Acute and late toxicity in prostate cancer patients treated with moderately vs ultra-hypofractionated radiotherapy.

INTRODUCTION

Prostate cancer is the most frequently diagnosed male malignancy in Colombia. While modern radiotherapy techniques allow for hypofractionated schedules due to the low alpha/beta ratio of prostate adenocarcinoma, real-world comparative data between moderate and ultra-hypofractionation in Latin American settings remain limited.

OBJECTIVE

To compare acute and early late toxicity in patients with prostate cancer treated with moderately hypofractionated radiotherapy versus those treated with ultra-hypofractionated regimen.

METHODS

A comparative historical cohort study was conducted at a Colombian oncology center between 2018 and 2025. A total of 229 patients with non-metastatic prostate cancer (T1-T4) were enrolled (MHRT: n=143; UHRT: n=86). Toxicity was graded using CTCAE criteria. Multivariable logistic regression was used to identify independent predictors of toxicity.

RESULTS

Acute toxicity was significantly higher in the MHRT group compared to the UHRT group (25.17% vs. 11.63%; p=0.013). Similarly, late toxicity was more frequent in the MHRT group (37.06% vs. 9.30%; p<0.001), with erectile dysfunction as the most common late event. Multivariable analysis showed that UHRT was independently associated with lower odds of acute toxicity (aOR 0.44; 95% CI 0.19-0.99; p=0.048).

CONCLUSION

UHRT showed a generally favorable safety profile, with trends toward lower acute and late toxicity compared to MHRT. In middle-income settings such as Colombia, UHRT may offer a practical approach to enhance treatment efficiency and patient access, while maintaining acceptable clinical outcomes.