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.
Clinical and translational radiation oncology. 2024 Dec 30*** epublish ***
Jennifer Le Guévelou, Paul Sargos, Piet Ost, Filippo Alongi, Stefano Arcangeli, Alejandro Berlin, Pierre Blanchard, Anna Bruynzeel, Olivier Chapet, Alan Dal Pra, Robert T Dess, Matthias Guckenberger, Andrew Loblaw, Amar U Kishan, Barbara Jereczek-Fossa, David Pasquier, Mohamed Shelan, Shankar Siva, Alison C Tree, Costantinos Zamboglou, Stephane Supiot, Vedang Murthy, Thomas Zilli
Department of Clinical Research, Centre Eugène Marquis, Rennes, France., Department of Radiation Oncology, Institut Bergonié, Bordeaux, France., Department of Human Structure and Repair, Ghent University, Ghent, Belgium., Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, Italy., Radiation Oncology Department, Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy., Department of Radiation Oncology, Princess Margaret Cancer Center, University Health Network and University of Toronto, Toronto, Ontario, Canada., Department of Radiation Oncology, Gustave Roussy, Université Paris-Saclay, Villejuif, France., Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Radiation Oncology, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands., Department of Radiation Oncology, Hôpital Lyon Sud, Lyon, France., Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Health Systems, Miami, FL, USA., Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA., Department of Radiation Oncology, University Hospital Zürich, University of Zürich, Zürich, Switzerland., Institute of Healthcare Policy and Management, Department of Radiation Oncology, Ontario Institute of Cancer Research, University of Toronto, Toronto, Ontario, Canada., Department of Radiation Oncology, University of California, Los Angeles, CA, USA., Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy., Department of Radiation Oncology, Centre Oscar Lambret, Lille, France., Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland., Division of Radiation Oncology and Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Center, University of Melbourne, Melbourne, Victoria, Australia., Department of Radiation Oncology, The Royal Marsden NHS Foundation Trust, Sutton, UK., German Oncology Center, European University of Cyprus, 1 Nikis Avenue, 4108, Agios Athanasios, Cyprus., Department of Radiation Oncology, University Hospital Freiburg, Robert-Koch-Straße 3, 79106, Freiburg, Germany., Department of Radiation Oncology, Oncology Institute of Southern Switzerland, EOC, Bellinzona, Switzerland.