Risk factors for bladder adverse events following radiotherapy for localised and locally advanced prostate cancer in Gabon

Abstract Background: The aim of this study was to identify potential risk factors for acute and late genitourinary toxicities and to determine, using a logistic regression model, which of these factors are also significant and robust predictors of these toxicities. Methods: We conducted a retrospective study by analysing the patient records and their treatment plans from 2013 to 2021. In total, a cohort of 46 patients with clinically staged cT1c-T4N0-1M0 prostate adenocarcinoma was treated with three-dimensional conformal radiotherapy (3D-CRT) with doses ranging from 66 to 80 Gy. Post-radiotherapy genitourinary toxicities were classified and graded according to the Common Terminology Criteria for Adverse Events (CTCAE v4.0). Results: Median follow-up was 57·5 months (range: 39 – 88 months). In univariable analysis, patient age ( p = 0·040), the prostate volume ( p = 0·0423), the clinical prostate volume irradiated at the prescribed dose ( p = 0·029) and the volume of the bladder receiving doses varying from 60 to 70 Gy were correlated with acute GU toxicities. Arterial hypertension (p = 0·022), some pre-existing urinary symptoms, a history of catheterisation ( p = 0·044) and acute genitourinary toxicity (p = 0.009) were linked to late genitourinary toxicities. The logistic regression model found that the prostate volume ( p = 0·0423) and the clinical prostate volume irradiated at the prescribed dose ( p = 0·029) were predictive of acute GU toxicity. Hypertension ( p = 0·039) and acute toxicities were predictive of late GU toxicity. Conclusion: The results of our study showed that it is essential to identify patients at risk of toxicities from the start of radiotherapy and to offer more proactive monitoring and management.