高强度聚焦超声治疗兔肾癌细胞株VX2的CT动态观察

目的 评估CT在高强度聚焦超声治疗兔VX2肾癌近期随访中的价值。方法 纯种新西兰白兔14只，建立原位肾癌动物模型。所有兔行CT检查后随机分成2组：对照组（5只），行高强度聚焦超声（HIFU）假照射，1月后CT检查；治疗组（9只），HIFU治疗后1周、1个月和2个月行CT检查。结果 （1）肿瘤强化：治疗前，所有肿瘤都有强化。对照组肿瘤在假照射后1个月依然都有强化；治疗组在治疗后1周，66．7％的肿瘤强化消失；治疗后1个月，88．9％的肿瘤强化消失；治疗后2个月和1个月相比肿瘤强化无明显变化。（2）肿瘤钙化：治疗后1月，治疗组77．8％的肿瘤出现钙化，对照组肿瘤始终无钙化。（3）肿瘤体积：对照组兔处死前的末次CT检查测得肿瘤体积和解剖后测得肿瘤体积比较，配对t检验，差异无统计学意义（P＞0．05）；同法比较治疗组肿瘤体积，差异无统计学意义（P＞0．05）。（4）治疗前CT测得体积和HIFU治疗点数之间有较好相关性（r=0．667，P＜0．05）。（5）病理观察：治疗后肿瘤细胞凝固性坏死，随访期中示纤维化、钙化改变；未治疗肿瘤生长旺盛。病理和CT结果一致。结论 CT检查可以为制定HIFU治疗计划提供参考；CT可以作为HIFU治疗肾癌后良好的随访手段；CT随访宜在治疗后1个月进行。

Investigation of rabbit VX2 renal tumor treated by high intensity focused ultrasound with following-up contrast CT

Objective To evaluate CT images in following up rabbit VX2 renal tumor treated by HIFU and optimize the time to perform CT scanning.Methods The animals were randomly divided into two groups.The first group was consisted of 9 New Zealand rabbits bearing VX2 renal tumors that were irradiated by HIFU as treated group and the second group was 5 other tumor bearing ones as controls.CT images were used to observe the features of tumors one week,one month and two months after HIFU in treated group respectively.The controls were observed only once.They all were sacrificed in the end of the study and the CT appearances were compared with those of histopathology.Results (1) Enhancement of tumor:All the tumors showed enhancement on contrast CT images before HIFU.No change could be found on CT images of control group after HIFU.In treated group,enhancement disappeared in all the tumors which accounted for 66.7% and 88.9% respectively one week and one month later after treatment.(2) Calcification of tumor:In treated group, 77.8% of tumors showed calcification on CT images one month after treatement and no calcification was found in control group.(3) Tumor volume:Tumor volume measured by CT was compared with pathological analysis using paired T test.There was no significant difference between the treated group and the control group.(4) Treating points of HIFU and tumor volume (measured by CT) had a good correlation (Pearson correlation, r= 0.667, P< 0.05).(5) Pathological analysis:Coagulating necrosis was found in HIFU treated area as well as fibrosis and calcification.The tumors of control group growed up.CT images showed good ralationship with pathological changes.Conclusion CT is a useful method in evaluating the effect of HIFU for rabbit VX2 renal tumor.The CT follow up should be done one month after HIFU treatment.