Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
Int J Radiat Oncol Biol Phys. 2017 Feb 1;97(2):372-380. doi: 10.1016/j.ijrobp.2016.10.031. Epub 2016 Oct 26.
We previously reported that pretreatment positron emission tomography (PET) identifies lesions at high risk for progression after concurrent chemoradiation therapy (CRT) for locally advanced non-small cell lung cancer (NSCLC). Here we validate those findings and generate tumor control probability (TCP) models.
We identified patients treated with definitive, concurrent CRT for locally advanced NSCLC who underwent staging F-fluorodeoxyglucose/PET/computed tomography. Visible hypermetabolic lesions (primary tumors and lymph nodes) were delineated on each patient's pretreatment PET scan. Posttreatment imaging was reviewed to identify locations of disease progression. Competing risks analyses were performed to examine metabolic tumor volume (MTV) and radiation therapy dose as predictors of local disease progression. TCP modeling was performed to describe the likelihood of local disease control as a function of lesion size.
Eighty-nine patients with 259 hypermetabolic lesions (83 primary tumors and 176 regional lymph nodes) met the inclusion criteria. Twenty-eight patients were included in our previous report, and the remaining 61 constituted our validation cohort. The median follow-up time was 22.7 months for living patients. In 20 patients, the first site of progression was a primary tumor or lymph node treated with radiation therapy. The median time to progression for those patients was 11.5 months. Data from our validation cohort confirmed that lesion MTV predicts local progression, with a 30-month cumulative incidence rate of 23% for lesions above 25 cc compared with 4% for lesions below 25 cc (P=.008). We found no evidence that radiation therapy dose was associated with local progression risk. TCP modeling yielded predicted 30-month local control rates of 98% for a 1-cc lesion, 94% for a 10-cc lesion, and 74% for a 50-cc lesion.
Pretreatment FDG-PET identifies lesions at risk for progression after CRT for locally advanced NSCLC. Strategies to improve local control should be tested on high-risk lesions, and treatment deintensification for low-risk lesions should be explored.
我们之前报道过，在局部晚期非小细胞肺癌（NSCLC）同步放化疗（CRT）后，治疗前正电子发射断层扫描（PET）可识别出高进展风险的病变。在此，我们验证了这些发现并生成了肿瘤控制概率（TCP）模型。
我们确定了接受局部晚期 NSCLC 根治性同步 CRT 治疗的患者，这些患者在接受分期 F-氟脱氧葡萄糖/PET/计算机断层扫描。在每位患者的治疗前 PET 扫描上勾画可见高代谢病变（原发肿瘤和淋巴结）。回顾治疗后的影像学资料，以确定疾病进展的部位。采用竞争风险分析来研究代谢肿瘤体积（MTV）和放疗剂量作为局部疾病进展的预测因子。采用 TCP 模型来描述病变大小与局部疾病控制概率的关系。
89 例 259 个高代谢病变（83 个原发肿瘤和 176 个区域淋巴结）符合纳入标准。28 例患者包含在我们之前的报告中，其余 61 例构成了我们的验证队列。有存活患者的中位随访时间为 22.7 个月。在 20 例患者中，首次进展部位是接受放疗的原发肿瘤或淋巴结。这些患者的中位进展时间为 11.5 个月。验证队列的数据证实，病变 MTV 可预测局部进展，25 cc 以上病变的 30 个月累积发生率为 23%，而 25 cc 以下病变的发生率为 4%（P=.008）。我们没有发现放疗剂量与局部进展风险相关的证据。TCP 模型预测 1 cc 病变的 30 个月局部控制率为 98%，10 cc 病变为 94%，50 cc 病变为 74%。
治疗前 FDG-PET 可识别出局部晚期 NSCLC 同步放化疗后进展风险高的病变。应在高危病变上测试提高局部控制率的策略，并探索低危病变的治疗强度降低策略。
