ESTRO 2024 - Abstract Book

S2618

Clinical - Urology

ESTRO 2024

Medical records of patients with non metastatic, prostate cancer who have undergone RP in our centre and those who were referred for post operative (post-op) management at our centre after RP between 2013 to 2023 were analysed. Patients who did not follow up after surgery were excluded. If post-op PSA recorded between 6-12 weeks was above 0.1 then adjuvant RT (ART) was offered. If PSA was above 0.1 ng/mL after being undetectable during surveillance then early SRT was offered, before PSA crossed 0.2 ng/mL. If they were referred late with elevated PSA, then they were offered SRT. Radiotherapy doses ranged between 55 - 60 Gy in 20 fractions over 4 weeks with tomotherapy or volumetric arc radiation. Androgen deprivation therapy (ADT) was added on the basis of high PSA values or gross residual disease. The disease outcomes and patterns of failure have been analysed.

Results:

A total of 172 patients met the criteria for inclusion into this audit. 13 patients who did not follow up after RP were excluded from the audit. The median age of the patients was 66 years. Preoperatively 94 patients (54.7%) and 73 patients (42.4%) met the criteria for high risk and intermediate risk, respectively. 4 patients could not be assigned a risk group due to insufficient data. Postoperative histopathology showed that the majority were pathologically high risk with 56 (32.7%) patients with pT3a, 32 (18.6%) patients with pT3b and 2 (1.1%) patients with pT4. 10 patients had pathologically involved nodes while 92 (53.4%) patients had involved margins. The post-op PSA was available in 117 patients with a median of 0.04 ng/ml. 31 (26.5%) patients had PSA higher than 0.1ng/ml with 20 of these above 0.2ng/ml and were offered adjuvant radiation. 55 patients (31.9%) did not have post-op PSA recorded as defined above. The first PSA of this cohort was recorded at a median time of 4.2 months post surgery with a median of 0.14 ng/mL with 20 patients having a PSA above 0.2ng/mL. 110 patients received radiotherapy post RP with 93 patients receiving SRT while 17 patients received ART. The median gap between surgery and SRT was 11.1 months (2.7 - 110.8 months). The median pre-RT PSA at treatment start was 0.33 ng/ml. 26 patients(27.9%) received early SRT before PSA crossed 0.2 ng/mL with the rest receiving SRT. 62 (36%) patients have continued to be on PSA surveillance alone post surgery with a median follow-up of 24.5 months and have not yet reached the threshold for offering eSRT.

There were 3 patients with local failure, 2 patients with nodal failure and 3 patients with distant metastasis. 1 patient with biochemical progression was not imaged for restaging.

Conclusion:

PSA based early SRT is feasible and has good biochemical control with prompt institution of radiation therapy at a low threshold level. However, delayed initiation SRT leads to worse outcomes.

Keywords: Prostate, Radiotherapy