宫颈癌放射治疗疗效的MRI评价

MRI evaluation of treatment effect of radiotherapy for cancer of uterine cervix

目的分析宫颈癌放射治疗中与后MRI表现,探讨MRI成像对宫颈癌放射治疗疗效评估的价值。方法23例经病理证实的宫颈癌患者在放射治疗前、中及后不同时间段行盆腔的轴位T1WI,轴位及矢状位T2WI,冠状位SPIR,以及GDDTPA增强后T1WI的轴位、冠状位、矢状位扫描。在MRI图像上观察肿瘤在放射治疗前、后的大小及信号改变。结果外照射结束时,9例肿瘤缩小率在85%以下,14例>85%。T1WI增强扫描7例见肿瘤内出现“无强化区”,其中6例放射治疗结束后有肿瘤残留;16例肿瘤未见“无强化区”,其中13例肿瘤缩小率>85%,仅2例放射治疗后有肿瘤残留。MRI图像上,肿瘤痊愈表现为T2WI、SPIR序列呈低信号,T1WI增强扫描轻微强化或无强化。结论MRI成像可反应肿瘤对射线的疗效。外照射结束时肿瘤容积缩小程度与T1WI增强肿瘤内有无“无强化区”是预测放射治疗效果的重要观测指标。

Objective To present the findings of cervical carcinoma before, during and after radiation therapy by magnetic resonance(MR)imaging and to investigate MR images in the evaluation of cervical carcinoma response to radiation therapy. Methods Pelvic MR imaging was performed before, during, and at different intervals after radiation therapy in 23 patients with cervical carcinoma. The MR scanning included axial T1W, SE, axial and sagittal T2WI TSE, coronal SPIR and axial, sagittal and coronal GD DTPA enhanced T1WI SE. The changes of carcinoma lesion in size and signal were evaluated on MR images. Results At the end of external beam radiotherapy (EBRT), the extent of tumor volume shrinkage was less than 85% in 9 patients and more than 85% in 14 patients. 'No enhanced area' in carcinoma lesion was observed in 7 patients at GD DTPA enhanced T1W imaging, of them 6 showed residual tumor after radiation treatment. In 16 patients who did not present 'No enhanced area', 13 patients showed tumor shrinkage at the end of EBRT greater than 85%. Moreover, only 2 patients were demonstrated as having tumor residual after radiation treatment. Complete response to radiation therapy were usually presented as hypotense signal at T2W, SPIR MR image and slight or no enhancement at GD DTPA T1W images. Conclusion MR imaging is helpful in evaluating cervical carcinoma response to radiation therapy with the extent of tumor volume shrinkage and enhanced T1W findings at the end of EBRT as the important prognostic factors in determining the treatment outcome.