Comparison of implant quality between intraoperatively built custom-linked seeds and loose seeds in permanent prostate brachytherapy using sector analysis.

Norihisa Katayama,Kuniaki Katsui,Susumu Kanazawa,Mitsuhiro Takemoto,Shin Ebara,Yasutomo Nasu,Hiroki Ihara,Atsushi Takamoto

doi:10.1093/jrr/rrw018

Norihisa Katayama, Kuniaki Katsui + Show 6 more

Open Access

https://doi.org/10.1093/jrr/rrw018

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Abstract

We compared the implant quality of intraoperatively built custom-linked (IBCL) seeds with loose seeds in permanent prostate brachytherapy. Between June 2012 and January 2015, 64 consecutive prostate cancer patients underwent brachytherapy with IBCL seeds (n = 32) or loose seeds (n = 32). All the patients were treated with 144 Gy of brachytherapy alone. Brachytherapy was performed using a dynamic dose calculation technique. Computed tomography/magnetic resonance imaging fusion-based dosimetry was performed 1 month after brachytherapy. Post-implant dose–volume histogram (DVH) parameters, prostate sector dosimetry, operation time, seed migration, and toxicities were compared between the IBCL seed group and the loose seed group. A sector analysis tool was used to divide the prostate into six sectors (anterior and posterior sectors at the base, mid-gland, and apex). V100 (95.3% vs 89.7%; P = 0.014) and D90 (169.7 Gy vs 152.6 Gy; P = 0.013) in the anterior base sector were significantly higher in the IBCL seed group than in the loose seed group. The seed migration rate was significantly lower in the IBCL seed group than in the loose seed group (6% vs 66%; P < 0.001). Operation time per seed was significantly longer in the IBCL seed group than in the loose seed group (1.31 min vs 1.13 min; P = 0.003). Other post-implant DVH parameters and toxicities did not differ significantly between the two groups. Our study showed more dose coverage post-operatively in the anterior base prostate sector and less seed migration in IBCL seed implantation compared with loose seed implantation.

Highlights

Permanent prostate brachytherapy (PPB) has become a standard treatment option for patients with localized prostate cancer, with longterm local and biochemical control similar to outcomes observed after radical prostatectomy and external beam radiation therapy (EBRT) [1,2,3]
V100 (95.3% vs 89.7%; P = 0.014) and D90 (169.7 Gy vs 152.6 Gy; P = 0.013) in the anterior base sector were significantly higher in the intraoperatively built custom-linked (IBCL) seed group than in the loose seed group
The seed migration rate was significantly lower in the IBCL seed group than in the loose seed group (6% vs 66%; P < 0.001)

Summary

Introduction

Permanent prostate brachytherapy (PPB) has become a standard treatment option for patients with localized prostate cancer, with longterm local and biochemical control similar to outcomes observed after radical prostatectomy and external beam radiation therapy (EBRT) [1,2,3]. In Japan, PPB was first adopted in 2003, and 109 institutions have used this treatment for 27 000 cases throughout the country up to the end of 2013 [4]. Because stranded or linked seeds had not been introduced until 2012, only loose seeds had been used for PPB until . An intraoperatively built custom-linked (IBCL) seeds system is a push-button seed delivery system that allows the user to create 393. Intraoperatively customized linked seeds, using a combination of seeds, connectors and spacers. Zauls et al first reported this system in 2010 [5]. It was introduced into Japan in 2012

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