ESTRO 2024 - Abstract Book

S2294

Clinical - Urology

ESTRO 2024

two (0.3%) had DM only. Patients who received ADT had significantly higher pre-treatment PSA levels and clinical tumor stage. Younger age [HR: 0.35 (95% CI, 0.14 –0.86);p =0.02], positive core biopsy (PCB) ≥50% [HR: 7.39 (95% CI, 2.30 – 24.52); p=0.001], 78/86 only treatment [HR: 3.39 (95% CI, 1.46 – 7.88); p=0.005], and the absence of ADT [HR: 4.64 (95%CI, 1.28 – 7.21);p=0.002] were all independent predictors of poor FFBF in multivariate analysis, whereas patients with PCB <50% who were also given ADT had better PCSS. The 8-year FFBF and PCSS rates for FIR and UIR patients were 94.4% and 89.7% (p = 0.07), 100% and 98.8% (p=0.16), respectively. In the FIR cohort, there was no significant difference in FFBF (88.4%, 100%, 100%, p > 0.05) or PCSS (100%, 100%, 100%, p > 0.05) between treatment groups ADT patients had significantly higher FFBF (HR=3.06 (95% CI, 1.29 – 7.52); p=0.01) and PCSS (HR=8.06; (95% CI, 1.54 – 42.23); p = 0.01) in UIR patients. However, dose escalation using the SIB technique has no effect on FFBF or PCSS in both groups. There was no significant difference between treatment groups in terms of acute and late Grade ≥2 genitourinary or gastrointestinal toxicity.

Conclusion:

Compared to patients treated with DE-RT alone, our data support the benefit of short-term ADT regardless of dose escalation in IR-PC patients, especially UIR patients, but not FIR patients. Due to the substantial heterogeneity of IR PC patients, additional research is necessary to identify those who may benefit from ADT and/or DE-RT.

Keywords: ADT, Prostate cancer, Radiotherapy.

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Digital Poster

Clinical Outcomes of SBRT for Oligometastatic Prostate Cancer: analysis of one hundred treatments

Elías Gomis Sellés, Óscar Muñoz Muñoz, Blas David Delgado León, Patricia Cabrera Roldán, José Luis López Guerra

University Hospital Virgen del Rocío, Radiation Oncology, Seville, Spain

Purpose/Objective:

To assess the impact of SBRT on disease control. The secondary objective is to evaluate this toxicity.

Material/Methods:

This study is a retrospective cohort analysis, involving the inclusion of patients diagnosed with oligometastatic prostate cancer who underwent SBRT (Stereotactic Body Radiotherapy) for metastases at a single medical institution. The data encompassed cases between 2017 and May 2023, and statistical analyses were conducted using the Wilcoxon test and Cox regression. In total, we examined 71 patients, accounting for a collective total of 102 metastatic lesions. The study period extended to a median follow-up of 73 months from the initial diagnosis, with a specific focus on a median follow-up of 13.3 months from the administration of SBRT.