ESTRO 2021 Abstract Book

S1097

ESTRO 2021

Conclusion a high proportion of PSMA-positive patients had an actually delivered RT plan different from the intended SRT plan. PSMA-PET negativity at first BCR following RP strongly relates to better prognosis compared with the cluster of PSMA-positive patients. PO-1336 Salvage HDR brachytherapy for localised recurrent prostate cancer after primary irradiation M. Stankiewicz 1 , P. Wojcieszek 1 , P. Lelek 1 , T. Krzysztofiak 1 , S. Kellas-Sleczka 1 1 Maria Sklodowska-Curie National Research Institute of Oncology, Brachytherapy Department, Gliwice, Poland Purpose or Objective High-dose-rate brachytherapy (HDR-BT) is one of the most efficient salvage approaches in recurrent prostate cancer. The aim of this research is to present updated results of salvage high-dose-rate brachytherapy in patients with this disease. Materials and Methods A retrospective analysis of patients with follow up of at least 6 months treated with salvage HDR-BT between April 2008 and February 2018. All patients were diagnosed with localised, biopsy-confirmed prostate cancer relapse after primary irradiation. Patients were treated with interstitial implants in three fractions of 10 Gy or two fractions of 13 Gy every two weeks. All implantations were performed under epidural or general anaesthesia. Biochemical recurrence was defined according to Phoenix criteria. Results One hundred fifty-eight patients were enrolled in this analysis. Median age was 70 years (range: 42 – 81 years). Median follow-up was 55.5 months (range: 7 – 141 months). Median PSA max at recurrence was 2.7 ng/mL (range: 0.04 – 20 ng/mL). Gleason score (GS) 6 was diagnosed in 17% of patients, 7 – in 26%, ≥8 – in 12%, in 45%