ESTRO 2021 Abstract Book

S573

ESTRO 2021

statistically different, with 1- and 2- year OS rates of 70% and 48% (surgery), and 74% and 39% (SMART), respectively. The corresponding 1- and 2- year PFS rates were 42% and 26% (surgery), and 33% and 17% (SMART). Conclusion An increase in radical treatments for adrenal metastases was observed since 2016, which was mainly due to referrals for SMART in oligoprogressive disease. Using both surgery and SMART resulted in a total 2-year OS of 43%, despite the high proportion of unfavorable oligoprogressive disease in the latter. Low rates of acute toxicity were seen with both treatments.

PD-0744 Phase II trial of SBRT and androgen deprivation for oligometastases in prostate cancer.

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PD-0745 Outcomes & predictors of progression: SBRT for lymph node oligorecurrent prostate cancer on PSMA-PET A. Werensteijn-Honingh 1 , A. Wevers 1 , M. Peters 1 , P. Kroon 1 , M. Intven 1 , W. Eppinga 1 , I. Jürgenliemk-Schulz 1 1 University Medical Center Utrecht, Radiotherapy, Utrecht, The Netherlands Purpose or Objective To describe outcomes and identify predictors of progression for patients with lymph node oligorecurrent prostate cancer diagnosed on PSMA-PET and treated with stereotactic body radiotherapy (SBRT). Materials and Methods Patients from a prospective cohort study were included if they had 1-3 lymph node metastases diagnosed with PSMA-PET after initial treatment for primary prostate cancer and had not received hormonal therapy in the preceding 24 months. Patients were treated with 5 x 7 Gy or 3 x 10 Gy using MRI- or CBCT-guided SBRT. Acute toxicity was assessed until 3 months post-SBRT. PSA was measured pre-SBRT, after 3 months and then at the