Anderson Elliot, Smyth Lloyd M L, O'Sullivan Richard, Ryan Andrew, Lawrentschuk Nathan, Grummet Jeremy, See Andrew W
Department of Surgery, Central Clinical School, Monash University, Melbourne, Australia.
Icon Cancer Centre, Richmond, Australia.
Transl Androl Urol. 2021 Sep;10(9):3591-3603. doi: 10.21037/tau-21-508.
Focal treatment for prostate cancer (PCa) is a hybrid approach combining ablative treatment of the involved prostate gland and continued active surveillance (AS) of the unaffected gland. Low dose-rate (LDR) brachytherapy can be used as a lesion-targeted focal therapy, however, further studies are required to support its use. The aim of this study is to evaluate the dosimetry, toxicity and oncological outcomes of men receiving lesion-targeted focal LDR brachytherapy for low to intermediate risk PCa.
This is a retrospective cohort study of 26 men with unifocal, low to intermediate grade PCa diagnosed on a combination of multiparametric-magnetic resonance imaging (mp-MRI) and targeted plus template transperineal (TP) biopsy, who received focal LDR brachytherapy at a single institution. Brachytherapy involved a single monotherapy implant using iodine-125 seeds to deliver a prescribed dose of 145 Gy to the index lesion.
The mean focal planning target volume (F-PTV) as a percentage of the prostate volume was 24.5%. The percentage of the focal gross tumour volume (F-GTV) receiving 100% of the prescription dose was 100% for 12 patients and ≥98% for 18 patients. The median follow-up for toxicity and biochemical control outcomes was 23.1 [interquartile range (IQR) 19.1-31.3] and 24.2 (IQR 17.9-30.0) months, respectively. Grade 2 urinary and erectile toxicities were reported by 29.2% and 45.8% of patients, respectively, with resolution of urinary symptoms to baseline by last follow-up. There were no grade ≥3 urinary or erectile toxicities or grade ≥2 rectal toxicity. All 21 patients who underwent a repeat mp-MRI and TP biopsy at 12-24 months post-treatment were negative for clinically significant disease and 25 (96.2%) patients were free from biochemical failure (FFBF).
Focal LDR brachytherapy is associated with a favourable toxicity profile and a high rate of control of significant PCa at 12-18 months post-treatment. We have commenced the LIBERATE prospective registry in focal LDR brachytherapy based on the highly encouraging outcomes of this initial experience.
前列腺癌（PCa）的局部治疗是一种混合方法，将受累前列腺腺体的消融治疗与未受影响腺体的持续主动监测（AS）相结合。低剂量率（LDR）近距离放射治疗可作为一种针对病灶的局部治疗方法，然而，仍需要进一步研究来支持其应用。本研究的目的是评估接受针对低至中度风险PCa的病灶靶向局部LDR近距离放射治疗的男性的剂量学、毒性和肿瘤学结局。
这是一项回顾性队列研究，研究对象为26名经多参数磁共振成像（mp-MRI）和靶向加模板经会阴（TP）活检联合诊断为单灶、低至中度分级PCa的男性，他们在单一机构接受了局部LDR近距离放射治疗。近距离放射治疗采用单一的单药植入，使用碘-125种子向靶病灶给予规定剂量的145 Gy。
平均局部计划靶体积（F-PTV）占前列腺体积的百分比为24.5%。12例患者接受100%处方剂量的局部大体肿瘤体积（F-GTV）百分比为100%，18例患者≥98%。毒性和生化控制结局的中位随访时间分别为23.1[四分位间距（IQR）19.1 - 31.3]个月和24.2（IQR 17.9 - 30.0）个月。分别有29.2%和45.8%的患者报告有2级泌尿系统和勃起功能毒性，至最后一次随访时泌尿系统症状恢复至基线水平。没有≥3级泌尿系统或勃起功能毒性或≥2级直肠毒性。所有21例在治疗后12 - 24个月接受重复mp-MRI和TP活检的患者均未发现临床显著疾病，25例（96.2%）患者无生化失败（FFBF）。
局部LDR近距离放射治疗具有良好的毒性特征，在治疗后12 - 18个月对显著PCa的控制率较高。基于这一初步经验的高度鼓舞人心的结果，我们已启动了关于局部LDR近距离放射治疗的LIBERATE前瞻性注册研究。
