氩氦刀治疗肝细胞癌早期疗效的MRI评价

MRI evaluation of the early effect of argon-helium cryoablation therapy for patients with hepatocellular carcinoma

目的探讨氩氦刀冷冻消融术治疗肝细胞癌(hepatocellular carcinoma,HCC)早期疗效的MRI特征。方法应用氩氦刀治疗53例HCC患者的59个病灶,并回顾性分析治疗前后的MRI图像,评价早期疗效,探讨肿瘤完全坏死和残留的MRI特点。结果治疗后59个病灶中41个(69.5%)完全坏死,18个(30.5%)肿瘤残留。术后3～7d(A组)、4～6周(B组)及12～15周(C组)复查MRI评估疗效,疗效评估诊断(完全坏死/肿瘤残留)分别为36/23、39/20、40/19,3组疗效评估结果一致。氩氦刀治疗后早期(A组)T1加权像(T1weightedimage,T1WI)消融区低信号、瘤结节高信号及瘤周0.5cm消融边界为肿瘤坏死完全的可靠征象,T2加权像(T1weightedimage,T2WI)消融区呈环形且厚度均匀的高信号为炎性反应。T2WI消融区局灶性高信号及增强扫描不规则强化仍是诊断肿瘤残留的"金标准"。结论 MRI评价氩氦刀治疗HCC的早期疗效具有及时、准确、特异性高、无辐射的优点,术后3～7d即可进行早期评价。T1WI具有较高的诊断价值,T2WI信号及增强扫描仍是评价疗效的关键。

Objective To investigate the magnetic resonance imaging （MRI） findings in evaluating the early effect of argonhelium cryoablation therapy for hepatocellular carcinoma （HCC）. Methods Fifty-nine lesions in 53 HCC patients were given argonhelium cryoablation therapy. MRI findings before and after therapy were retrospectively analyzed for evaluating early therapeutic ef- fect and investigating the MRI features of complete tumor necrosis and residual tumor. Results After argon-helium cryoablation therapy, complete inactivation was found in 41 of 59 （69.5%） lesions and partial necrosis in 18 （30.5%） lesions. MRI examination was made 3-7 days （group A）, 4-6 weeks （group B） and 12-15 weeks （group C） after therapy for the evaluation of the therapeutic effect. The number of complete tumor necrosis and residual tumor were 36 and 23 in group A, 39 and 20 in group B and 40 and 19 in group C. The therapeutic effects of the 3 groups were not significantly different. The findings with low signal intensity of cryoablation zone, high signal intensity of the nodules and 0.5 em safety margin were the definite signs of complete tumor necrosis on T1 weighted image （T1WI）. The inflammatory response showed annular high signal intensity of eryoablation zone on T2 weighted image （T2WI）. The focal high signal and irregular contrast enhancement around the eryoahlation edge were the gold standard for the diagnosis of residual tumor. Conclusions The evaluation on early effect of argon-helium cryoablation therapy for HCC according to MRI finding is timely, accurate, specific and free of radiation. Early effect can be evaluated 3-7 days after argon-helium eryoablation therapy. T1W1 is of high diagnostic value, and T2W1 signal and contrast-enhanced scan are crucial for the evaluation of therapeutic effect.