Influence of rectal volume changes during radiotherapy for prostate cancer: A predictive model for mild-to-moderate late rectal toxicity

To assess the rectal volume changes during radiotherapy for prostate cancer, to estimate an average rectal dose distribution profile during treatment, and to correlate these parameters with mild-to-moderate late rectal toxicity.Nine patients with localized prostate cancer underwent virtual CT simulation using a six-field conformal 18-MV photon technique. During treatment, patients underwent weekly pelvic CT scans under simulation conditions....