Long-term results with custom-linked iodine-125 seeds and real-time brachytherapy in low- and intermediate-risk prostate cancer

Jose Luis Guinot; Juan Casanova; Victor Gonzalez-Perez; Miguel Angel Santos; Victor De Los Dolores; Maria Isabel Tortajada; Carmen Guardino; Vicente Crispin; Jose Rubio-Briones; Leoncio Arribas

doi:10.5114/jcb.2022.116150

Long-term results with custom-linked iodine-125 seeds and real-time brachytherapy in low- and intermediate-risk prostate cancer

J Contemp Brachytherapy. 2022 Jun;14(3):215-221. doi: 10.5114/jcb.2022.116150. Epub 2022 May 12.

Affiliations

¹ Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia (I.V.O.) Valencia, Spain.
² Department of Urology, Fundacion Instituto Valenciano de Oncologia (I.V.O.) Valencia, Spain.
³ Department of Radiation Physics, Fundacion Instituto Valenciano de Oncologia (I.V.O.) Valencia, Spain.

Abstract

Purpose: Brachytherapy (BT) with iodine-125 (¹²⁵I) seeds is effective in low- and intermediate-risk prostate carcinoma, with fewer side effects compared to other techniques, but relapses increase in long-term. In the present paper, 10-year biochemical relapse-free survival (BRFS) results are presented.

Material and methods: Between 2007 and 2016, 706 patients were treated with real-time technique using Bard-ProLink™ system. 145 Gy was administered to the prostate with exclusive BT and 108 Gy after 46 Gy of external radiotherapy (EBRT). Androgen deprivation therapy was applied in 19.3% of patients.

Results: Median follow-up was 96 months (range, 24-163 months). BRFS at 5 and 10 years was 95% and 91.1%, respectively. For 480 low-risk cases, BRFS at 5 and 10 years was 95.7% and 92.7%, and for 226 intermediate-risk cases, it was 92.7% and 88%, respectively (p < 0.05). With combined treatment of EBRT + BT, 133 cases (59%) of intermediate-risk were treated without differences with exclusive BT. Gleason score 4 + 3 cases dropped to 72.8% at 10 years (p < 0.001), with androgen deprivation therapy (ADT) to 90.9% and without ADT to 66.8%; it was worse if patients had exclusive BT. 10-year BRFS for T1c was 95% compared to 84% for T2 (p < 0.001). Initial prostate specific antigen (PSA) > or < 10 showed no differences. With > 50% biopsy cores positive, it fell to 80% at 10 years (p < 0.001). In 154 patients up to 60 years of age, 10-year BRFS was 97.6%. Urinary complications appeared in 16.9% of cases in exclusive BT vs. 26.1% in EBRT + BT. Grade 2+ urinary late complications were observed in 19.1% and grade 3+ in 5.8% of patients. Rectal toxicity was 4% (2.5% in BT alone and 10.1% in RT + BT), while G3+ was seen in 0.1%.

Conclusions: Real-time BT with custom-linked ¹²⁵I seeds is a very effective long-term treatment in low- and intermediate-risk prostate carcinoma. With Gleason score 4 + 3 or > 50% biopsy cores positive, we recommend combined treatment with additional ADT for 6 months.

Keywords: 125I seeds; brachytherapy; custom-linked seeds; intermediate-risk; long-term; low-risk; prostate.