Prediction of patient-reported bowel quality of life (QOL) after dose-escalated radiation therapy (RT) for prostate cancer by rectal dosimetry.
Published on Feb 20, 2013in Journal of Clinical Oncology32.956
· DOI :10.1200/JCO.2013.31.6_SUPPL.84
84 Background: Rectal dose-volume histogram (DVH) parameters and a consensus normal tissue complication probability (NTCP) model predict physician scored toxicity but have not been well studied for patient reported outcomes (PRO) following external beam RT for prostate cancer. Methods: PRO were prospectively collected at baseline and 12 month intervals by expanded prostate cancer index composite (EPIC) for 98 patients from 2004-2009. Linear regression modeling for bowel score at 1 and 2 years was performed using pre-treatment bowel score and DVH parameters [V80 (% of rectal volume >80 Gy), V75, V70, V50, V25, and NTCP]. Results: Median RT dose was 78 Gy with image-guidance in 81%, intensity-modulation in 72%, and pelvic RT in 11%. Rectal DVH parameters are presented in the Table. Pretreatment and 2 year PRO were available for 92% of patients. The mean pretreatment bowel summary score declined from 96.0 (sd 8.0) to 91.8 (13.5) at 2 years. Acute proctitis (grade 1-2) during RT was associated with a decline ...