Department of Oncology, Helsinki University Hospital and University of Helsinki, Finland.
Department of Oncology, Lund University, Sweden.
Radiother Oncol. 2015 Aug;116(2):233-8. doi: 10.1016/j.radonc.2015.07.025. Epub 2015 Jul 27.
Gastrointestinal stromal tumor (GIST) has been considered radiation-resistant, and radiotherapy is recommended only for palliation of bone metastases in current treatment guidelines. No registered prospective trial has evaluated GIST responsiveness to radiotherapy.
Patients with GIST progressing at intra-abdominal sites or the liver were entered to this prospective Phase II multicenter study (identifier NCT00515931). Metastases were treated with external beam radiotherapy using either conformal 3D planning or intensity modulated radiotherapy and conventional fractionation to a cumulative planning target volume dose of approximately 40 Gy. Systemic therapy was maintained unaltered during the study.
Of the 25 patients entered, 19 were on concomitant tyrosine kinase inhibitor therapy, most often imatinib. Two (8%) patients achieved partial remission, 20 (80%) had stable target lesion size for ⩾3 months after radiotherapy with a median duration of stabilization of 16 months, and 3 (12%) progressed. The median time to radiotherapy target lesion progression was 4-fold longer than the median time to GIST progression at any site (16 versus 4 months). Radiotherapy was generally well tolerated.
Responses to radiotherapy were infrequent, but most patients had durable stabilization of the target lesions. GIST patients with soft tissue metastases benefit frequently from radiotherapy.
胃肠道间质瘤（GIST）被认为具有放射抵抗性，目前的治疗指南仅推荐对骨转移进行姑息性放疗。没有注册的前瞻性试验评估过 GIST 对放疗的反应。
本前瞻性 II 期多中心研究（标识符 NCT00515931）纳入了进展至腹腔内部位或肝脏的 GIST 患者。采用适形 3D 计划或调强放疗和常规分割技术对转移灶进行外照射放疗，使累积计划靶区剂量达到约 40Gy。研究期间维持不变的系统治疗。
在纳入的 25 例患者中，19 例同时接受酪氨酸激酶抑制剂治疗，最常用的是伊马替尼。2 例（8%）患者达到部分缓解，20 例（80%）患者在放疗后 ⩾3 个月时靶病变大小稳定，稳定时间的中位数为 16 个月，3 例（12%）进展。放疗靶病变进展的中位时间是 GIST 任何部位进展时间的 4 倍（16 个月 vs. 4 个月）。放疗总体耐受良好。
放疗反应罕见，但大多数患者的靶病变稳定时间持久。软组织转移的 GIST 患者经常从放疗中获益。
