Giannouli, SMilickovic, NBaltas, DLahanas, MZamboglou, NKarouzakis, KA stratified sampling method for the efficient repeated computation of dose-volume histograms (DVHs) in brachytherapy is presented as used for anatomy based brachytherapy optimization methods. The aim of the method is to reduce the number of sampling points required for the calculation of DVHs for the body and the PTV. From the DVHs are derived the quantities such as Conformity Index COIN and COIN integrals. This is achieved by using partial uniform distributed sampling points with a density in each region obtained from a survey of the gradients or the variance of the dose distribution in these regions. The shape of the sampling regions is adapted to the patient anatomy and the shape and size of the implant. For the application of this method a single preprocessing step is necessary which requires only a few seconds. Ten clinical implants were used to study the appropriate number of sampling points, given a required accuracy for quantities such as cumulative DVHs, COIN indices and COIN integrals. We found that DVHs of very large tissue volumes surrounding the PTV, and also COIN distributions, can be obtained using a factor of 5-10 times smaller the number of sampling points in comparison with uniform distributed points. (C) 2002 American Association of Physicists in Medicine.http://hdl.handle.net/123456789/1457834324240094-24052910.1118/1.1450131ISI:000174408000019engAMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICSMedical PhysicsDose-volume histogramsdensityanatomyHumanssamplingaccuracydose calculationModels, StatisticalimplantCOINarticleStratified samplinghistogramAlgorithmsRadiometryPeru tomato mosaic virusBrachytherapySoftwarebrachytherapypriority journalradiation dosealgorithmBrachytherapy dose-volume histogram computations using optimized stratified sampling methodsjournalArticle2002Ραδιολογία, Πυρηνική ιατρική και ΑπεικονιστικήRadiology, Nuclear Medicine and Imagingisi - Radiology, Nuclear Medicine & Medical Imaging covers resources on radiation research in biology and biophysics. Resources in this category focus on interventional radiology, investigative radiology, neuroradiology, radiotherapy, and oncology. Nuclear Medicine resources are concerned with the diagnostic, therapeutic, and investigative use of radionuclides. Medical Imaging resources are concerned with computerized medical imaging and graphics.Δημοσίευση σε περιοδικόPublication in journalΕπιστημονικό άρθροScientific articleΕθνικό Μετσόβιο ΠολυτεχνείοGreek Aggregator OpenArchives.gr | National Documentation Centre (EKT)other