鼻咽癌放射治疗后FDG PET显像的临床价值

摘要

Objective　To investigate the clinical value of FDG PET imaging in the follow-up of nasopharyngeal carcinoma after radiotherapy. 　Methods　Twelve patients with nasopharyngeal carcinoma underwent FDG PET, CT and/or MRI during the follow-up of 12-18 months after radiotherapy. The results of FDG PET were double-blind evaluated and compared with these of CT and MRI. The recurrent lesions in six of these patients were pathologically confirmed and six by CT scan. 　Results　Nine of 12 patients did not show any recurrence by CT and MRI scans. However, FDG PET scans showed significantly increased FDG metabolism, indicating recurrence in 3 of these patients. In 2 patients, both CT/MRI and FDG PET indicated recurrence. The remaining one patient had radiotherapy induced cerebral necrosis. He was misdiagnozed as an intracranial recurrence by MRI, but FDG imaging was negative. 　Conclusions　FDG PET imaging has an advantage in distinguishing the relapse or necrosis in the follow-up of post-radiotherapy nasopharyngeal carcinoma patients. PET, CT and MRI is able to give a detail both in morphological and functional changes of disease. They are especially useful in the follow-up or the set-up of treatment planning for recurrent nasopharyngeal carcinoma.%目的　探讨核医学影像诊断技术─FDG PET在鼻咽癌放射治疗后随诊中的临床价值。方法　12例鼻咽癌患者放射治疗后12～18个月同期行FDG PET和CT、MRI检查，并采用双盲法将FDG PET与CT和MRI结果进行比较，其中6例经活检病理证实，余6例经CT动态观察10个月后确诊。结果　9例CT和MRI未见肿瘤复发，PET显示其中3例有局灶性FDG代谢明显增高病变，2例CT和MRI 提示肿瘤复发，FDG PET均显示局部病变有放射性摄取浓聚；该5例FDG摄取浓聚的病变处均经活检病理证实为肿瘤复发。另1例MRI提示鼻咽癌颅内转移，而FDG PET诊断为放射治疗后脑损伤，后经CT随访证实。结论　与CT和MRI检查相比，FDG PET在鼻咽癌放射治疗后肿瘤复发的早期定性诊断上具有明显的优势，若结合CT和MRI多种影像结果分析，更能提供局部病变结构与代谢改变的复合信息，尤其对局部复发病灶精确的适形放射治疗非常重要。