3264 - Urinary Organs at Risk for Prostate Cancer External Beam Radiation Therapy: Contouring Guidelines
Presenter(s)
J. Le Guevelou1, T. Zilli2, L. Ferretti3, L. Beuzit4, O. G. De Hertogh5, S. Palumbo6, M. Jolicoeur7, G. Crehange8, T. Derashodian7, R. De Crevoisier9, O. Chapet10, M. Terlizzi11, S. Supiot12, C. Salembier13, and P. Sargos14; 1Laboratoire du traitement de l'image et du signal, université de Rennes, Rennes, France, 2IOSI - Oncology Institute of Southern Switzerland, Bellinzona, Switzerland, 3Department of urology, MSP Bordeaux Bagatelle, talence, France, 4CHU Rennes, Rennes, France, 5CHPLT, Verviers, Belgium, 6Hopital Jolimont, La Louviere, Belgium, 7Charles LeMoyne Hospital, Longueuil, QC, Canada, 8Institut Curie, Paris, France, 9CRLCC Eugène Marquis, Rennes, France, 10Centre Hospitalier Lyon Sud, Pierre Benite, France, 11Institut Gustave Roussy, Villejuif, France, 12Institut de Cancérologie de l'Ouest René Gauducheau, Saint-Herblain, France, 13Europe Hospital Brussels, Brussels, Belgium, 14CRLCC Institut Bergonie, Bordeaux, Aquitaine, France
Purpose/Objective(s):
The occurrence of genitourinary (GU) toxicity is a common adverse event observed after external beam radiation therapy (EBRT) for prostate cancer (PCa). Recent findings suggest that the dose delivered to specific urinary organs at risk (OARs) such as the ureters, bladder trigone, and urethra is involved in the development of GU toxicity.Materials/Methods:
A multidisciplinary task force including 3 radiation oncologists, a uroradiologist, and a urologist was created in 2022. First, OARs potentially involved in GU toxicity were identified and discussed. A literature review was performed, addressing several questions relative to urinary OARs: anatomic and radiological definition, radiation-induced injury, and dose-volume parameters. Second, results were presented and discussed with a panel of radiation oncologists and members of the "Francophone Group of Urological Radiation Therapy." Thereafter, the "Francophone Group of Urological Radiation Therapy" experts were asked to answer a dedicated questionnaire, including 35 questions on the controversial issues related to the delineation of urinary OARs.Results:
The following structures were identified as critical for PCa EBRT: ureters, bladder, bladder neck, bladder trigone, urethra (intraprostatic, membranous, and spongious), striated sphincter, and postenucleation or posttransurethral resection of the prostate cavity. A consensus was obtained for 32 out of 35 items.Conclusion:
This consensus highlights contemporary urinary structures in both the upper and lower urinary tract to be considered for EBRT treatment planning of PCa. The current recommendations also propose a standardized definition of urinary OARs for both daily practice and future clinical trials.