肺癌脑转移立体定向放疗后MRI变化及对近期疗效评价影响

目的 评价肺癌脑转移SRT后MRI变化及对RECIST下疗效的影响。方法 回顾分析SRT的31例肺癌脑转移病例的60个病灶,评价疗后MRI表现及按RECIST记录的疗效。结果60个病灶SRT后MRI评价如下:(1)14个病灶复发,其中8个结节状强化增强、5个均匀强化、1个不均匀强化;(2)11个病灶(18%)为可疑进展,其中均匀强化5个、不均匀强化3个、厚壁强化2个、结节状强化1个;(3) 35个病灶控制,其中19个体积缩小或消失,10个体积和疗前变化不明显,6个较疗前体积增大;(4)有效率为76.7%(可疑进展+控制病灶)。RECIST评价结果为15个病灶CR (25%)、9个病灶PR (15%)、12个病灶SD (20%)、24个病灶PD (40%),有效率为40%。结论 肺癌脑转移SRT后影像学表现多样,且18%病灶难以根据MRI变化判断性质;RECIST低估了近期疗效。

Evaluation of MRI findings and short-term outcome in lung cancer patients with brain metastases after stereotactic radiotherapy

Objective To evaluate the treatment outcomes in lung cancer patients with brain metastases (BM) after stereotactic radiotherapy (SRT) according to magnetic resonance imaging (MRI) findings and the Response Evaluation Criteria In Solid Tumors (RECIST). Methods A retrospective analysis was performed on 31 lung cancer patients with 60 BM lesions who were treated with SRT. Tumor responses were evaluated according to MRI findings and the RECIST. Results The MRI after SRT showed that (1) 14 lesions recurred, with nodular enhancement in 8 lesions, homogeneous enhancement in 5 lesions, and inhomogeneous enhancement in 1 lesion;(2) 11 lesions (18%) had suspected progression, with homogeneous enhancement in 5 lesions, inhomogeneous enhancement in 3 lesions, peripheral enhancement in 2 lesions, and nodular enhancement in 1 lesion;(3) 35 lesions were controlled, with decreased volume or disappearance in 19 lesions, insignificant volume change in 10 lesions, and increased volume in 6 lesions;(4) the overall response rate was 76.7%(suspected progression+ controlled). According to the RECIST, 15 lesions (25%) achieved a complete response (CR), 9 lesions (15%) achieved a partial response (PR), 12 lesions (20%) had stable disease, and 24 lesions (40%) had progressive disease, and the response rate (CR+PR) was 40%. Conclusions There are various MRI findings for brain metastases in lung cancer patients after SRT, and 18% of the lesions are difficult to evaluate by MRI. RECIST underestimates the short-term effect of SRT.