Sanmamed Noelia, Glicksman Rachel M, Helou Joelle, Chung Peter, Berlin Alejandro
Department of Radiation Oncology, University of Toronto, Canada.
Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Canada.
Tech Innov Patient Support Radiat Oncol. 2019 Oct 15;11:22-25. doi: 10.1016/j.tipsro.2019.08.002. eCollection 2019 Sep.
The risk of gastrointestinal (GI) toxicity may limit the use of curative-intent radical radiotherapy (RT) for prostate cancer (PCa) in circumstances where morbidity of treatment may exceed an acceptable threshold. Rectal spacers are used to expand the distance between the anterior rectal wall and the prostate, consequently sparing the rectum from the high-dose region.
We report three clinical scenarios of PCa patients treated at our institution, where risk of RT-associated rectal toxicity may be increased: inflammatory bowel disease (IBD), salvage brachytherapy (BT) after previous external beam RT (EBRT), and tailored dose-escalation with focal BT to the gross tumor volume followed by stereotactic body RT. Prior to RT, a polyethylene glycol (PEG) hydrogel spacer was successfully placed in all cases. Treatment comprised magnetic resonance (MR) guided high dose-rate BT ± EBRT. All patients completed treatment uneventfully, without any significant GI toxicity at last follow-up.
These cases illustrate the utility of PEG hydrogel spacer, where concerns of radiation induced toxicity may have previously limited the application of radiotherapy. The synergistic use of these novel devices together with MR-guided BT may expand the indications and therapeutic index of curative-intent RT-based treatments, while minimizing the risks of GI toxicity.
在治疗的发病率可能超过可接受阈值的情况下，胃肠道（GI）毒性风险可能会限制前列腺癌（PCa）根治性放疗（RT）的应用。直肠间隔器用于扩大直肠前壁与前列腺之间的距离，从而使直肠免受高剂量区域的影响。
我们报告了在我们机构接受治疗的3例PCa患者的临床情况，其中RT相关直肠毒性风险可能增加：炎症性肠病（IBD）、先前外照射放疗（EBRT）后挽救性近距离放疗（BT），以及对大体肿瘤体积进行局部BT并随后进行立体定向体部放疗的定制剂量递增。在放疗前，所有病例均成功置入聚乙二醇（PEG）水凝胶间隔器。治疗包括磁共振（MR）引导的高剂量率BT±EBRT。所有患者均顺利完成治疗，最后一次随访时无任何明显的胃肠道毒性。
这些病例说明了PEG水凝胶间隔器的实用性，在之前辐射诱导毒性的担忧可能限制放疗应用的情况下。这些新型装置与MR引导的BT协同使用，可能会扩大基于根治性放疗的治疗的适应症和治疗指数，同时将胃肠道毒性风险降至最低。
