ESTRO 2024 - Abstract Book

S2526

Clinical - Urology

ESTRO 2024

The study was approved by our local ethics committee. Our institutional database was reviewed from 2010 to 2022. Inclusion criteria were patients having received sRT after CT. Exclusion criteria was a follow up less than 3 months and other focal therapies other than CT. Clinical, pathological and salvage treatment characteristics were recorded. Primary endpoint of the study was toxicity evaluation. Secondary endpoints were OS (Overall Survival), PFS (Progression Free Survival) and bRFS (biochemical relapse free survival). Mean, median, ranges and Kaplan-Meier method for survival were used. Toxicity was recorded with RTOG scale. Data was analyzed with SPSS v25.

Results:

From 2013 to 2021, 15 patients with initial staging of localized PC that received primary CT and posterior sRT were included. Median age at diagnosis of PC was 73 years (54 – 79). 33.3% (5) patients were low risk, 40% (6) intermediate risk and 26.4% (4) by NCCN risk stratification groups. Mean initial PSA was 7.49ng/mL (5.2 – 15.76). Initial ISUP grade was 1 in 33.3% (5), 2 in 26.7% (4), 3 in 26.7% (4) and 4 in 13.3% (2). Median time to progression and sRT was 47 months (7-186). Mean PSA at relapse was 4.86ng/mL (0.36 – 11.25). All patients except one had and MRI and prostate biopsy pre sRT, with ISUP at relapse unknown or ungradable in 20% (3), 2 in in 33.3% (5), 3 in 6.7% (1), 4 in 13.3% (2) and 5 in 26.7% (4). The upgrade in ISUP and pathological findings in MRI guided treatment choice. Median dose to prostate was 74Gy (70-78). 46.7% (7) were hypofractionated (2.5Gy/fr). In 53.3% (8) pelvis was treated. 60% (9) were planned in 3D conformal RT and 40% (6) with intensity modulated radiotherapy (IMRT). 80% (12) received hormonal treatment, with a range between 6 to 24 months depending on ISUP stage at relapse.

Median follow-up after sRT was 52 months (3-101). 33.3% (5) of patients had GU G2 acute toxicity. Chronic G2 GU toxicity was 13% (2), and G3 13% (2). Chronic GI G2 toxicity was 6.7% (1).

Mean PFS after sRT was 82.7 months (65.3-100) with only 1 local relapse and 1 distant (M1a) progression, both with biochemical progression. Median OS and CSS were not reached, with 4 patients dying during follow up, 1 from systemic progression and the other 3 from other causes.

Conclusion:

Our monocentric series analysis showed that sRT after CT provides high rates of PFS and local control with a moderate toxicity profile which demands careful evaluation by the radiation oncologist and individualization of treatment.

Keywords: salvage, radiotherapy, criotherapy

References:

1. Jung JH, Risk MC, Goldfarb R, Reddy B, Coles B, Dahm P. Primary cryotherapy for localised or locally advanced prostate cancer. Cochrane Database Syst Rev. 2018 May 30;5(5):CD005010.