Дисертації: "Tumors Measurement"

1

Verleyen, Wim. "Machine learning for systems pathology." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4512.

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Systems pathology attempts to introduce more holistic approaches towards pathology and attempts to integrate clinicopathological information with “-omics” technology. This doctorate researches two examples of a systems approach for pathology: (1) a personalized patient output prediction for ovarian cancer and (2) an analytical approach differentiates between individual and collective tumour invasion. During the personalized patient output prediction for ovarian cancer study, clinicopathological measurements and proteomic biomarkers are analysed with a set of newly engineered bioinformatic tools. These tools are based upon feature selection, survival analysis with Cox proportional hazards regression, and a novel Monte Carlo approach. Clinical and pathological data proves to have highly significant information content, as expected; however, molecular data has little information content alone, and is only significant when selected most-informative variables are placed in the context of the patient's clinical and pathological measures. Furthermore, classifiers based on support vector machines (SVMs) that predict one-year PFS and three-year OS with high accuracy, show how the addition of carefully selected molecular measures to clinical and pathological knowledge can enable personalized prognosis predictions. Finally, the high-performance of these classifiers are validated on an additional data set. A second study, an analytical approach differentiates between individual and collective tumour invasion, analyses a set of morphological measures. These morphological measurements are collected with a newly developed process using automated imaging analysis for data collection in combination with a Bayesian network analysis to probabilistically connect morphological variables with tumour invasion modes. Between an individual and collective invasion mode, cell-cell contact is the most discriminating morphological feature. Smaller invading groups were typified by smoother cellular surfaces than those invading collectively in larger groups. Interestingly, elongation was evident in all invading cell groups and was not a specific feature of single cell invasion as a surrogate of epithelialmesenchymal transition. In conclusion, the combination of automated imaging analysis and Bayesian network analysis provides an insight into morphological variables associated with transition of cancer cells between invasion modes. We show that only two morphologically distinct modes of invasion exist. The two studies performed in this thesis illustrate the potential of a systems approach for pathology and illustrate the need of quantitative approaches in order to reveal the system behind pathology.

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2

Kavanagh, Mary-Claire Anne. "Measurement of oxygen levels in murine tumours." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0009/NQ41447.pdf.

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3

Collingridge, David Roy. "Measurement and manipulation of tumour oxygen tension." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299928.

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4

Calhoun, Mark A. II. "Measurement and Variation of the Mechanical Environment in Glioblastoma." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503252735120506.

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5

Lawton, Patricia Ann. "The measurement of intrinsic cellular radiosensitivity in human tumours and normal tissues." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283750.

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6

Warmuth, Carsten. "Nichtinvasive Magnetresonanz-Perfusionsmessung des Gehirns mittelsMagnetischer Blutbolusmarkierung(Spin-Labeling)." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2003. http://dx.doi.org/10.18452/15025.

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Die magnetische Blutbolusmarkierung (Spin-Labeling) ermöglicht die nichtinvasive quantitative Messung des Blutflusses im Gewebe. Beim Spin-Labeling wird arterielles Blut durch Radiofrequenzpulse magnetisch markiert und der Transport der Markierung MR-tomographisch gemessen. Am Modell einer unter physiologischen Bedingungen perfundierten extrakorporalen Schweineniere konnte die Quantifizierbarkeit der Messmethode nachgewiesen werden. In einer Studie an 36 Hirntumorpatienten wurde das Verfahren mit der kontrastmittelbasierten First-Pass-Bolus-Methode zur nicht-quantitativen Perfusionsmessung verglichen. Es zeigte sich eine sehr gute Übereinstimmung zwischen beiden Methoden, der lineare Korrelationskoeffizient des relativen Blutflusses in der Tumorregion lag bei R=0,83. Die mittels Spin-Labeling ermittelten Absolutwerte des Blutflusses spielen bei der Beurteilung des Tumorgrades eine untergeordnete Rolle, da die mittlere Perfusion individuell sehr verschieden ist. Ein zweiter Anwendungsbereich für das Spin-Labeling ist die Darstellung großer Arterien. Spin-Labeling ermöglicht die nichtinvasive dynamische Angiographie (Dynamische Spin-Labeling-Angiographie - DSLA). Analog zur digitalen Subtraktionsangiographie kann damit der Einstromvorgang des Blutes in den Gefäßbaum zeitaufgelöst gemessen werden, jedoch mit wesentlich höherer zeitlicher Auflösung und frei wählbarer Projektionsrichtung. In einer Studie an 18 Patienten mit einseitigen Carotisstenosen wurden die Zeitdifferenzen der Anflutung der zerebralen Gefäße zwischen der betroffenen und der nicht stenosierten Seite bestimmt. Die im Carotis-Siphon gemessenen Zeitdifferenzen korrelieren signifikant mit dem Stenosegrad, steigen aber erst ab einer Lumeneinengung oberhalb von 80 Prozent deutlich an. Im Vergleich zu den etablierten Methoden werden die Möglichkeiten und Grenzen der DSLA dargestellt.
Arterial spin labeling methods allow to determine quantitative tissue blood flow values noninvasively. Arterial blood is labelled by an inversion pulse and the distribution of this intrinsic tracer is measured using magnetic resonance imaging. Experiments using an extra corporal in-vitro porcine kidney in a MR compatible set-up were carried out to determine the accuracy of blood flow values calculated from arterial spin labeling measurements. In a study of 36 brain tumor patients, spin labeling was compared to non-quantitative contrast-enhanced dynamic susceptibility-weighted perfusion imaging. Relative blood flow values determined with both methods were in good agreement, the linear regression coefficient in the tumor region was R=0.83. Due to the variable individual perfusion state, quantitative blood flow values determined using spin labeling play a minor role in the assessment of tumor grade. Application of spin labeling to angiography of major arteries was investigated. Dynamic spin labeling angiography (DSLA) sequences were implemented and tested on a clinical scanner. This technique allows time-resolved depiction of blood flow in large vessels with very high temporal resolution. As opposed to digital subtraction angiography, the method allows arbitrary projection directions. In a study, 18 patients with one-sided carotid stenoses were examined. In these patients the time differences of blood bolus arrival at both hemispheres were determined. Time differences measured in the carotid siphon show a significant correlation with the degree of stenosis. However, a clear increase is not seen until 80% narrowing of a carotid. Possibilities and limitations of the DSLA method are discussed in comparison to established techniques.

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7

McHugh, Damien Joseph. "The effect of tumour microstructure on diffusion-weighted MRI measurements." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/the-effect-of-tumour-microstructure-on-diffusionweighted-mri-measurements(9821717e-df69-4dd0-baf7-51cf27a18aa2).html.

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By sensitising the magnetic resonance signal to the diffusion of water molecules in tissue, diffusion-weighted magnetic resonance imaging provides a means of assessing tumour microstructure non-invasively. Such measurements have the potential to provide important information about tumour development and the response of tumours to treatment, but the way in which different tissue properties affect the diffusion-weighted signal remains unclear. Through simulations, in vivo studies and phantom experiments, this thesis investigates the relationship between the diffusion-weighted signal, the pulse sequence parameters used for acquisition, and microstructural properties of tumours. The use of oscillating gradient pulse sequences on a clinical scanner was investigated initially, with theoretical and practical considerations leading subsequent work to focus on pulsed gradient sequences. The forward problem of predicting the diffusion-weighted signal for given combinations of tissue properties and sequence parameters was addressed numerically through Monte Carlo simulations, focussing on how tumour cell size, intracellular volume fraction and membrane permeability affect the signal. These simulations allowed the sensitivity of the signal to changes in these tissue properties to be investigated, revealing how sensitivity depends on sequence parameters as well as the specific microstructural configuration. By repeating the simulations using the specific sequence parameters used in a clinical and preclinical study, the sensitivity of the implemented protocols was assessed, and linked to the experimental findings. The preclinical study illustrated the importance of the diffusion time in determining the sensitivity to treatment-induced changes in tumours, with larger post-treatment signal changes observed at longer diffusion times. These trends were qualitatively reflected in the sensitivity analysis derived from the simulations. Finally, the inverse problem of estimating microstructural properties from the diffusion-weighted signal was addressed using a physical phantom designed as a simple mimic of tumour tissue. By fitting a biophysical model to the diffusion data, the size and volume fraction of the approximately spherical 'cells' were estimated. The radius was slightly underestimated compared with that determined from independent measurements, the fitted volume fraction was plausible, and parameters were found to be estimated with reasonably good precision.

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8

Ghara'ati, H. "The use of tomography images in the XRF measurement of platinum in tumours following chemotherapy." Thesis, Swansea University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637048.

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The technique of X-ray fluorescence of heavy elements is widely used in medical physics and has been used for tracing the platinum-based drugs administered for the treatment of malignant tumours. A method is developed for analyzing an in vivo XRF system and optimizing the system for measuring the absorption of platinum in the target. The nature of the emitted radiation and its interaction with materials are explained. The general principles of the Monte Carlo method are described. A flexible program for an annular source/collimator and back-scattering geometry is developed. Several techniques are employed to improve the statistics and the program calculates the XRF spectrum for several heavy elements simultaneously. The dimensions and shielding materials of the source collimator are investigated in detail. The results support the choice of tungsten with a thin lining of tin or copper. The background spectrum contains a prominent Compton peak, the region above this containing mainly singly-scattered photons and the region below mainly multiply-scattered photons (plus the target element K-line). Very few of these multiply-scattered photons originate in the phantom, and the high background observed experimentally in the low-energy region is therefore attributed to scattering on the surface of the detector collimator. A design is proposed which would reduce this scattering considerably. A matrix of detection sensitivity versus depth and radius of the field is obtained. To calculate the response due to the tumour one can integrate the sensitivity over the volume of the tumour using data obtainable from tomographic images (like CT or MRI). It is also found that the regions of producing the greatest number of K-photons are not directly visible from the detector. A design is proposed which corrects for this deficiency and should therefore greatly improve the detection limit.

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9

Richter, Johan. "Fluorescence Guided Resection of Brain Tumors : Evaluation of a Hand-held Spectroscopic Probe." Doctoral thesis, Linköpings universitet, Institutionen för medicinsk teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139793.

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Malignant gliomas grow infiltrative in the brain and can therefore not be completely removed by neurosurgical means. However, for an optimized oncological treatment it has proven useful to resect as much as possible of tumor. The identification of the tumor in the marginal zone is difficult but crucial. Studies have shown that visualization of the specific enhancement of 5-aminolevulinic acid(5-ALA) in the tumor can help to maximize the resection. The Department of Biomedical Engineering, Linköping University, has developed an optical hand-held probe (HHP) to identify tumor tissue with a high sensitivity by means of fluorescence spectroscopy. The technical design and the optical properties of the probe were gradually developed in a standard neurosurgical setting during resection of malignant gliomas. The device could easily be implemented in the operating room, meeting all requirements in terms of sterile handling and without interference of any kind with other equipment. The integration of the device in a navigation system and its use in combination with a blue light surgical microscope were simple. Measurements in 27 operations during resection of malignant gliomas were compared to results from biopsies from the same tumor locations. The equipment was tested as a stand-alone device (n = 180), integrated in a navigation system or in combination with the blue light microscope (n = 190). A ratiocal culated from the measurements enabled objective and comparable values for different tissue types, in correspondence with the findings from the histopathological examinations and in accordance with the navigation system as well as with the surgical microscope.The marginal zone was explored and tumor fluorescence could be identified beyond the fluorescence as seen through the microscope. A higher sensitivity of the HHP was confirmed; the specificity was lower. The combined use of the HHP with a navigation system and with asurgical microscope was beneficial.
Maligna hjärntumörer växer infiltrerande i hjärnan och kan därförinte helt avlägsnas genom kirurgiska operationer. För en optimerad behandling har det emellertid visat sig vara av värde att avlägsna såmycket som möjligt av tumörvävnaden. Identifiering av tumören i gränszonen är mycket svårt, men avgörande. Studier har visat att visualisering av den specifika laddningen av 5-aminolevulinsyra (5-ALA) i tumören kan bidra till att maximera resektionen. Institutionen för Medicinsk Teknik (IMT) på Linköpings universitet,har utvecklat en liten handhållen optisk prob (HHP) för att identifiera tumörvävnad med hög känslighet med hjälp avfluorescens-spektroskopi. Den tekniska konstruktionen och de optiska egenskaperna hos proben utvecklades stegvis genom testning i flera neurokirurgiska operationer för resektion av maligna gliom. Utrustningen uppfyllde alla krav när det gällde steril hantering i operationssalen och kunde användas utan störningar av något slag med annan operationsutrustning. Integreringen i ett navigerings-system och användningen i kombination med ett kirurgiskt mikroskop för fluorescens-styrd kirurgi var oproblematiska. Mätningar under 27 operationer vid resektion av maligna gliom jämfördes med resultat från biopsier från samma tumörtagningsställen. Utrustningen testades såväl som en fristående enhet (n = 180) och som integrerad i ett navigationssystem eller i kombination med mikroskopet (n =190). En särskild kvot beräknad ur mätningarna möjliggjorde objektiva och jämförbara värden för olika vävnader, i överensstämmelse med resultaten från de vävnadspatologiska undersökningarna och i överensstämmelse med navigationssystemet såväl som med det kirurgiska mikroskopet. Tumörernas gränszon undersöktes och tumörfluorescens kunde identifieras bortom fluorescensen som mikroskopet visade. En högre känslighet hos HHP bekräftades; specificiteten var lägre. Den kombinerade användningen av HHP med ett navigationssystem och med ett kirurgiskt mikroskop visade sig vara fördelaktig.

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10

Leach, Eric. "KNOWLEDGE BASED MEASUREMENT OF ENHANCING BRAIN TISSUE IN ANISOTROPIC MR IMAGERY." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3341.

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Medical Image Analysis has emerged as an important field in the computer vision community. In this thesis, two important issues in medical imaging are addressed and a solution for each is derived and synergistically combined as one coherent system. Firstly, a novel approach is proposed for High Resolution Volume (HRV) construction by combining different frequency components at multiple levels, which are separated by using a multi-resolution pyramid structure. Current clinical imaging protocols make use of multiple orthogonal low resolution scans to measure the size of the tumor. The highly anisotropic data result in difficulty and even errors in tumor assessment. In previous approaches, simple interpolation has been used to construct HRVs from multiple low resolution volumes (LRVs), which fail when large inter-plane spacing is present. In our approach, Laplacian pyramids containing band-pass contents are first computed from registered LRVs. The Laplacian images are expanded in their low resolution axes separately and then fused at each level. A Gaussian pyramid is recovered from the fused Laplacian pyramid, where a volume at the bottom level of the Gaussian pyramid is the constructed HRV. The effectiveness of the proposed approach is validated by using simulated images. The method has also been applied to real clinical data and promising experimental results are demonstrated. Secondly, a new knowledge-based framework to automatically quantify the volume of enhancing tissue in brain MR images is proposed. Our approach provides an objective and consistent way to evaluate disease progression and assess the treatment plan. In our approach, enhanced regions are first located by comparing the difference between the aligned set of pre- and post-contrast T1 MR images. Since some normal tissues may also become enhanced by the administration of Gd-DTPA, using the intensity difference alone may not be able to distinguish normal tissue from the tumor. Thus, we propose a new knowledge-based method employing knowledge of anatomical structures from a probabilistic brain atlas and the prior distribution of brain tumor to identify the real enhancing tissue. Our approach has two main advantages. i) The results are invariant to the image contrast change due to the usage of the probabilistic knowledge-based framework. ii) Using the segmented regions instead of independent pixels facilitates an approach that is much less sensitive to small registration errors and image noise. The obtained results are compared to the ground truth for validation and it is shown that the proposed method can achieve accurate and consistent measurements.
M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE

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11

Carter, Paul Gareth. "The measurement of urinary #beta# core in women with lower genital tract cancer and its prognostic significance." Thesis, Queen Mary, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298463.

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12

Jayasundar, Rama. "Magnetic resonance studies in oncology : measurement of the effects of hyperthermia on tumour pH." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335171.

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13

Henderson, Elizabeth. "Measurement of blood flow, blood volume and capillary permeability in breast tumours using contrast-enhanced magnetic resonance imaging." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/NQ58134.pdf.

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14

Heikkonen, Jorma. "Partition coefficients and tumour blood flow measurements using radioactive 41Ar, 85mKr and 133Xe." Helsinki : Soc. Scient. Fennica, 1988. http://catalog.hathitrust.org/api/volumes/oclc/64258891.html.

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15

Dong, Lixin. "DIFFUSE OPTICAL MEASUREMENTS OF HEAD AND NECK TUMOR HEMODYNAMICS FOR EARLY PREDICTION OF CHEMO-RADIATION THERAPY OUTCOMES." UKnowledge, 2015. http://uknowledge.uky.edu/cbme_etds/35.

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Chemo-radiation therapy is a principal modality for the treatment of head and neck cancers, and its efficacy depends on the interaction of tumor oxygen with free radicals. In this study, we adopted a novel hybrid diffuse optical instrument combining a commercial frequency-domain tissue oximeter (Imagent) and a custom-made diffuse correlation spectroscopy (DCS) flowmeter, which allowed for simultaneous measurements of tumor blood flow and blood oxygenation. Using this hybrid instrument we continually measured tumor hemodynamic responses to chemo-radiation therapy over the treatment period of 7 weeks. We also explored monitoring dynamic tumor hemodynamic changes during radiation delivery. Blood flow data analysis was improved by simultaneously extracting multiple parameters from one single autocorrelation function curve measured by DCS. Patients were classified into two groups based on clinical outcomes: a complete response (CR) group and an incomplete response (IR) group with remote metastasis and/or local recurrence within one year. Interestingly, we found human papilloma virus (HPV-16) status largely affected tumor homodynamic responses to therapy. Significant differences in tumor blood flow index (BFI) and reduced scattering coefficient (μs’) between the IR and CR groups were observed in HPV-16 negative patients at Week 3. Significant differences in oxygenated hemoglobin concentration ([HbO2]) and blood oxygen saturation (StO2) between the two groups were found in HPV-16 positive patients at Week 1 and Week 3, respectively. Receiver operating characteristic curves were constructed and results indicated high sensitivities and specificities of these hemodynamic parameters for early (within the first three weeks of the treatment) prediction of one-year treatment outcomes. Measurement of tumor hemodynamics may serve as a predictive tool allowing treatment selection based on biologic tumor characteristics. Ultimately, reduction of side effects in patients not benefiting from radiation treatment may be feasible.

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16

De, Jaeger Katrien. "Relationship between polarographic oxygen measurements, metastatic ability and EF5 binding in murine tumour models." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ46062.pdf.

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17

Bennett, C. A. "The optimisation of an X-Ray fluorescence system for the in vivo measurement of platinum in head and neck tumours." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636079.

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There is still much information to be gained on the pharmacokinetics of platinum based chemotherapy agents such as cisplatin, and its second generation analogue, carboplatin. A ^99mTc based XRF system in backscatter geometry has been re-introduced in Swansea, for the in vivo measurement of platinum uptake in head and neck tumours. The minimum detection limit (MDL) was found to be 21 ppm for a tumour depth of 10 mm, increasing to 40 ppm for a depth of 20 mm, for a skin dose of 9 mGy. In vivo measurements were therefore limited to superficial tumours only. Eight patients underwent a total of fifteen measurements using the ^99mTc system. The MDL was exceeded in five of these measurements. Replacing the ^99m Tc source with ¹³³Xe, and optimising the collimator-to-skin distance, improved the sensitivity of the system for tumour depths less than 15 mm. The MDL was reduced to 15 ppm at a depth of 10 mm, for the same skin dose. The sensitivity of the Swansea in vivo XRF system was significantly improved by the introduced of a polarised x-ray source. A clinical orthovoltage x-ray unit (Pantak DXT-300), which is routinely used for radiotherapy treatments, was adapted for this purpose. Experimental investigation into the effect of varying the operating voltage, polarising material and additional filtration on the system sensitivity, showed that the optimum combination consisted of a copper polariser, 0.25 mm of additional tin filtration in the primary beam and an operating voltage of 220 kV. The MDL at a depth of 20 mm was 8 ppm for the optimised system, with a corresponding skin dose of approximately 3 mGy. This represents more than an 80% reduction in the MDL compared to the ^99mTc based system, enabling the measurement of deeper tumours, with increased sensitivity.

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18

Toma-Dasu, Iuliana. "Theoretical modelling of tumour oxygenation and influences on treatment outcome." Doctoral thesis, Umeå University, Radiation Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-262.

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One of the main problems in curing cancer resides in the different microenvironment existing in tumours compared to the normal tissues. The mechanisms of failure are different for radiotherapy and chemotherapy, but they all relate to the poor blood supply known to exist in tumours. It is therefore very important to know the tumour microenvironmental conditions in order to devise techniques that will overcome the problems and will therefore improve the result of the treatment.

The aims of the thesis were the modelling of tumour oxygenation and the simulation of polarographic oxygen measurements in order to assess and possibly to improve the accuracy of the electrode in measuring tumour oxygenation. It also aimed to evaluate the implications of tumour microenvironment for the radiotherapy outcome.

The project used theoretical modelling as the main tool. The processes of oxygen diffusion and consumption were described mathematically for different conditions, the result being very accurate distributions of oxygen in tissues. A first simple model of tissue oxygenation was based on the oxygen diffusion around a single blood vessel. A more complex model built from the basic physical processes and measurable parameters allowed the simulation of realistical tissues with heterogeneous vasculature. This model also allowed the modelling of the two types of hypoxia known to appear in tumours and their influence on the tumour microenvironment. The computer simulation of tissues was also used for assessing the accuracy of the polarographic technique for measuring tumour oxygenation.

The results of this study have shown that it is possible to model theoretically the tissue oxygenation starting from the basic physical processes. The particular application of our theoretical simulation to the polarographic oxygen electrode has shown that this experimental method does not give the oxygen values in individual cells. Because the electrode measures the average oxygenation in a relatively large tissue volume, the resulting oxygen distributions are different from the real ones and the extreme high and low values are not detected. It has further been found that the polarographic electrode cannot make distinction between various types of hypoxia existing in tumours, the geometrical distribution of the hypoxic cells influencing mostly the accuracy of the measurement.

It was also shown that because of the averaging implied by the measurement process, electrode results should not be used directly to predict the response to radiation. Thus, the differences between the predictions in clinical tumour control obtained from the real or the measured oxygenations are of the order of tens of percents in absolute value. A method to improve the accuracy of the electrode, i.e. to improve the correlation between the results of the measurements and the actual tissue oxygenation, was proposed.

In conclusion, theoretical modelling has been shown to be a very powerful tool for predicting the outcome of radiotherapy and it has the advantage of describing the tumour oxygenation in the least invasive manner. Furthermore it allows the investigation of the invasiveness and the accuracy of various experimental methods.

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19

Lowndes, Shannely. "Blood interference in fluorescence spectrum : Experiment, analysis and comparison with intraoperativemeasurements on brain tumor." Thesis, Linköpings universitet, Biomedicinsk instrumentteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-60676.

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The optical touch pointer (OTP), a fluorescence spectroscopy based system, assists brain surgeons during guided brain tumor resection in patients with glioblastoma multiforme (GBM). After recording and analyzing the autofluorescence spectrum of the tissue, it is possible to distinguish malignant from healthy brain tissue. A challenge during the intraoperative measurements is the interference of blood. If it gets in contact with the laser pointer, the blood blocks the light transmission to and from the tissue. The purposes of the project were to study and categorize patterns of blood interference and to present possible solutions to avoid signal blocking by blood. To measure fluorescence and reflection two devices were used respectively, the OTP which has a spectrometer and a blue laser, and the diffused reflection spectroscopy system (DRS) which has a spectrometer and a white light source. Both operate independently from each other and are connected to a fiber optical probe. A similar scenario to the one in the operation theater was simulated in the lab. Fluorescence and diffuse reflection measurements with and without blood were realized on skin and on two different plastic fluorescent standards. The results were analyzed with the aid of MatLAB, and compared with data collected in the hospital during brain tumor resection. The highest autofluorescence of brain tissue and skin is reached at approximately 506 nm. Although skin and both plastic standards have different optical properties regarding color or rather fluorescence, all of them presented very similar curves when blood on them blocked partially or completely the light transmission. A blood layer of more than 0.1 mm thickness blocks the blue laser light. Blood absorption happens at 541 and 577 nm due to oxy-hemoglobin (HbO2) in both liquid and dried blood. When the fluorescence spectrum is available but weak, the reflection spectrum contains two dips (traces of HbO2 at 541 and 577 nm). In brain there were cases in which light absorption occurred additionally at other wavelengths than the absorption peaks of deoxyhemoglobin (Hb) and HbO2. Blood interference during the OP can be prevented if the probe rests in a saline solution after every measurement. In this way the fresh blood sticking on the probe dissolves in the solution. For dried or coagulated blood, additional manual cleansing is needed.

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20

Sellner, Stefan [Verfasser], and Joachim [Akademischer Betreuer] Ullrich. "Simulations, Optimizations, and Microdosimetric Measurements of Beam Quality for Heavy-Ion Tumor Therapy. A charged (particle) issue. / Stefan Sellner ; Betreuer: Joachim Ullrich." Heidelberg : Universitätsbibliothek Heidelberg, 2013. http://d-nb.info/1177810581/34.

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21

Islam, Naimul. "The potential for using combined electrical impedance and ultrasound measurements for the non-invasive determination of temperature in deep body tumours during mild hyperthermia." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/56721/.

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The effectiveness of mild hyperthermia in improving the outcome of radiotherapy and chemotherapy treatment is well established for surface tumours (e.g. an average improvement of 20% in the 5 years survival rate using mild hyperthermia in conjunction with radiotherapy). However, to apply this technique to deep body solid tumours clinically, a non-invasive thermometry method is needed. Several approaches have been proposed for non-invasive thermometry in the past but none were capable of providing 3D temperature distributions in-vivo with the required accuracy. In this thesis, the potential for determining the temperature in a deep body solid tumour during mild hyperthermia by combining ultrasound propagation velocity and electrical impedance measurement techniques has been investigated. Simultaneous ultrasound propagation velocity and electrical impedance measurements were made in-vitro on liver, fat and layered fat-liver samples as the temperature was increased to mild hyperthermia levels (45°C max.). From the ultrasound measurements a linear correlation was found between the percentage of fat in the sample and the change in ultrasound propagation velocity with temperature (-0.12ms-1°C-1%-1, r2 = 0.93). Analysis of the data from the multi-frequency electrical impedance measurements showed that the magnitude of the electrical impedance measured at 256kHz normalised to the magnitude of the electrical impedance measured at 8kHz gave a linear correlation with the percentage of fat in the sample (0.003 %-1, r2 = 0.72) but no statistically significant correlation between the fat content and the temperature coefficient at 256kHz (r2 = 0.007, p >0.05). These results support an approach of using high to low frequency impedance ratios to determine the percentage of fat in the tissue and then this together with an ultrasound propagation velocity measure to detect the change in the temperature of the tissue. Application of this technique is limited by the variation in the change in ultrasound propagation velocity with temperature between tissue samples found in this study but the origins of this are unclear. In addition, further improvements in the spatial sensitivity of the tetrapolar impedance measurements are necessary to ensure an adequate spatial determination of fat content.

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22

Setoyama, Takeshi. "Development of novel bioassay for the measurement of bioactive insulin-like growth factors in blood samples and treatment strategy targeting the bioactive insulin-like growth factors for non-islet cell tumor hypoglycemia." Kyoto University, 2016. http://hdl.handle.net/2433/204576.

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23

Lignon, Dominique. "Élaboration d'un dispositif adapte a la photochimiothérapie des tumeurs de vessie : électronique, capteurs, traitement du signal et contrôle de la dosimétrie laser." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL053N.

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Les tumeurs superficielles de la vessie ou carcinome in situ (maladie de la muqueuse) sont les indications les plus intéressantes de la PDT, car pouvant éviter une cystectomie totale mutilante. La plurifocalité des lésions impose un traitement de l'ensemble de la paroi interne vésicale; la PDT de vessie consiste à délivrer, une quantité d'énergie homogène sur toute la surface de l'urothelium vésical, suffisante pour induire un effet thérapeutique sur les sites tumoraux et non toxiques pour les tissus sains. Dans ce but, nous avons développé un système de traitement et de contrôle dosimétrique intravésical où l'operateur puisse disposer d'une information précise sur la répartition de la lumière dans la vessie, qui lui permette d'optimiser le positionnement de la source d'irradiation. Le dispositif intravésical comporte douze capteurs lumineux isotropiques à fibre optique repartis symétriquement contre les parois de la vessie, la source d'émission est constituée d'une sphère diffusante isotrope. Les signaux lumineux issus des capteurs sont convertis en tension. La partie acquisition des valeurs du système comporte deux voies: une voie analogique, les valeurs sont multiplexées sur une même trace d'oscilloscope, nous pouvons ainsi voir en temps réel leur évolution en fonction de la position de la source d'émission. L'autre voie est constituée par l'acquisition numérique des valeurs en vue de leur analyse. Nous avons développé un programme de centrage du diffuseur qui nous indique sa position dans la vessie, ainsi qu'un programme de cartographie des différents niveaux d'éclairement du tissu vésical

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24

Shih, Yih-Lih, and 施易利. "NIR Electro-optical Measurement and Analysis for the Heterogeneous Intralipid Phantoms Imitating Breast Tumors." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/08906851644095925933.

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碩士
國立中央大學
機械工程研究所
94
Near infrared (NIR) diffuse optical tomography (DOT) is a new medical imaging modality, the advantages are safe (longer wavelength) and non-radioactive, in spite of its low spatial resolution at the current phase. Due to the diagnostic potential of NIR,the abnormality of tissues in NIR light is to allow earlier detection rather than most other imaging modalities. This thesis describes the NIR Electro-optical measurement for Intralipid phantoms using our own developed NIR DOT scanning instrument with highly spatially angular resolution, in order to investigate the influence of different factors such as the off-boundary, the volume density (v.d.) of inclusion, and the size ratio. The influence of each condition also can reveal the real condition of biomedical tissue, and this information can offer the doctor for diagnosis. This thesis discusses Intralipid phantoms which are the homogeneous background with one inclusion or two inclusions. For the homogeneous background with one inclusion and the source position at s0 , the contrast is large, the resolution of inclusion position is good but the resolution of inclusion size is bad. The off-boundary is small, the resolution of contrast and inclusion size are both good. The inclusion size is large, the resolution of contrast is good but the resolution of off-boundary is bad. For the homogeneous background with two inclusions and the source position at s0 , the contrast (I0) is large; the resolution of inclusion position is good. The off-boundary (I0) is small confined to the non-directly detected inclusion (I4) with small v.d.; the resolution of contrast is good. The common conclusion for the homogeneous background with one inclusion and two inclusions can be obtained. Those phenomena are similar in some condition, especially for source position at s0 and Sπ. This thesis also simulates a power curve by using an exponential form. The light trajectory of model in this thesis was set as straight line, unlike the real trajectory. The outcome does not seem well. From this thesis, it can give a general concept about the influence of different factors. Furthermore, the original experimental data can be used as the input and the calibration of image reconstruction.

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25

Lin, Chih-Huang, and 林志泓. "3D Measurements of Ultrasonic Image of Ovarian tumor." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/90235804066474455228.

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碩士
義守大學
電子工程學系
87
3D Measurements of Ultrasonic Image of Ovarian tumor Chih-Huang Lin* Ching-Fen Jiang** Dept. of Electronic Engineering ,I-Shou University Kaohsiung, Taiwan, ROC Abstract Ovarian cancer is one of the most mortal female cancers in the civilized countries. Ultrasonic technique is a popular detection facility. In the way to judge the ovarian tumor malignancy on the Ultrasonic image, doctor usually look for the surface of the ovarian tumor. If the surface of the ovarian tumor is irregularity, there will be a prevalence with which the tumor is ovarian cancer. However, it is not easy to quantify the irregularity of the ovarian tumor in the 2D ultrasonic image. Therefore a quantitative analysis of the complexity of 3D surface of ovarian tumor can assist doctors to improve the correctness of the diagnosis. In this study, We firstly developed a new method to detect the 3D contour of the ovarian tumor. Our new method was based on the classified image of ovarian. Previous works of the classified image of ovarian tumor have provided us an well-contrast image for edge detection. After edge detection of ovarian tumor, we make used of the Fractal model to analysis the complexity of the 3D surface of ovarian tumor. Fractal dimension is not a integer dimension. In addition, the more complicated the object is, the higher the fractal dimension of the object have. According to the property of fractal dimension, the irregular degree of ovarian tumor was successfully determined. Key word :3D ultrasonic image, ovarian tumor, Fractal geometry, Fractal dimension *The author **The advisor

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26

Huang, Shu-wei, and 黃書偉. "Measurement Tumor Vessels of the Nude Mice Using Photoacoustic Tomography Imaging." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/23584555601266489890.

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碩士
國立陽明大學
醫學工程研究所
94
Photoacoustic imaging (PAI) has been shown to have higher spatial resolution and optical contrast than conventional ultrasound imaging due to the high contrast absorption of blood vessels to green and near infrared (NIR) light. Hemoglobin is the most significant optical absorber in human blood; it offers strong optical contrast at 532nm optical wavelengths and makes the photoacoustic technique particularly well suited for imaging blood vessels. The photoacoustic system includes a Nd:YAG laser, operating at 532 nm wavelength, a 2.25MHz and 20MHz ultrasonic transducer, an X-Y axes piezo ceramic stage, and a computer user interface. Utilizing synthetic aperture technique improved the time delay of photoacoustic image, obtained better image resolution and signal-to-noise ratio (SNR), the SNR was improved about 3dB. We measured the photoacoustic imaging resolution about 0.7mm using 20MHz ultrasonic transducer. This study can divide plane scanning and depth scanning. In plane scanning, we scanned hair and 10 days chicken embryo, can differentiable vessels distribution. In depth scanning, we measured blood vessels form human cutaneous veins and 3-21 days tumors of the nude mice in-vivo. A series of 2D photoacoustic imaging of the blood vessels of the human forearm can differentiable vessels distribution at different place. In tumors of the nude mice, using photoacoustic imaging compared with ultrasound imaging, we observe that the photoacoutic signals change with the growth of the tumor, blood concentration change inside the tumor and growth in depth of the neovascularized region. In clinical, we expect photoacoustic technique detected neovascularized in tumor noninvaded.

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27

Wu, Meng-Shu, and 吳孟書. "Collection and Impedance Measurement of Circulating Tumor Cells from the Whole Blood Samples." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/22859777715022347744.

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Анотація:

碩士
國立中正大學
機械工程學系暨研究所
103
The detection of rate cells, such as circulating tumor cells (CTCs), circulating fetal cells, is important for medical diagnostics and characterization. In order to detect tumor cells precisely, the red blood cells and white blood cells buffer lysis were added to the whole blood sample before measuring. The RBCs (Red blood cells) and WBCs (white blood cells) were lysed and the experimental result was found that the survival rate of HeLa was about 80 %. However, the survival rate of RBCs was around only 10 %. The main purpose of this study is to trap cancerous cells (HeLa) in the proposed microchip, then measure the impedance of HeLa cells using lock-in amplifier after lysing blood cells. Circular microelectrodes were fabricated by the standard photolithography technique to trap the positive dielectrophoretic cells by applying a AC voltage of 5 to 10 Vpp with a frequency of 1 MHz. After cells were captured, a measuring AC of 1 Vpp with 4 kHz was applied. Meanwhile, the flow rate of 1 μL/min was also applied to reduce the loss rate of captured cells to approximately 5 – 8 %.This microfluidic device is easy to operate and integrate into further biomedical applications and technology. The detection of cancerous cells in the microchip proposed herein is sensitive and the interference of blood cells could be avoided.

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28

Al-Hallaq, Hania A. "Measurement of changes in tumor oxygenation by high spectral and spatial resolution MRI /." 2000. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9977996.

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29

Fichtner, Nicole Damara. "MR Diffusion Measurements of Apoptotic Changes in Tumour Cells." Thesis, 2013. http://hdl.handle.net/1807/35606.

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Monitoring treatment efficacy is a large area of cancer research as it can increase the effectiveness of therapy regimens. Diffusion weighted Magnetic Resonance imaging (DWI), allows assessment of tissue microstructure without exogenous contrast agents. In this thesis, two different DWI techniques were used to acquire data from acute myeloid leukemia cells undergoing apoptosis, and data was fitted to an analytical model of re- stricted diffusion. Results indicated a decrease in average restriction size from 6.4 to 2.7μm, and an increase in the restricted diffusion coefficient from 0.17 to 0.82μm^2/ms in untreated versus treated cells. The free diffusion coefficient was constant indicating changes in restrictions, rather than any intrinsic changes in the intra-cellular or extra- cellular fluid. This combination of techniques has the potential for use in preclinical and clinical settings as it demonstrates that apoptotic changes may be measured consistently.

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30

Cheng, Chieh-Fang, and 鄭傑方. "Design of Tracking System with Respiratory Flow Measurement in High Intensity Focused Ultrasound Liver Tumor Treatment." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19575422820089353008.

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Анотація:

碩士
國立臺灣大學
電機工程學研究所
96
In the research of treating tumors, High Intensity Focused Ultrasound (HIFU) is one of the popular treatment methods in the recent years. The treatment in the moving tumor is always a serious problem. A number of methods can solve this in the radiotherapy. Comparing Real-Time Radiotherapy Tracking System (RTRT), there is not a nicer HIFU tracking treatment system so NTU MRI Guided HIFU Tracking System was developed before. A Magnetic Resonance Imaging (MRI) system guides HIFU in this system. In order to solve the delay time produced in the liver position determination system, the neural network is a predictor. The predicted position is used to control the position of the ultrasound transducer. Some tracking errors always exist in NTU MRI Guided HIFU Tracking System and therefore the performance is not good enough. It is the reason to improve HIFU tracking system. In order to get a better performance, a respiration signal measurement system replaced MRI system and a mapping system replaced the liver position determination system. The mapping system is used to transform the respiration signal into the liver position. The system is called NTU Respiration Signal Based HIFU Tracking System. A higher sampling rate of getting liver positions is in this system. The tracking error of this system is lower than the tracking error of NTU MRI Guided HIFU Tracking System. The performance of NTU Respiration Signal Based HIFU Tracking System is also better. Some comparisons verify the new design can bring the improvement in the performance of tracking.

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31

Cheng, Chieh-Fang. "Design of Tracking System with Respiratory Flow Measurement in High Intensity Focused Ultrasound Liver Tumor Treatment." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2907200811524500.

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32

Markus, Rohrschneider, Gerik Scheuermann, Stefan Höhme, and Dirk Drasdo. "Shape Characterization of Extracted and Simulated Tumor Samples using Topological and Geometric Measures." 2007. https://ul.qucosa.de/id/qucosa%3A31954.

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The prognosis of cancer patients suffering from solid tumors significantly depends on the developmental stage of the tumor. For cervix carcinoma the prognosis is better for compact shapes than for diffusive shapes since the latter may already indicate invasion, the stage in tumor progression that precedes the formation of metastases. In this paper, we present methods for describing and evaluating tumor objects and their surfaces based on topological and geometric properties. For geometry, statistics of the binary object's distance transform are used to evaluate the tumor's invasion front. In addition, a simple compactness measure is adapted to 3D images and presented to compare different types of tumor samples. As a topological measure, the Betti numbers are calculated of voxelized tumor objects based on a medial axis transform. We further illustrate how these geometric and topological properties can be used for a quantitative comparison of histological material and single-cell-based tumor growth simulations.

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33

von, Neubeck Cläre. "Radiobiological experiments for carbon ion prostate cancer therapy: Interplay of normal and tumor cells in co-culture and measurement of the oxygen enhancement ratio." Phd thesis, 2009. https://tuprints.ulb.tu-darmstadt.de/1973/1/Cl%C3%A4re_PhD.pdf.

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Co-culture models are helpful to examine cell to cell interactions in vitro and to assess the cross-communication between two particular cell populations. Co-culture systems partially reflect the complex in vivo situation: in this study an in vitro co-culture model of prostate cancer cells {(Dunning R-3327-AT-1)} and small intestine cells {(intestinal epithelium cell line 6)} of the rat was established to simulate the carbon ion treatment of prostate cancer patient at GSI. Both cell lines were characterized in mono-cultures for their radio-biological response against 250 kVp x-rays and carbon ions of 270 MeV/u, 100 MeV/u, and 11.4 MeV/u, respectively. The parameters of the linear quadratic model, alpha and beta, for cell survival curves were determined as well as the relative biological effectiveness {(RBE)}. The measured RBE values were compared to calculations of the local effect model and were in agreement with the calculations. The RBEalpha increased stronger for the more radio-resistant prostate cancer cell line than for the epithelium cell line. The survival of unirradiated and irradiated cells from co-culture {(250 kVp x-rays, 100 MeV/u and 11.4 MeV/u carbon ions)} was compared to mono-cultures under the same conditions. The measured effects were attributed to irradiation independent as well as irradiation dependent factors. To study these effects, the inflammatory cytokines TGFbeta, TNFalpha, and IL-2 were analyzed, but their secretion was independent of radiation. To study the problem of hypoxic cells in tumor treatment a hypoxia chamber was developed in which cells were grown under defined oxygen status. Prostate cancer cells were irradiated with 250 kVp x-rays and carbon ions with a mean LET of 100 keV/µm under oxic and hypoxic conditions. The oxygen enhancement ratios for 10\% survival were found to be OER 2.35 for x-rays and 1.5 for carbon ions. The results of the co-culture model and the experiments under defined oxygen status are discussed in relation to ongoing prostate cancer therapy.

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34

Sureshkumar, Ahthavan R. "Investigation into the Origin and Nature of Variability in Quantitative Measurements of Tumour Blood Flow with Contrast-enhanced Ultrasound." Thesis, 2012. http://hdl.handle.net/1807/33547.

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Microbubble ultrasound (US) contrast agents have been used to monitor the progression of anti-angiogenic chemotherapies. However, US backscatter measurements used in contrast imaging are inherently variable, given the presence of many microbubbles of random position and size. A model was developed to investigate the influence of US scanner and microbubble characteristics on these variable measurements. The Coefficient of Variation was used to measure variability. It was found that an optimum excitation frequency exists that minimizes this variability. In the case of DefinityTM, a 2.25 MHz centre-frequency pulse yielded a less variable measurement than at 5 MHz. Conversely, decreasing microbubbble concentration was found to significantly increase variability. Evidence suggests that microbubbles are no longer Rayleigh scatterers at sufficient low concentrations. Post-processing was found to aid in reducing measurement variability by averaging samples where microbubble positions are uncorrelated. As well, reduction can be achieved by averaging about a region-of-interest of uniform perfusion.

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35

Hochhauser, Daniel, Timothy Meyer, Victoria J. Spanswick, Jenny Wu, Peter H. Clingen, Paul M. Loadman, Margaret Cobb, et al. "Phase 1 Study Of A Sequence Selective Minor Groove DNA Binding Agent (SJG-136) with Pharmacokinetic and Pharmacodynamic Measurements in Patients with Advanced Solid Tumours." 2009. http://hdl.handle.net/10454/4564.

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PURPOSE: This phase I dose-escalation study was undertaken to establish the maximum tolerated dose of the sequence-selective minor groove DNA binding agent SJG-136 in patients with advanced solid tumors. The study also investigated antitumor activity and provided pharmacokinetic and pharmacodynamic data. EXPERIMENTAL DESIGN: Sixteen patients were assigned sequentially to escalating doses of SJG-136 (15-240 microg/m(2)) given as a 10-minute i.v. infusion every 21 days. The dose was subsequently reduced in incremental steps to 45 microg/m(2) due to unexpected toxicity. RESULTS: The maximum tolerated dose of SJG-136 was 45 microg/m(2). The main drug-related adverse event was vascular leak syndrome (VLS) characterized by hypoalbuminemia, pleural effusions, ascites, and peripheral edema. Other unexpected adverse events included elevated liver function tests and fatigue. The VLS and liver toxicity had delayed onset and increased in severity with subsequent cycles. Disease stabilization was achieved for >6 weeks in 10 patients; in 2 patients this was maintained for >12 weeks. There was no evidence of DNA interstrand cross-linking in human blood lymphocytes with the use of the comet assay. Evidence of DNA interaction in lymphocytes and tumor cells was shown through a sensitive gamma-H2AX assay. SJG-136 had linear pharmacokinetics across the dose range tested. CONCLUSIONS: SJG-136 was associated with dose-limiting VLS and hepatotoxicity when administered by short injection every 21 days. DNA damage was noted, at all dose levels studied, in circulating lymphocytes. The etiology of the observed toxicities is unclear and is the subject of further preclinical research. Alternative clinical dosing strategies are being evaluated.

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36

Pratt, Michelle Sherman. "Comparison of linear, bi-dimensional, and volumetric measurements in evaluating tumor response of hepatocellular carcinoma lesions in the arterial and portal venous phases on MRI." Thesis, 2015. https://hdl.handle.net/2144/15617.

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Анотація:

There are unmet needs in evaluating treatment response of hepatocellular carcinoma in research protocols. Early predictors, such as imaging biomarkers, could allow for earlier judgment of treatment effect. Currently RECIST is the most widely accepted criterion in clinical trials. A modified RECIST (mRECIST) criterion was developed to take into account the unique imaging characteristics of HCC lesions. Much discussion has occurred regarding linear measurements and their appropriateness for evaluating change in tumor burden over time. The simplicity of currently accepted criteria differs with the increasing sophistication of imaging techniques. Tumor volume change on 3D imaging can provide insight into actual action of treatment rather than an estimate of action as shown by linear and bi-dimensional measurements. It was the aim of this study to determine whether linear, bi-dimensional, and volumetric percent changes of HCC lesions, in both the arterial and portal venous phases, are significantly comparable. 27 HCC lesions (identified on 25 subjects) were measured at two timepoints by each method on 3D GRE MRI scans in both phases. Percent change was calculated per lesion for each measurement type in both the arterial and portal venous phases. Signed rank tests, paired t tests, and comparison of change tests were run to evaluate the data. Significant differences between the percent changes of linear measurements versus volumetric measurements were observed using a Wilcoxon signed-rank test which showed p = 0.0000. A simple correlation assessment showed positive correlations for all measurements, with the lowest being correlations 0.8679 for the arterial linear percent change versus the arterial volumetric percent change and 0.8434 for the portal venous linear percent change versus the portal venous volumetric percent change. Differences between percent changes of linear versus bi-dimensional measurements and bi-dimensional versus volumetric measurements were significant as well (Linear versus bi-dimensional p = 0.0001, bi-dimensional versus volumetric p = 0.0004). To conclude, the differences in the percent changes when comparing the measurement types are statistically significant, particularly when comparing linear and volumetric measurements. Establishing a reproducible volumetric criterion could lead to improvements in the implementation of clinical trials.

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37

Neubeck, Cläre von [Verfasser]. "Radiobiological experiments for carbon ion prostate cancer therapy : interplay of normal and tumor cells in co-culture and measurement of the oxygen enhancement ratio / von Cläre von Neubeck." 2009. http://d-nb.info/999116827/34.

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38

Mangelsdorf, Johanna. "Vergleich unidimensionaler, bidimensionaler und volumetrischer Messverfahren unter Anwendung eines 64-Zeilen-Mehrschicht-CTs am Beispiel von Bronchialkarzinomen und pulmonalen Metastasen." Doctoral thesis, 2009. http://hdl.handle.net/11858/00-1735-0000-0006-AF5E-E.

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39

Häring, Steffi. "Die organ- und visuserhaltende Brachytherapie kindlicher intraorbitaler Tumoren ein Vergleich der Dosierung mit den Richtlinien des Reports 58 der International Commission on Radiation Units and Measurements /." 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014188954&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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40

Blair, Alexandra. "Addressing gaps in colorectal cancer screening in Canada : multilevel determinants of screening, pathways to screening inequalities, and program evaluation." Thèse, 2018. http://hdl.handle.net/1866/22576.

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