High-dose-rate brachytherapy as monotherapy for low- and intermediate-risk prostate cancer: long-term experience of Swedish single-center

Bengt Johansson; Johan Staby Olsén; Leif Karlsson; Erik Lundin; Bo Lennernäs

doi:10.5114/jcb.2021.105846

High-dose-rate brachytherapy as monotherapy for low- and intermediate-risk prostate cancer: long-term experience of Swedish single-center

J Contemp Brachytherapy. 2021 Jun;13(3):245-253. doi: 10.5114/jcb.2021.105846. Epub 2021 May 5.

Authors

Bengt Johansson¹, Johan Staby Olsén², Leif Karlsson³, Erik Lundin¹, Bo Lennernäs¹

Affiliations

¹ Department of Oncology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
² Department of Oncology, Central Hospital of Karlstad, Karlstad, Sweden.
³ Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.

Abstract

Purpose: Until now, most long-term results for brachytherapy only has been published for low-dose-rate (LDR) seeds. Due to radiobiology reasons, high-dose-rate (HDR) mono-brachytherapy is of growing interest. The aim of the study was to report long-term biochemical control rate and toxicities with HDR monotherapy.

Material and methods: This was a retrospective single-institution experience, including 229 men, clinically staged T1c-T2b, Gleason 3 + 3 (prostate specific antigen (PSA) ≤ 15), or Gleason 3 + 4 (PSA ≤ 10), consecutively treated between 2004 and 2012 with HDR brachytherapy alone, using three different fractionation schedules of 92-95 Gy (EQD(2), α/β = 3). Group 4F (n = 19) had a single implant of 9.5 Gy in four fractions over 2 days. Group 3F (n = 107) had three separate implants of 11 Gy over 4 weeks. Group 2F (n = 103) had two implants of 14 Gy over 2 weeks. No adjuvant hormonal therapy was allowed.

Results: For 4F, 3F, and 2F study groups, median follow-up was 10.2, 7.1, and 6.1 years, respectively, and biochemical failure rate was 10.5%, 4.7%, and 14.6%, respectively. Early and late side effects were followed with common terminology criteria version 2.0 and patient-reported questionnaires. There were a temporary acute urethral toxicity increase, 1-2 grades over baseline lower urinary tract symptoms (LUTS), which usually recovered. About 1/3 of the patients had a remaining one grade over baseline LUTS. Severe grade 3-4 toxicity were only found in 3.5% of patients. No rectal toxicity was observed. Erectile dysfunction (ED) was depending on age and erectile function before treatment. In patients without ED before the treatment, we found a complete ED in 21% of men at the last follow-up.

Conclusions: In the present study, HDR mono-brachytherapy was found to be an effective treatment, with mild long-term side effects difficult to differentiate from aging effects. There were no significant differences in PSA regression, PSA failure rate, and toxicity between the different fraction schedules.

Keywords: HDR; brachytherapy; monotherapy; outcome; prostate cancer.