肿瘤非手术治疗后FDG PET随访的临床价值

目的　探讨 FDG PET影像诊断在肿瘤非手术治疗后临床随访中的价值。　方法　选择实质性肿瘤高强度聚焦超声 (HIFU)治疗后 2 1例 ,鼻咽癌患者放射治疗后 14例 ,共 35例 ,随访中同期行 FDG PET和 CT、MRI检查 ,并将结果进行双盲比较。　结果　 2 1例实质性肿瘤 HIFU治疗后 2～ 3个月复查 ,19例 CT、MRI表现密度和信号有变化 ,但形态、大小未见明显改变 ,另 2例 CT、MRI密度和信号变化不明显 ;PET示 17例肿瘤中心大部分放射性分布缺损 ,但以肿瘤边缘部分为主仍有 FDG代谢活跃现像 ,提示部分肿瘤存活 ,其中 6例在 FDG代谢活跃局部经穿刺活检证实肿瘤存活 ;4例 PET表现为 FDG摄取缺损 ,其中 1例局部穿刺活检证实为坏死组织。 14例鼻咽癌放疗后 12～ 18个月复查 ,CT和 MRI提示 11例未见局部肿瘤复发 ,PET显示其中 3例有局灶性 FDG浓聚病变 ,其中 1例局部穿刺活检证实为局部肿瘤复发 ;2例 CT和 MRI提示肿瘤复发 ,FDG显像病变处有明显的放射性浓聚 ;余 1例放射治疗后脑损伤 FDG PET显示为放射性分布缺损区。　结论　 FDG显像在实质性肿瘤 HIFU治疗后疗效判断和鼻咽癌放射治疗后肿瘤复发诊断上较 CT和 MRI准确 ,两者结合分析在临床随访中更具有明显的优势

Clinical value of FDG PET imaging in monitoring non-operative treatment effects for malignant tumors

Objective To discuss the clinical value of nuclear imaging techniques (FDG PET) to monitor and to define residue or recurrences tumors from non operative treatment for solid malignant tumors and nasopharyngeal carcinoma. Methods 21 cases of abdominal solid tumors treated by high intensity focused ultrasound (HIFU) and 14 cases of post radiotherapy nasopharyngeal carcinoma were imaged using FDG PET, CT and/or MRI in same period. The results of FDG PET were prospectively evaluated and compared with CT and MRI. Results In group of solid tumors treated by HIFU, CT or MRI showed remarkably density or intensity changing without decreased in tumor size in 19 cases. But on FDG PET scans, there were dense FDG uptake in some center or peripheral zone of tumor which indicating partial tumor residue in 17 cases. Other 4 cases of totally necrosis were diagnosed by FDG PET after HIFU, in which CT showed no remarkably changes, based on FDG metabolism. In group of post radiotherapy nasopharyngeal carcinoma, FDG PET scans depicted 3 cases of tumor recurrences in 11 patients, in which CT or MRI showed no remarkably abnormalities, based on significantly increased FDG metabolism. And in other 2 cases of tumor recurrences, CT or MRI and FDG PET had consonant results. Another one case of post radiotherapy cerebral necrosis missed as tumor intracranial involvement on MRI showed FDG uptake defect at all. Conclusion FDG PET has demonstrated powerful advantages in characterizing and monitoring lesions for differentiating recurrent disease from treatment effects in abdominal solid tumors treated by HIFU and post radiotherapy nasopharyngeal carcinoma.