusz Ciszek, Jacek Wendykier, Krzysztof Szczepanik, Agnieszka Skorupa, Jolanta Mrochem-Kwarciak, Krzysztof Składowski, and Maria Sokół. "NMR-Based Metabolomics in Investigation of the Radiation Induced Changes in Blood Serum of Head and Neck Cancer Patients and Its Correlation with the Tissue Volumes Exposed to the Particulate Doses." International Journal of Molecular Sciences 22, no. 12 (June 11, 2021): 6310. http://dx.doi.org/10.3390/ijms22126310.
Анотація:
In the present study, we analyze the nuclear magnetic resonance (NMR) blood serum metabolic profiles of 106 head and neck squamous cell carcinoma (HNSCC) patients during radio (RT) and concurrent radio-chemotherapy (CHRT). Four different fractionation schemes were compared. The blood samples were collected weekly, from the day before the treatment until the last week of CHRT/RT. The NMR spectra were acquired on A Bruker 400 MHz spectrometer at 310 K and analyzed using multivariate methods. Seven metabolites were found significantly to be altered solely by radiotherapy: N-acetyl-glycoprotein (NAG), N-acetylcysteine, glycerol, glycolate and the lipids at 0.9, 1.3 and 3.2 ppm. The NMR results were correlated with the tissue volumes receiving a particular dose of radiation. The influence of the irradiated volume on the metabolic profile is weak and mainly limited to sparse correlations with the inflammatory markers, creatinine and the lymphocyte count in RT and the branched-chain amino-acids in CHRT. This is probably due to the optimal planning and delivery of radiotherapy improving sparing of the surrounding normal tissues and minimizing the differences between the patients (caused by the tumor location and size).