<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Biological Dose Accumulation in Image-guided Radiotherapy"^^ . "Dose accumulation (DA), the computation of the total delivered 3D dose distribution Da\r\nof a fractionated radiotherapy treatment using daily patient imaging, is getting established\r\nin clinical practice. Although the aim is to estimate the achieved biological outcome of the\r\ntreatment, the principles of biological effect estimation are currently not followed consistently\r\nin the process. In this thesis, the biological effect accumulation approach and total\r\nbiological dose (bEQD) were derived as a biologically consistent DA workflow. Clinical\r\nrelevance of bEQD and its dependence on individual workflow aspects were investigated\r\nin data from three patient cohorts. It was found that Da systematically underestimates\r\nthe obtained biological effect, which can be avoided by the use of bEQD. Results showed\r\nthat this is strongest for late-responding organs at risk (OAR) with low �=� values in\r\ndose gradient regions around the target that are prone to organ motion. bEQD to Da\r\ndeviations occurred locally, in so-called hotspots, showing individual cases of high difference\r\nmagnitude but only small statistical impact. Hotspots of bEQD - Da deviation\r\naround 4 Gy in bladder and rectum were found in patients treated for prostate carcinoma.\r\nHypofractionation increased these deviations strongly up to 8 Gy and also showed clinically\r\nrelevant deviations in dose-volume analysis. Dose-response correlation in standard\r\nfractionation showed only little impact on the DA approaches. Workflow uncertainties are\r\ndominated by those from deformable image registration, which are in the same range as\r\nthe difference between bEQD and Da. bEQD should be considered in the application of\r\ntreatment adaptation, especially to avoid damage to OARs in individual cases."^^ . "2021" . . . . . . . "Nina Isabelle"^^ . "Niebuhr"^^ . "Nina Isabelle Niebuhr"^^ . . . . . . "Biological Dose Accumulation in Image-guided Radiotherapy (PDF)"^^ . . . "Dissertation_NinaNiebuhr2019.pdf"^^ . . . "Biological Dose Accumulation in Image-guided Radiotherapy (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #27620 \n\nBiological Dose Accumulation in Image-guided Radiotherapy\n\n" . "text/html" . . . "500 Naturwissenschaften und Mathematik"@de . "500 Natural sciences and mathematics"@en . . . "530 Physik"@de . "530 Physics"@en . . . "610 Medizin"@de . "610 Medical sciences Medicine"@en . .