ESTRO 2024 - Abstract Book

S2505

Clinical - Urology

ESTRO 2024

Median age was 77 years (range 62-84) and median iPSA level was 8.04 ng/ml (range 3.41-18.27). Intermediate unfavorable and high-risk PCa accounted for 33% and 67%, respectively. Patients, tumor and treatment characteristics are summarized in Table 1. With a median follow-up of 10 months (range 3-25), 4 instances of G2 GU toxicity were recorded, while no patients developed ≥G2 GI side effects. The mean IPSS increased from 6.1 at baseline (range 0-15) to 7.3 (6 range 1-19) at 3 months (p <0.039), and gradually returned at baseline levels thereafter. At the same time points, a transient worsening in the QoL (78 vs 68.9) and urinary domains (9 vs 18.6) was documented (p<0.012 and p<0.001, respectively), while bowel domains remained unchanged. In parallel, a MCIC in IPSS, urinary domains, QoL, and bowel domains was detected in 10 (33.5%), 13 (43%), 10 (33.5%), and 5 (16.5%) patients, respectively. The median ADC value at the DIL was 0.71 mm2/s (range 0.57-0.96) and increased to 0.91 mm2/s (range 0.65-1.13) and 1.02 mm2/s (range 0.82-1.35) at time 1 and at time 2, respectively (p < 0.001). Baseline median prostate volume was 38 cc (range 10-59); no significant changes were observed at time 1, while at time 2 a median decrease of 24% (range 9%-59%) was documented (p< 0.001). At last follow-up, all patients showed a radiological response and were found b-NED (19 patients ADT-free).

Conclusion:

RS irradiation of the whole prostate with urethral sparing and organ motion control was feasible and well tolerated in patients with organ-confined unfavorable PCa, paving the way for a patient-friendly and cost savings approach. Long-term data are awaited to confirm these findings.