Focal or whole-gland salvage prostate brachytherapy with iodine seeds with or without a rectal spacer for postradiotherapy local failure: How best to spare the rectum?

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• 作者：Valentine Guimas¹ ; Magali Quivrin¹ ; ² ; Auré ; lie Bertaut³ ; Etienne Martin¹ ; Damien Chambade¹ ; Philippe Maingon¹ ; Fré ; dé ; ric Mazoyer¹ ; Luc Cormier⁴ ; Gilles Cré ; hange¹ ; ² ; ^{gcrehange@cgfl.fr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Prostate cancer ; Local failure ; Salvage brachytherapy ; Low dose rate ; Biologically effective dose
• 刊名：Brachytherapy
• 出版年：2016
• 出版时间：July-August 2016
• 年：2016
• 卷：15
• 期：4
• 页码：406-411
• 全文大小：549 K

文摘

Salvage prostate permanent implant (sPPI) for postradiation local failure provides high rates of biochemical control. The cumulative dose delivered to the prostate and the rectum is still unknown.

Methods and Materials

We reviewed the postimplant CT-based dosimetry of 18 selected patients who underwent sPPI with ¹²⁵I seeds for isolated biopsy-proven local failure several years after external beam radiation therapy. Ten patients had whole-prostate sPPI, and 8 patients had multiparametric MRI-based focal sPPI. In 8 patients, hyaluronic acid (HA) gel was injected into the prostate–rectum space.

Results

The median cumulative biological effective dose after EBRT + sPPI for the prostate and the rectum was higher in patients treated with whole-gland sPPI than in patients treated with focal sPPI (313.5 Gy₂ vs. 174.4 Gy₂; p = 0.06 and 258.1 Gy₃ vs. 172.6 Gy₃; p < 0.01, respectively). The median D_0.1cc for the rectum was significantly lower in patients who had HA gel: 63.3 Gy (29.0–78.3) vs. 83.9 Gy (34.9–180.0) (p = 0.04).

Conclusions

Cumulative prostate and rectum biological effective doses were lower with focal sPPI. D_0.1cc delivered to the rectum was significantly lower with HA gel, while there was no difference between focal or whole-gland plans.