LDR-BT with or without EBRT

The implant technique has been described in detail previously²⁰. All patients underwent transrectal ultrasound preplanning 3–4 weeks before implantation to determine the number of seeds. Permanent intraoperative Iodine-125 implantation using a modified peripheral loading method. We used combination therapy (LDR + EBRT) for T3 or Gleason score sum ≤ 8, or Gleason score sum 7 (4 + 3) cases (not for Gleason score sum 7 (3 + 4) cases) (Fig. 1). The prescription dose for the clinical target volume (prostate) was 145 Gy (LDR alone) or 110 Gy [LDR with 40 Gy/ 20 fractions EBRT by three-dimensional conformal radiotherapy (3D-CRT)].

Scheme of treatments according to National Comprehensive Cancer Network (NCCN) risk classification. Abbreviations; BT brachytherapy, HDR high-dose-rate, LDR low-dose-rate, EBRT external beam radiotherapy, UHF ultrahypofractionated radiotherapy, L-UHF low dose UHF EQD2 < 100 Gy1.5 (α/β = 1.5), H-UHF high dose UHF EQD2 ≥ 100 Gy1.5 (α/β = 1.5).