^(18)F-FDG PET/CT早期监测小剂量顺铂在体化疗敏感性的实验研究

Early in vivo monitoring chemosensitivity to low dose cisplatin of VX2 xenografts in rabbits by ^(18)F-FDG PET/CT

42只双侧前胸壁荷瘤的VX2兔模型(共计84个肿瘤)随机分为治疗组(n=32)和对照组(n=10)。治疗组静脉给予4mg/kg顺铂前(Pre-therapy)和给药后95–100min(Day0)、Day1、Day7、Day14行PET/CT显像;对照组不给化疗药物,其余与实验组相同。取葡萄糖摄取最大值(SUVmax)进行分析,CT测量肿瘤大小。按肿瘤体积分组,Day7时治疗组肿瘤体积增长>1倍则为不敏感,反之为敏感。结果显示:(1)Day0敏感组SUVmax减低率为(?48.96±12.27)%,而不敏感组和对照组为(21.26±18.26)%和(7.16±13.47)%,三组SUVmax变化有显著差异(P<0.05)。(2)Pre-therapy、Day0、Day1、Day14两组肿瘤体积无显著性差异(P>0.05),但Day7敏感组肿瘤体积小于不敏感组及对照组,差异有显著性(P<0.05)。(3)Day7、Day14敏感组肿瘤坏死率大于不敏感组及对照组,差异有显著性(P<0.05)。(4)HE染色观察不同时间点切除的肿瘤标本发现:Day7、Day14时敏感组肿瘤细胞数少而炎性和坏死细胞数增加。表明根据化疗药物给予后FDG减低程度,18F-FDGPET/CT能在体、早期、灵敏检出肿瘤对化疗药物的敏感性。

This study is to explore the feasibility of using ^18F-FDG PET/CT as an in vivo individual chemosensitivity testing method. Forty-two VX2 rabbits bearing a total of 84 tumors were randomized into treatment group （n=32） and control group （n=10）. ^18F-FDG PET/CT was performed the day before intravenous administration of cisplatln （4 mg/kg） and at 95-100 min （Day 0）, Day 1, Day 7, and Day 14 afterward. The control group, without cisplatin administration, received the ^18F-FDG PET/CT imaging at the same time points. Maximum standardized uptake value （SUV） was analyzed. The animals on Day 7 with a tumor volume of at least twice as larger than Day 0, were regarded as the sensitive group （SG）, while the others the insensitive group （ISG）. The results showed that a significant difference （P〈0.05） in SUV on Day 0 between SG and ISG with SUV decrease rate of （-48.96±12.27）%, （21.26±18.26）% and （7.16±13.47）% for SG ISG and the control, respectively. No significant difference in tumor volume was found among the three groups pre-therapy and on Day 0 and Day 1. On Day 7, however, the tumor volume with SG was smaller than with ISG, in a significant difference of P〈0.05, while no significant difference was seen between ISG and the control on Day 7. On Day 14, no significant difference was observed among the tumor volume of the three groups （P〉0.05）. On Day 7 and Day 14, significant differences were seen in tumor necrosis rate in SG and ISG （P〈0.05）, but no significant differences were seen between ISG and the control. Paraffin section stained with haematoxylin and eosin of sections obtained at different time showed that the number of viable tumor cells in sensitive group diminished than ISG and the control, and inflammation and necrotic cells were increased on Day 7 and Day 14. The study showed that ISF-FDG PET/CT can be used as an in vivo chemosensitivity testing method. According to the decrease rate when cisplatin adminstration, PET can early in vivo sensitively differentiate the sensitive and insensitive tumors.