MR动态增强成像对宫颈癌放化疗后短期治疗效果的预测作用研究

目的 探讨MR动态增强成像(DCE)能否预测宫颈癌放疗和(或)化疗的短期治疗效果.方法 搜集32例经病理证实的宫颈癌患者资料,治疗前行MR DCE扫描,并于放疗和(或)化疗2～3周的早期点及放疗结束后1个月内为时间点行常规MR检查,计算体积变化率,根据病灶是否残余将患者分有残余组和无残余组,采用两独立样本的秩和检验比较各径线、体积和5个DCE指标(平均强化时间,正性积分,达峰时间,最大上升斜率和最大下降斜率)的差异,采用Spearman相关性检验分析早期点径线变化率、体积变化率与治疗前DCE指标的关系.结果 无残余组20例,有残余组12例.无残余组治疗前横断面长径[(47.45±13.76)mm]和矢状面纵径[(38.75±10.69)mm]均小于有残余组[分别为(61.08±13.73)mm和(53.67±16.05)mm],差异均有统计学意义(Z值分别为-2.455和-2.650,P＜0.05);无残余组低强化区正性积分为0.62±0.25,高于有残余组的0.39±0.14,差异有统计学意义(Z=-2.919,P＜0.05),即病灶越大、低强化区血供越差,则放疗和(或)化疗后易有残余.高强化区最大上升斜率与横断面长径和体积早期变化率有中至强的负相关性(r值分别为-0.577和-0.723,P＜0.05),即MSI越低的病灶在放疗早期退缩越明显.结论 宫颈癌治疗前的DCE在预测放疗结束时病灶是否残余和治疗早期的体积退缩情况等短期治疗效果方面有一定价值.

Potential value of dynamic MR in predicting short-term effects of (chemo-) radiation therapy on cervical cancers

Objective To investigate the potential value of MR dynamic contrast enhanced imaging (DCE)in predicting short-term effects of(chemo-)radiation therapy on cervical cancers in vivo.Methods Thirty-two patients pathologically diagnosed as cervical cancers received MR-DCE scan before therapy.The following scans were taken at the 2nd to 3rd week after the radiation or(and)chemotherapy initiated,to calculate early size change.The fourth scan was performed within one month after the therapy to judge residues.DCE derived parameters include mean time to enhancement(MTE),positive enhancement integral (PEI),time to peak(TTP),maximum slope of increase(MSI)and maximum slope of decrease(MSD).Size and DCE parameters were compared and analyzed by Mann-Whitney test and Spearman teat Results There are 20 cases in non-residue group and 12 cases in residue group.In non-residue group,the maximal lengths in both horizontal and craniocaudal directions[(47.45±13.76)mm and(38.75±10.69)mm]were smaller than that in residue group [(61.08±13.73)mm and(53.67±16.05)mm],with statistical significance(Z=-2.455 and-2.650 respectively,P＜0.05).PEI in low-enhance areas of non-residue group(0.62±0.25)was significantly higher than that in residue group(0.39±0.14)(Z=-2.919,P＜0.05).At early time after radiation started,length changing rate and volume changing rate had medium to strong negative correlations with MSI in hish-enhance areas(r=-0.577 and-0.723 respectively,P＜0.05).Conclusions For cervical cancers,those with larger lengths and lower PEI in low-enhanced areas tend to have tumor residue when radiation therapy completed.Those low MSI in high-enhance areas tend to shrink quickly.It is suggested that volume and parameters of DCE before(chemo-)radiation therapy have the potential in predicting short-term therapeutic effect.