Reduction of toxicity in brachytherapy using a new technique

Yuji Miyazaki; Yukiho Takenaka; Yasutaka Noda; Nobuyuki Kawai; Takanori Yoshikawa; Takahito Wakamiya; Isao Hara; Tetsuo Sonomura

doi:10.1016/j.brachy.2021.02.002

Reduction of toxicity in brachytherapy using a new technique

Brachytherapy. 2021 Jul-Aug;20(4):866-872. doi: 10.1016/j.brachy.2021.02.002. Epub 2021 Apr 23.

Authors

Yuji Miyazaki¹, Yukiho Takenaka², Yasutaka Noda³, Nobuyuki Kawai³, Takanori Yoshikawa⁴, Takahito Wakamiya⁵, Isao Hara⁵, Tetsuo Sonomura³

Affiliations

¹ Department of Central Radiology, Wakayama Medical University Hospital, Wakayama, Japan. Electronic address: ym@wakayama-med.ac.jp.
² Department of Central Radiology, Wakayama Medical University Hospital, Wakayama, Japan.
³ Department of Radiology, Wakayama Medical University, Wakayama.
⁴ Clinical Research Center, Wakayama Medical University, Wakayama.
⁵ Department of Urology, Wakayama Medical University, Wakayama Prefecture, Japan.

PMID: 33896731
DOI: 10.1016/j.brachy.2021.02.002

Abstract

Purpose: The purpose of the study was to elucidate the usefulness of a dose evaluation method for reducing late genitourinary (GU) toxicity in high-dose-rate brachytherapy (HDR-BT) of prostate cancer.

Methods and materials: GU toxicity was scored in accordance with the Common Terminology Criteria for Adverse Events version 4.0. The prostatic urethra was divided into three segments (base = B, midgland = M, apex = A), which were subclassified into seven subgroups (B, M, A, BM, BA, MA, BMA) using a D_10% color map of the urethra. Significance testing was conducted on urethral D_0.1% and D_10% among the seven subgroups. Grade < 2 GU toxicity was also implemented.

Results: Data of 174 patients with localized prostate cancer treated with HDR-BT combined with external beam radiotherapy between November 2011 and July 2014 were analyzed retrospectively. Median age was 74 (53-84) years, and median followup period was 44 (6-69) months. The number of Grade < 2 and Grade ≥ 2 toxicity was significantly different in the M subgroup than in the other subgroups (p < 0.05), suggesting increased radioresistance in the midgland urethra.

Conclusions: A high-dose-area evaluation method using a urethral D_10% color map may be helpful in reducing late GU toxicity in HDR-BT for prostate cancer.

Keywords: Brachytherapy/AE; Brachytherapy/MT; Prostatic neoplasms/RT; Risk factors; Urethra/RE.

MeSH terms

Aged
Brachytherapy* / methods
Humans
Male
Prostatic Neoplasms* / radiotherapy
Radiation Injuries*
Radiotherapy Dosage
Retrospective Studies
Urogenital System