Radiotherapy Use in Muscle-Invasive Bladder Cancer: Review of the Guidelines and Impact of Increased Awareness in Patient Referral at a Tertiary Center in Belgium.

Purpose: Pronounced underuse of radiotherapy (RT) in muscle-invasive bladder cancer (MIBC) is reported. This study aims to assess the awareness about the role of RT in different MIBC settings and see whether this has increased since 2017. Materials and Methods: We reviewed the bladder cancer guidelines of the EAU, ESMO, NCCN, NICE, and AUA/ASCO/ASTRO/SUO, focusing on the role of RT in MIBC. In 2017, we evaluated the use of RT in MIBC in Belgium. This raised awareness about the indications of RT in different MIBC settings. Here, we present a retrospective pattern of care analysis of the RT use for MIBC patients at our center from January 2012 until December 2021. Frequency of RT use, patient, disease and treatment characteristics were compared between two 5-year periods (2012-2016 and 2017-2021). Results: Review of the guidelines suggested that RT can be used as a treatment option in most MIBC settings. However, differences between guideline recommendations existed and high-level evidence was often lacking. Overall, 221 unique MIBC patients received RT at our center. RT use for MIBC was 39% higher in the second 5-year period (Between the same periods, the number of new MIBC registrations increased with 26%). The most pronounced increase, ie, 529%, was observed in the primary setting and was in parallel with patient preference becoming the main indication for RT. Participation in clinical trials seems to have had an important impact on the frequency of RT use in the adjuvant and metastatic setting. Conclusion: We provide a critical overview of the RT indications in MIBC as recommended by the international guidelines. Increased awareness about RT as a treatment option in MIBC seems to have an impact on the treatment choice in clinical practice, as was observed in our tertiary center.