ESTRO 2024 - Abstract Book

S2563

Clinical - Urology

ESTRO 2024

Heterogeneity between study-specific estimates was assessed using Chi-square statistics and measured with the I2 index (heterogeneity measure across studies). This systematic review followed a registered (PROSPERO CRD42023469379, Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023469379).

Results:

The PRISMA flow chart of the detailed selection process is demonstrated in Figure 1 . Overall, 160 studies were considered in the final analysis. Eleven studies considered the PT treatment only, 148 the XRT treatment only, and one study included both patients on PT and XRT. A total of 2918 and 30877 patients receiving PT and XRT were respectively included. Ten studies including patients who underwent PT investigated acute and late GI and GU toxicities. For XRT, 128 studies considered acute and late GI and GU toxicities. Between-arm comparison of summarized proportion of patients who experienced acute and late GI and GU toxicities is reported in Table 1 . Acute GI toxicity was significantly worse among patients who underwent XRT than PT, being the corresponding proportions 7% (5% to 9%) and 2% (2% to 4%). Similarly, acute GI toxicity was significantly worse among patients who underwent moderate hypofractionated XRT than PT being the corresponding proportions 9% (6% to 13%) and 2% (2% to 4%). There was no statistical evidence of between-arm difference in acute toxicity for ultra-hypo-fractionated schedules. Overall, there was no statistical evidence of between-arm difference in late toxicity. Subgroup analyses showed lower toxicity of PT than XRT for: (i) acute GI outcomes among patients who received seminal vescicles irradiation (2% and 7%, p-value 0.0288) and those who did not receive it (3% and 8%, p-value 0.0151); (ii) late GI toxicity among patients who did not receive seminal vesicles irradiation (1% and 4%, p-value 0.0199); and (iii) acute GI and GU outcomes among patients who did not receive pelvis irradiation (3% and 7%, p value 0.0134 and 6% and 15%, p-value 0.0224). Higher GU toxicity of PT than XRT was observed among patients who received pelvis irradiation (35% and 19%, p-value 0.0367). Data on five-year b-RFS experienced by patients who underwent PT or XRT were reported by only one and from 2 to 38 studies, respectively. Among the included studies none reported data on b-RFS experienced by high-risk patients underwent PT, thus the corresponding summarized findings excluded studies on high-risk XRT patients ( Table 2 ). Considering moderate hypofractionation, there was statistical evidence that PT patients had better b-RFS than those on XRT, with findings for both those on intermediate (97% vs. 90%; p < 0.0001) and low (99% vs. 96%; p = 0.0368) risk class. There was no evidence of between-arm difference five-year b-RFS among patients scheduled on ultra-hypofractionated.

Although PT patients were systematically better for the remaining secondary outcomes than those on XRT, between-arm differences were not significant.