用^(18)F-FDG PET显像评价恶性肿瘤射频消融术疗效

Clinical application of FDG PET to evaluate the therapeutic efficacy of radiofrequency ablation in tumor patients

目的 探讨用1 8F 脱氧葡萄糖 (FDG)PET显像评价射频消融术治疗肺、肝恶性肿瘤疗效的可行性。方法 肺和肝脏恶性肿瘤患者 2 2例行射频消融术治疗。其中单发病灶 10例 ,多发病灶 12例。治疗前、后各行 1次PET显像者 10例 ,仅治疗后行PET显像者 12例。临床随访时间 6个月～ 2年。结果 ① 2 2例患者共 38个病灶 ,射频消融术治疗野内皆可见放射性缺损灶 ,经CT、X线胸片随访证实缺损灶为坏死组织。 12例PET显像发现有 15个缺损灶边缘存在环形或弧形放射性浓聚灶 ,影像学随访和病理检查证实 9例 12个缺损灶边缘有残余恶性肿瘤 ,余 3例 3个缺损灶边缘浓聚影为炎症反应。边缘肿瘤残余病灶的标准摄取值 (SUV)明显高于炎症反应 (6 .96 5± 2 .72 6对 2 .6 0 7±0 6 90 ,P <0 .0 5 )。②治疗前后各行 1次PET显像者 10例 ,14个治疗病灶治疗前见1 8F FDG高度浓聚 ,治疗后治疗野呈放射性缺损 ,SUV分别为 7.932± 3.130和 0 .70 6± 0 .2 97(P <0 .0 0 1)。未行消融术治疗病灶 9个 ,第 2次显像病灶浓聚程度稍增高 ,SUV分别为 5 .95 2± 1.92 7和 5 .2 5 7± 1.932 (P >0 .0 5 )。③ 13例治疗后 2周内行CT检查与PET显像比较 ,治疗后CT皆示病灶较治疗前增大 ,肺内病灶密度改变不明显 ,2例肝癌病灶密度改变 ,而PET显像?

Objective To analyse the characteristics of 18 F FDG PET images of the patients with tumors treated with radiofrequency ablation, and to assess the clinical feasibility of PET for evaluating the effect of the therapy. Methods Twenty two patients with tumors in lung or (and) in liver treated with radiofrequency ablation were studied. Among them, 10 cases had single lesion, and 12 cases had multiple lesions. In 10 cases, the PET scan was performed both before and after therapy. In the remaining 12 cases, the PET scan was only performed after therapy. All cases were followed up for 6 months to 2 years. Results ①Among them, 38 lesions were treated with radiofrequency ablation. After treatment, the defect zones in treated area could be found in PET images of all patients, and they all were proved to be necrotic tissue by following up. Fifteen hypermetabolic images with the shape as loop or arc were seen at the margin of defect zones after therapy in 12 cases. Twelve hypermetabolic images were proved to be the residual tumors in 9 cases and 3 hypermetabolic images to be the inflammatory foci in 3 cases by following up and pathology examination. The standardized uptake value (SUV) of the residual tumors were higher than that of the inflammatory tissue (6.965±2.726 vs 2.607±0.690, P <0.05). ②PET scan was performed twice in 10 cases, before and after therapy, for comparison. Among them,14 lesions were treated with radiofrequency ablation. Before therapy, focal hypermetabolic images were seen in all tumors, but disappeared after therapy, and were replaced by the defect zone in the treated area. The change of the SUV was dramatically (7.932±3.130 vs 0.706±0.297, P <0.001). Nine lesions were not treated with radiofrequency ablation for some specific reasons, the uptakes of 18 F FDG of the tumors increased slightly on the second scanning. The post therapy SUV was significantly higher, 5.952±1.927, comparing to 5.257±1.932 pretherapy ( P >0.05). ③The CT scan was also performed on 13 cases within two weeks after therapy in order to compare with the PET. After therapy, the CT images showed the area of lesions enlarged by contraies. The lesion density in lung showed no obvious changes and the lesion density in liver changed in 2 cases with primary liver cancer, but the defect zones showed obviously in the PET images of all these 13 cases. Conclusions 18 F FDG PET scan can identify necrosis and residual tumor easily and accurately. It is an excellent imaging modality for evaluation of early therapeutic efficacy of radiofrequency ablation and is superior to the CT scan.