Hopper Austin B, Sandhu Ajay P S, Parsons J Kellogg, Rose Brent, Einck John P
Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
Department of Urology, University of California San Diego, La Jolla, California.
Adv Radiat Oncol. 2017 Sep 27;3(1):52-56. doi: 10.1016/j.adro.2017.09.001. eCollection 2018 Jan-Mar.
Cryotherapy is an option for the primary treatment of localized prostate cancer, along with radical prostatectomy, external beam radiation therapy, and brachytherapy. Although it is known that local recurrence can occur in >20% of patients treated with primary cryotherapy, unfortunately there is a paucity of data on later salvage treatments. The use of external beam radiation therapy is an attractive option after cryotherapy failure, but there is little data on its efficacy and toxicity. We evaluated the biochemical control and complication rates of salvage dose-escalated image guided intensity modulated radiation therapy (IG-IMRT) after cryotherapy failure.
Patients who were treated at our institution from 2005 to 2016 were reviewed for those who underwent cryotherapy as initial treatment followed by salvage IGRT. Patients were treated with dose-escalated IG-IMRT using standard treatment margins of 3 mm posterior and 7 mm in all other directions and daily cone beam computed tomography or kv imaging to implanted fiducial markers. Biochemical progression was defined in accordance with the Phoenix consensus conference definition.
Eight patients were identified as having received post-cryotherapy salvage radiation within the study period. The median total dose was 77.7 Gy (range, 75.6-81.0 Gy). Median follow-up was 55 months (range, 6-88 months). Six patients remained biochemically controlled at the latest follow-up. One patient developed distant metastases after 22 months and one experienced biochemical failure at 30 months with no evidence of distant metastases. No patients experienced acute gastrointestinal toxicities of grade 2 or higher. There were no cases of late gastrointestinal or genitourinary toxicity.
High-dose IG-IMRT results in high rates of salvage and extremely low rates of serious late toxicity for patients with locally recurrent prostate cancer after cryotherapy. Although the results are encouraging, given the small number of patients in this and other series, we remain cautious with regard to this treatment and believe the use of salvage radiation therapy after cryotherapy warrants further study.
冷冻疗法是局限性前列腺癌的主要治疗选择之一，与根治性前列腺切除术、外照射放疗和近距离放射治疗一样。虽然已知接受初次冷冻治疗的患者中超过20%会出现局部复发，但遗憾的是，关于后续挽救性治疗的数据很少。冷冻治疗失败后使用外照射放疗是一个有吸引力的选择，但关于其疗效和毒性的数据很少。我们评估了冷冻治疗失败后挽救性剂量递增影像引导调强放射治疗（IG-IMRT）的生化控制情况和并发症发生率。
回顾了2005年至2016年在我们机构接受治疗的患者，筛选出那些接受初次冷冻治疗后再进行挽救性IGRT的患者。患者接受剂量递增的IG-IMRT治疗，标准治疗边界为后方3毫米，其他方向7毫米，每天进行锥形束计算机断层扫描或千伏成像以确定植入的基准标记。生化进展根据凤凰城共识会议的定义确定。
在研究期间，8名患者被确定接受了冷冻治疗后的挽救性放疗。总剂量中位数为77.7 Gy（范围为75.6 - 81.0 Gy）。中位随访时间为55个月（范围为6 - 88个月）。在最近一次随访时，6名患者保持生化控制。1名患者在22个月后发生远处转移，1名患者在30个月时出现生化失败，无远处转移证据。没有患者出现2级或更高等级的急性胃肠道毒性。没有发生晚期胃肠道或泌尿生殖系统毒性病例。
对于冷冻治疗后局部复发的前列腺癌患者，高剂量IG-IMRT导致高挽救率和极低的严重晚期毒性发生率。尽管结果令人鼓舞，但鉴于本系列及其他系列患者数量较少，我们对这种治疗仍持谨慎态度，并认为冷冻治疗后使用挽救性放疗值得进一步研究。
