Efficacy and Safety of High-Dose-Rate Brachytherapy of Single Implant with Two Fractions Combined with External Beam Radiotherapy for Hormone-Naïve Localized Prostate Cancer

Abstract

The purpose of this study was to evaluate the efficacy and safety of high-dose-rate (HDR) brachytherapy of a single implant with two fractions plus external beam radiotherapy (EBRT) for hormone-naïve prostate cancer in comparison with radical prostatectomy. Of 150 patients with localized prostate cancer (T1c–T2c), 59 underwent HDR brachytherapy plus EBRT, and 91 received radical prostatectomy. The median follow-up of patients was 62 months for HDR brachytherapy plus EBRT, and 64 months for radical prostatectomy. In patient backgrounds between the two cohorts, the frequency of T2b plus T2c was greater in HDR brachytherapy cohort than in prostatectomy cohort (27% versus 12%, p = 0.029). Patients in HDR brachytherapy cohort first underwent 3D conformal RT with four beams to the prostate to an isocentric dose of 50 Gy in 25 fractions and then, a total of 15–18 Gy in two fractions at least 5 hours apart. We prescribed 9 Gy/fraction for target (prostate gland plus 3 mm lateral outside margin and seminal vesicle) using CT image method for radiation planning. The total biochemical failure-free control rates (BF-FCR) at 3 and 5 years for the HDR brachytherapy cohort, and for the prostatectomy cohort were 92% and 85%, and 72% and 72%, respectively (significant difference, p = 0.0012). The 3-and 5-year BF-FCR in the HDR brachytherapy cohort and in the prostatectomy cohort by risk group was 100 and 100%, and 80 and 80%, respectively, for the low-risk group (p = 0.1418); 92 and 92%, 73 and 73%, respectively, for the intermediate-risk group (p = 0.0492); and 94 and 72%, 45 and 45%, respectively, for the high-risk group (p = 0.0073). After HDR brachytherapy plus EBRT, no patient experienced Grade 2 or greater genitourinay toxicity. The rate of late Grade 1 and 2 GI toxicity was 6% (n = 4). No patient experienced Grade 3 GI toxicity. HDR brachytherapy plus EBRT is useful for treating patients with hormone-naïve localized prostate cancer, and has low GU and GI toxicities.

Prevalence and Risk Factors of Emotional Distress in Patients With Prostate Cancer Assigned to External-beam Radiotherapy With or Without High-dose Rate Brachytherapy

“…This finding may be explained by the fact that HDR brachytherapy is safe and associated with less toxicity than EBRT alone (3,21). For example, in the study of Noda et HDR brachytherapy boost (21). However, although the results of the present study agree with those of previous studies or, if novel, can be sufficiently explained, the retrospective design and the risk of a hidden selection bias need to be considered when interpreting the results.…”

“…Another result of the present study was a trend between EBRT without an HDR brachytherapy boost and a higher prevalence of emotional problems. This finding may be explained by the fact that HDR brachytherapy is safe and associated with less toxicity than EBRT alone (3,21). For example, in the study of Noda et HDR brachytherapy boost (21).…”

Radiation dose to rectum in high-dose-rate brachytherapy with a single implant and two fractions for prostate cancer, and its prediction by prostate volume

“…Akimoto et al [8] reported that this incidence was 10 % following 51 Gy EBRT and 18-25 Gy HDR brachytherapy (5-9 Gy/fraction) given over 1, 2, or 3 days. In this study with 50 Gy EBRT (2 Gy/fraction) and 15-18 Gy HDR brachytherapy (2 Gy/fraction) given in a half day, the incidence of rectal bleeding was less than 1 % [1,18]. The previous reports implied that the incidence of rectal bleeding was related to the length of time that the needle remained in the body.…”

High‐dose‐rate brachytherapy for prostate cancer: Rationale, current applications, and clinical outcome

“…The supplemental EBRT doses range from 45 to 54 Gy (normofractionation), generating total BED 1.5 and EQD2 doses in the range of 171–366 Gy and 74–137 Gy, respectively. 9 , 10 , 14 , 15 , 16 , 56 , 59 , 68 , 69 , 79 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 The reported severe late GU and GI adverse events rates compare favorably with late toxicity rates in dose‐escalated EBRT series. 71 , 105 , 106 , 108 It must be noted that hypofractionated EBRT protocols are gaining momentum, 94 , 95 appearing equieffective in regard to clinical outcome, while demonstrating favorable toxicity profile.…”