Relation between local cure and dose-time-volume factors in interstitial implants.
The dose and volume data of 119 patients treated with radium or iridium-192 implants for cancer of the tongue, bladder or perineum are presented. The computer dosimetry system used in the Antoni van Leeuwenhoek Hospital permitted analysis of data regarding treated volume, dose variation inside the treated volume, patterns of geographical defects and their impact on the result of treatment. Dose was expressed in a number of ways, including prescribed (reference) and average dose and the CRE (Cumulative Radiation Effect) level attained. The CRE value included a time correction and a volume correction. The average dose proved to be the best predictor of local result in case of tongue and perineal implants. Great care is needed in case of tongue carcinoma to avoid a geographical miss by an inadequate treatment volume or geometric defects. The hypothesis that a dose reduction factor is necessary, in case of a high dose rate, could not be validated.
D001918:Brachytherapy; D005260:Female; D006801:Humans; D007495:Iridium; D008297:Male; D008875:Middle Aged; D010502:Perineum; D011868:Radioisotopes; D011879:Radiotherapy Dosage; D011883:Radium; D013997:Time Factors; D014062:Tongue Neoplasms / Q000532:radiotherapy*; D001749:Urinary Bladder Neoplasms / Q000532:radiotherapy*
D011868:Radioisotopes; D007495:Iridium; D011883:Radium