非手术喉癌、下咽癌患者放化疗前后MRI检查的应用价值

Clinical efficacy of follow-up MRI before and after chemoradiotherapy for patients with nonsurgical laryngeal and hypopharyngeal carcinoma

目的探讨非手术喉癌、下咽癌患者放化疗前后MRI检查的临床应用价值。方法 25例经病理检查证实为鳞状细胞癌的非手术喉癌、下咽癌患者(仅接受放化疗)治疗前及接受治疗后3个月、6个月、9个月、12个月定期行常规MRI平扫、增强扫描检查。观察病灶治疗前后MRI影像学表现,测量并比较治疗前、治疗后横轴位病灶最大面积的变化及治疗前、治疗后T2WI图像中喉部及下咽部非肿瘤组织的信噪比(signal-to-noise ratio,SNR)和对比噪声比(contrast-to-noise ratio,CNR);对10例治疗前、治疗后均行磁共振扩散加权成像(diffusion weighted imaging,DWI)检查的患者,测量并比较治疗前、治疗后病灶区域的表观扩散系数(apparent diffusion coefficient,ADC)值的变化。结果 25例患者接受治疗后肿物的最大横截面积明显缩小(P<0.05),其中17例接受治疗后第3个月复查时肿物已消失,第6个月、第9个月复查时分别有4例肿物消失。接受治疗后3个月与治疗前相比,喉部及下咽部非肿瘤组织SNR值的差异无统计学意义(P=0.136);接受治疗后6个月、9个月、12个月非肿瘤组织的SNR值及各个时间点的CNR值均较治疗前显著升高(P均<0.05)。10例患者治疗后病灶区域的ADC值均高于治疗前,差异有统计学意义(P<0.05)。结论 MRI检查可以清晰显示喉癌、下咽癌病灶的变化,大部分喉癌、下咽癌患者在接受治疗后3个月内肿物消失;SNR值、CNR值对于观测治疗前后组织水肿的变化有临床价值;ADC值对于评价喉癌、下咽癌的疗效有一定意义。

Objective To explore the clinical value of follow-up MRI before and after chemoradiotherapy for patients with non-surgical laryngeal or hypopharyngeal carcinoma. Methods Twenty five patients with non-surgical laryngeal or hypopharyngeal squamous cell carcinoma were analyzed . These patients had pathologically confirmed disease and underwent routine contrast-enhanced MRI examination before chemoradiotherapy and at 3,6,9,and 12 months afterwards. Change in the largest area of the primary lesion was monitored,and edema status was assessed using the signal-to-noise ratio（SNR）and contrast-to-noise ratio（CNR）of non-tumor tissue on T2-weighted images. Diffusion-weighted imaging （DWI）were obtained for 10 patients,and the apparent diffusion coefficient（ADC） parameter was monitored in this subgroup. Results In all patients,the largest area of the primary lesion decreased significantly during follow-up （P〈0.05）,and the primary lesion could not be detected in 17 patients by 3 months after chemoradiotherapy,in another 4 patients by 6 months afterwards,and in another 4 patients by 9 months afterwards. SNR of non-tumor tissue was similar before chemoradiotherapy and at 3 months afterwards,and it was significantly higher than pre-therapy at all other time points. CNR of non-tumor tissue was significantly higher at all post-therapy time points than before therapy （P〈0.05）. ADC in the subgroup of 10 patients was significantly higher after therapy （P〈0.05）. Conclusion MRI can clearly detect changes in the primary lesion of laryngeal and hypopharyngeal carcinoma. Most lesions were undetectable within 3 months after therapy. Monitoring SNR and CNR may help evaluate changes in non-tumor tissue edema,and monitoring the ADC parameter may help assess treatment response.