18F-FDG符合线路显像检测甲状腺癌转移灶的价值

目的　比较18F 脱氧葡萄糖 (FDG)双探头符合线路SPECT(DHCI)与PET显像检测甲状腺癌转移病灶的价值。方法　 2 6例甲状腺癌患者在同 1天分别进行了18F FDGPET和18F FDGDHCI显像 ,患者均已行甲状腺切除术和131I治疗。肿瘤转移病灶大小由计算机自动勾边在PET显像图中测定。结果　 2 6例甲状腺癌患者中 ,18F FDGPET共发现 12 6个肿瘤转移病灶 ,其中18F FDGDHCI检测到 92个 (73 % ) ,CT发现 76个 (6 0 % ) ,18F FDGDHCI的病灶检测率明显高于CT(P <0 0 5 )。根据病灶部位分析 ,18F FDGDHCI与PET对转移病灶检测的符合率在头颈部为 6 8% ,胸部为 83% ,而在骨转移病灶的符合率仅为 5 2 % (P <0 0 1)。根据病灶大小分析 ,当肿瘤转移病灶大于 1 5cm时 ,18F FDGDHCI与PET结果的一致率达 98% ;而在 1～ 1 5cm的病灶检测中 ,18F FDGDHCI仅能发现 5 6 % ;当病灶小于 1cm时 ,18F FDGDHCI则难以发现 ,而PET发现的病灶最小直径为 0 7cm。结论　当肿瘤转移病灶的直径大于 1 5cm时 ,18F FDGDHCI与PET具有相似的诊断准确性。

Value of dual-head coincidence 18 F-FDG imaging on detecting metestases of thyroid cancer:comparison with 18 F-FDG PET imaging

Objective　To compare the value of dual head coincidence imaging (DHCI) and PET 18　F-FDG imaging for detection of thyroid metastatic cancer. Methods　 26 patients with thyroid cancer were examined by both PET and DHCI 18　F-FDG imaging on same day after thyroidectomy and radioiodine ablation. The size of tumor lesion was derived from the PET images applying a 50% intensity isocontour by automatic computer outlining. Results　18F-FDG PET imaging find 126 lesions in 26 patients, whereas DHCI was 92(73%) and CT was 76(60%). Analysis of different anatomical areas showed that the concordence in the head and neck was 68%, chest 83%, and only 52% in bone metastases. Analysis based on the size of lesions showed that 98% of lesions larger than 1.5 cm, can be detected both by DHCI and PET, but only 56% of the lesions between 1～1.5 cm can be detected by DHCI. If the lesion below 1 cm, it can hardly find by DHCI. The smallest lesion seen by the PET was 0.7 cm in diameter. Conclusion　There was similar accuracy for detecting metastases of thyroid cancer larger than 1.5 cm with both DHCI and PET.