99Tcm-MIBI显像用于分化型甲状腺癌复发与P-gp表达的关系研究

目的 探讨分化型甲状腺癌(DTC)手术及131I清除剩余甲状腺组织(清甲)后复发时99Tcm-甲氧基异丁基异腈(MIBI)显像的特点及耐药蛋白(P-糖蛋白,P-gp)的表达.方法 经手术病理检查确诊为DTC、清甲治疗后患者173例,术前均行99Tcm-MIBI双时相甲状腺局部静态显像,图像由3位有经验的核医学科医师集体阅片,计算99Tcm-IBI显像早期(10 min)、延迟(120 min)肿瘤/正常组织放射性(T/NT)比值及洗脱率,术后4-6周行清甲.3年内复发9例为复发组,单纯随机抽样法选择未复发病例9例为无复发组.选取术后癌组织保存标本,采用免疫组织化学法及反转录-聚合酶链反应(RT-PCR)技术检测P-gP的表达.统计学处理采用SPSS 10.0软件,行t检验及Spearman秩相关分析.结果 DTC复发组早期、延迟相T/NT比值及洗脱率分别为1.18±0.28,1.16±0.24和(17.00±2.91)%,无复发组分别为1.54±0.26,1.65±0.26和(7.130±3.21)%,差异均有统计学意义(t=2.835,4.152,6.924,P均<0.01);DTC组织中P-gp的阳性细胞数比率复发组为(43.00±8.21)%,明显高于无复发组的(26.00±6.91)%(t=4.753,P<0.01),不同病理类型间阳性细胞数比率差异无统计学意义(t=0.176,P>0.05);DTC组织中P-gp的基因表达量复发组为0.60±0.12,明显高于无复发组的0.31±0.19(t=3.871,P<0.01),不同病理类型DTC的P-gp基因表达量差异无统计学意义(t=0.337,P>0.05).免疫组织化学及RT-PCR结果均提示:DTC患者癌组织中的P-gp表达与99Tcm-MIBI显像洗脱率之间均存在直线正相关(r=0.84和0.79,P均<0.05).结论 99Tm-MIBI显像早期、延迟T/NT比值及洗脱率与DTC清甲后复发关系密切,DTC原发灶清除99Tcm-MIBI的能力可在体反映P-gp的活性,原发灶99Tcm-MIBI的洗脱率可以预测其术后复发.

Relationship between 99Tcm-MIBI imaging and P-gp expression in patients with recurrent differential thyroid carcinoma

Objective The aim of this study was to evaluate the relationship between 99Tcm-me-thoxyisobutylisonitrih (MIBI) imaging and P-glycoprotein (P-tip) expression in patient with recurrent dif-ferentiated thyroid carcinoma (DTC) after primary definitive thyroidectomy and adjuvant 131I ablation after operation. Methods A total of 173 pathologically confirmed DTC patients were included. All had two-phase 99gTcm-MIBI static imaging preoperatively. Both early (10 min after intravenous injection) and delayed (120 min after intravenous injection) 99gTcm-MIBI tumor/non-tumor (T/NT) ratios and wash-out rates were calculated. Imaging results were analyzed by three experienced nuclear medicine physicians. At the time of follow-up (three years after diagnosis), nine (5.20%) had local tumor recurrence. Nine non-recurrent disease patients were randomized selected as controls. The postoperative carcinoma tissue specimens were obtained to detect P-gp expression through immunohistochemical staining and RT-PCR technique. T test and Spearman correlation were done with SPSS 10.0. Results In recurrent group, the early and late T/NT ra-tios and wash-out rates were 1.18±0.28, 1.16±0.24, and (17.00±2.91 )%. In non-recurrent group, the early and late T/NT ratios and wash-out rates were 1.54±0.26, 1.65±0.26, and (7.00±3.21) %.Statistically higher P-gp positive cell number and P-gp gene expression were noted in recurrent than in non- recurrent groups [(43.00±8.21)% vs (26.00±6.91)%, t =4.753, P<0.01 and 0.60±0.12 vs 0.31±0.19, t=3.871, P<0.01). Moreover, positive correlation was noted between P-gp expression and 99Tcm-MIBI wash-out rate among DTC patients (r=0.84, P<0.05 and r=0.79, P < 0.05). Conclusions P-gp expression was positively correlated with 99gTcm-MIBI wash-out rate among DTC patients and was signif-icantly higher in recurrent than in non-recurrent groups, which might be due to higher P-gp positive cell number in recurrent than in non-recurrent groups.