Urethra-sparing prostate cancer radiotherapy: Current practices and future insights from an international survey

• Published in: Clinical and translational radiation oncology Vol. 51; p. 100907
• Main Authors: Guévelou, Jennifer Le, Sargos, Paul, Ost, Piet, Alongi, Filippo, Arcangeli, Stefano, Berlin, Alejandro, Blanchard, Pierre, Bruynzeel, Anna, Chapet, Olivier, Dal Pra, Alan, Dess, Robert T., Guckenberger, Matthias, Loblaw, Andrew, Kishan, Amar U., Alicja Jereczek-Fossa, Barbara, Pasquier, David, Shelan, Mohamed, Siva, Shankar, Tree, Alison C., Zamboglou, Costantinos, Supiot, Stephane, Murthy, Vedang, Zilli, Thomas
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.03.2025; Elsevier
• Subjects: Cancer; Humanities and Social Sciences; Life Sciences; Methodology; Methods and statistics; Other Statistics; Prostate cancer; Radiotherapy; SBRT; Short Communication; Statistics; Toxicity; Urethra; Urethra; Radiotherapy; Toxicity; Prostate cancer; SBRT
• ISSN: 2405-6308; 2405-6308
• DOI: 10.1016/j.ctro.2024.100907

•Use of MRI is recommended for urethra delineation.•Urethra-sparing contraindications: tumors <2mm from urethra and T4 tumors invading urinary structures.•Urethra-sparing techniques are recommended for prostate SBRT with focal boosting.•Urethra-sparing: considered for standard dose SBRT or reirradiation SBRT by >70% of experts. In prostate cancer patients, high radiation doses to the urethra have been associated with an increased risk of severe genitourinary toxicity following dose-escalated radiotherapy. Urethra-sparing techniques have emerged as a promising approach to reduce urinary toxicity. This international survey aims to evaluate current global practices in urethra-sparing and explore future directions for the implementation of this technique in external beam radiotherapy (EBRT) for prostate cancer. In April 2024, a survey consisting of 20 questions was distributed to 26 international radiation oncology experts in prostate cancer EBRT, with 23 experts participating. The survey focused on clinical scenarios which might take benefit from urethra-sparing, the definition of the urethra and urinary organs-at-risk, and urethral dose constraints. Magnetic resonance imaging with T2-weighted sequences is the preferred method for urethra contouring (83 % consensus). Based on the experts opinion, urethra-sparing should be considered for prostate cancer EBRT, regardless of pelvic irradiation, except in cases where the tumor is located within 2 mm of the urethra and/or transitional zone, or in T4 disease. Most experts would not apply specific dose constraints to the urethra for either conventional or moderate hypofractionation regimens. When delivering stereotactic body radiotherapy (SBRT), urethra-sparing with dose hotspot limitation (urethra steering) is recommended by 70 % of the experts, in particular when combined with focal boosting (91 %). Urethra dose-reduction is also the favored approach for salvage prostate reirradiation with SBRT (70 % agreement). Large variations exists regarding urethral dose constraints. Urethra-sparing is a promising technique for the mitigation of urinary toxicity in prostate cancer patients undergoing EBRT, particularly recommended for ultra-hypofractionation and reirradiation with SBRT. The lack of consensus on specific urethral dose constraints and optimal sparing techniques underscores the need for further research to standardize practices in this field.