Sharma Amita, Lanuti Michael, He Wei, Palmer Edwin L, Shepard Jo-Anne O, Digumarthy Subba R
Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114, USA.
J Comput Assist Tomogr. 2013 Jan-Feb;37(1):9-14. doi: 10.1097/RCT.0b013e3182732341.
The objective of this study was to evaluate the F-fluorodeoxyglucose positron emission tomography (F-FDG-PET) findings following complete radiofrequency ablation (RFA) treatment of malignant lung tumors.
Follow-up PET and computed tomography examinations in 18 patients (mean age, 67 ± 16 years [range, 30-91 years]; 10 males, 8 females) who underwent 19 RFA sessions for the treatment of primary (n = 14) and metastatic (n = 5) lung tumors with mean follow-up of 18 months (range, 12-24 months) were retrospectively reviewed by 2 thoracic radiologists. All tumors were completely ablated. The maximum standardized uptake value (SUV) of the tumor and surrounding lung at baseline and at 1, 6, 12 and 24 months after RFA was measured. In addition, the size, histology, location of the tumor, presence of underlying emphysema, electrode type, and complications from RFA were recorded. Data were analyzed using Fisher exact test.
Baseline tumor SUV was variable (mean, 1.8 ± 1.5 [range, 0.7-7]). The post-RFA F-FDG-PET appearances could be divided into 2 groups. A ring of peripheral activity and central photopenia was seen following 13 (68%) of 19 of ablations, and no ring was noted following 6 (32%) of 19 of ablations. The ring of F-FDG-PET activity was present at 1 month in 62%, at 6 months in 69% and at both 1 and 6 months in 31%. In all cases, central photopenia at 1 or 6 months was replaced by increased activity as the ring resolved at 6 or 12 months, mimicking local tumor progression. The presence of a ring of activity was associated with the use of a cluster electrode (P = 0.01). Lesion size, histology, location, baseline SUV, electrode type, or development of cavitation following RFA were not significantly associated with a post-RFA ring (P > 0.05) on PET scans. At 12 or 24 months, the SUV in the center of the lesion was equal to or greater than the SUV at baseline in 9 (47%) of 19 cases.
Recognition of the normal FDG-PET appearances after RFA is important to prevent misdiagnosis of local tumor progression.
本研究的目的是评估恶性肺肿瘤完全射频消融（RFA）治疗后的氟脱氧葡萄糖正电子发射断层扫描（F-FDG-PET）结果。
2名胸放射科医生对18例患者（平均年龄67±16岁[范围30 - 91岁]；男性10例，女性8例）进行回顾性研究，这些患者接受了19次RFA治疗原发性（n = 14）和转移性（n = 5）肺肿瘤，平均随访18个月（范围12 - 24个月）。所有肿瘤均被完全消融。测量了基线时以及RFA后1、6、12和24个月时肿瘤及周围肺组织的最大标准化摄取值（SUV）。此外，记录了肿瘤的大小、组织学类型、位置、潜在肺气肿的存在、电极类型以及RFA的并发症。使用Fisher精确检验分析数据。
基线肿瘤SUV各不相同（平均值为1.8±1.5[范围0.7 - 7]）。RFA后的F-FDG-PET表现可分为两组。19次消融中有13次（68%）出现外周活性环和中央放射性缺损，19次消融中有6次（32%）未观察到环。F-FDG-PET活性环在1个月时出现的占62%，在6个月时出现的占69%，在1个月和6个月时均出现的占31%。在所有病例中，1或6个月时的中央放射性缺损在6或12个月时随着环的消失被活性增加所取代，类似局部肿瘤进展。活性环的出现与使用集束电极有关（P = 0.01）。病变大小、组织学类型、位置、基线SUV、电极类型或RFA后空洞的形成与PET扫描上RFA后的环无显著相关性（P > 0.05）。在12或24个月时，19例中有9例（47%）病变中心的SUV等于或大于基线时的SUV。
认识RFA后正常的FDG-PET表现对于防止误诊局部肿瘤进展很重要。
