title: Late toxicity and quality of life after definitive treatment of prostate cancer: redefining optimal rectal sparing constraints for intensity-modulated radiation therapy.
abstract: The objective of this study was to assess late toxicity and quality of life (QOL) for patients receiving definitive intensity-modulated radiotherapy (IMRT) and image-guided radiation therapy (IGRT) with regard to normal tissue sparing objectives. Three hundred and seventy-two consecutive men treated with definitive IMRT for prostate adenocarcinoma. Toxicity was graded by CTC v3.0 genitourinary (GU) and gastrointestinal (GI) toxicity at each follow-up visit. Patient-reported QOL (EPIC-26) was prospectively collected for a subset of men. Dosimetric data for bladder and rectum were compared to toxicity and QOL global domain scores, specifically analyzing outcomes for men who met ideal rectal constraints (V70 <10%, V65 <20%, V40 <40%). The median age and prescription dose was 69 years and 76 Gy, respectively. Median follow-up was 47 months. At 4 years, freedom from Grade 2 (FFG2) GI toxicity was 92% and FFG2 GU toxicity was 76%. On univariate analysis, current smoking, larger bladder volume, and higher RT dose were associated with decreased FFG2 GU toxicity, while use of anticoagulation, increasing age, and not meeting ideal rectal constraints were associated with decreased FFG2 GI toxicity (all P ≤ 0.05). Bowel QOL remained stable over the 2-year follow-up period and was higher for patients who met ideal rectal constraints (P = 0.05). IMRT with IGRT is associated with low rates of severe toxicity and a high GI and GU QOL. The use of strict rectal constraints can further improve GI QOL and reduce GI toxicity.
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Sravana K
authors.initials: SK
authors.lastname: Chennupati
authors.forename: Charles A
authors.initials: CA
authors.lastname: Pelizzari
authors.forename: Rangesh
authors.initials: R
authors.lastname: Kunnavakkam
authors.forename: Stanley L
authors.initials: SL
authors.lastname: Liauw
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011788:Quality of Life; D011832:Radiation Injuries / Q000453:epidemiology*; D061089:Radiotherapy, Image-Guided; D050397:Radiotherapy, Intensity-Modulated; D012007:Rectum / Q000473:pathology / Q000528:radiation effects; D014549:Urinary Incontinence / Q000453:epidemiology*; D014566:Urogenital System / Q000503:physiopathology / Q000528:radiation effects
keywords: Dose-volume histogram; prostate cancer; quality of life; radiation therapy