Carla Sini1, Barbara Noris Chiorda2, Pietro Gabriele3, Giuseppe Sanguineti4, Sara Morlino5, Fabio Badenchini6, Domenico Cante7, Viviana Carillo8, Marcella Gaetano8, Tommaso Giandini9, Valeria Landoni10, Angelo Maggio11, Lucia Perna1, Edoardo Petrucci12, Vincenzo Sacco2, Riccardo Valdagni13, Tiziana Rancati6, Claudio Fiorino14, Cesare Cozzarini2. 1. Medical Physics, San Raffaele Scientific Institute, Milano, Italy. 2. Radiotherapy, San Raffaele Scientific Institute, Milano, Italy. 3. Radiotherapy Department, Candiolo Cancer Institute - FPO, IRCCS, Italy. 4. Department of Radiotherapy, Regina Elena National Cancer Institute, Rome, Italy. 5. Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy. 6. Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy. 7. Radiotherapy, ASL TO4 Ospedale di Ivrea, Italy. 8. Radiotherapy, Centro AKTIS Diagnostica e terapia, Napoli, Italy. 9. Medical Physics, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy. 10. Department of Physics, Regina Elena National Cancer Institute, Rome, Italy. 11. Medical Physics Department, Candiolo Cancer Institute - FPO, IRCCS, Italy. 12. Medical Physics, ASL TO4, Ospedale di Ivrea, Italy. 13. Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy; Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy; UNIV Hematology and Hemato-Oncology, Università degli Studi di Milano, Italy. 14. Medical Physics, San Raffaele Scientific Institute, Milano, Italy. Electronic address: fiorino.claudio@hsr.it.
Abstract
BACKGROUND AND PURPOSE: Intestinal toxicity is commonly experienced during whole-pelvis intensity-modulated radiotherapy (WPRT) for prostate cancer. The aim of the current study was to assess bowel dose-volume relationships for acute patient-reported intestinal symptoms of patients treated with WPRT for prostate cancer. MATERIALS AND METHODS: Complete data of 206 patients were available; the median dose to pelvic nodes was 51.8Gy (range 50.4-54.4, 1.7-2Gy/fr). Intestinal symptoms were assessed as changes in the Inflammatory Bowel Disease Questionnaire scores relative to the Bowel Domain (IBDQ-B) between baseline and radiotherapy mid-point/end. The 25th percentiles of the most severe worsening from baseline (ΔIBDQ-B) were set as end-points. The impact of bowel loops and sigmoid colon dose-volume/surface parameters as well as selected clinical parameters were investigated using multivariate logistic regression. RESULTS: Analyses were focused on the four questions showing a median ΔIBDQ-B>0. No dose volume/surface parameters were predictive, other than ΔIBDQ5≥3 (loose stools): when grouping patients according to bowel DVHs (high risk: V20>470cc, V30>245cc, V42>110cc; low risk: all the remaining patients), a two-variable model including high-risk DVH-shape (OR: 9.3) and age (protective, OR: 0.94) was assessed. The model showed good calibration (slope: 1.003, R2=0.92) and was found to be robust after bootstrap-based internal validation. CONCLUSIONS: Constraining the bowel loops may reduce the risk of loose stools. The risk is higher for younger patients.
BACKGROUND AND PURPOSE: Intestinal toxicity is commonly experienced during whole-pelvis intensity-modulated radiotherapy (WPRT) for prostate cancer. The aim of the current study was to assess bowel dose-volume relationships for acute patient-reported intestinal symptoms of patients treated with WPRT for prostate cancer. MATERIALS AND METHODS: Complete data of 206 patients were available; the median dose to pelvic nodes was 51.8Gy (range 50.4-54.4, 1.7-2Gy/fr). Intestinal symptoms were assessed as changes in the Inflammatory Bowel Disease Questionnaire scores relative to the Bowel Domain (IBDQ-B) between baseline and radiotherapy mid-point/end. The 25th percentiles of the most severe worsening from baseline (ΔIBDQ-B) were set as end-points. The impact of bowel loops and sigmoid colon dose-volume/surface parameters as well as selected clinical parameters were investigated using multivariate logistic regression. RESULTS: Analyses were focused on the four questions showing a median ΔIBDQ-B>0. No dose volume/surface parameters were predictive, other than ΔIBDQ5≥3 (loose stools): when grouping patients according to bowel DVHs (high risk: V20>470cc, V30>245cc, V42>110cc; low risk: all the remaining patients), a two-variable model including high-risk DVH-shape (OR: 9.3) and age (protective, OR: 0.94) was assessed. The model showed good calibration (slope: 1.003, R2=0.92) and was found to be robust after bootstrap-based internal validation. CONCLUSIONS: Constraining the bowel loops may reduce the risk of loose stools. The risk is higher for younger patients.
Authors: Ane L Appelt; Ellen M Kerkhof; Lars Nyvang; Ernst C Harderwijk; Natalie L Abbott; Mark Teo; Femke P Peters; Camilla J S Kronborg; Karen-Lise G Spindler; David Sebag-Montefiore; Corrie A M Marijnen Journal: Tech Innov Patient Support Radiat Oncol Date: 2019-10-15