^(13)N-NH_3 PET显像诊断星形细胞瘤

^(13)N-NH_3 PET in the diagnosis of astrocytomas:preliminary result

目的 探讨13 N NH3 PET显像诊断星形细胞瘤的可行性。方法 7例星形细胞瘤患者 ,包括术前星形细胞瘤 3例 ,术后复发 2例 ,术后放疗后脑损伤或坏死 2例。 7例中 6例在 2d内完成13 N NH3 和18F 脱氧葡萄糖 (FDG)PET显像 ,1例仅行13 N NH3 显像。采用对称感兴趣区 (ROI)方法分析肿瘤与正常脑白质 (T WM)的13 N NH3 、18F FDG的摄取比值。结果 3例术前星形细胞瘤和 2例术后复发肿瘤病灶均明显摄取13 N NH3 ,T WM平均为 1 82± 0 2 1,其中 1例术后病理检查为星形细胞瘤Ⅰ级患者 ,18F FDGPET显像示局部病变区放射性分布明显减低 ,T WM为 0 97,相应位置13 N NH3 显像呈高代谢 ,T WM为 1 98。 2例术后放疗后脑损伤或坏死患者13 N NH3 及18F FDGPET显像均示局部病变区为放射性分布缺损或明显减低。结论 星形细胞瘤摄取13 N NH3 ;13 N NH3 PET显像对星形细胞瘤术前诊断。

Objective To evaluate the feasibility of diagnosing the astrocytomas with 13 N-NH 3 PET imaging. Methods 13 N-NH 3 and 18 F-fluorodeoxyglucose (FDG) PET imaging were performed in seven cases of astro cytomas including 3 anteoperative astrocytomas, 2 recurrent astrocytomas, 2 brai n injury o r necrosis after the operation and radiotherapy. The radioactivity ratios of the tumor and normal white matter (T/WM) were calculated. Results The tumor lesions in 3 anteoperative astrocytomas and 2 recurrent astrocytomas a ll uptake 13 N-NH 3. The average T/WM on 13 N-NH 3 images was 1.82±0.21, and T/WM on 13 N-NH 3 and 18 F-FDG images were 1.98 and 0.97 for one case with grade 1 astrocytoma. 13 N-NH 3 and 18 F-FDG PET imaging both showed decreased up take in 2 brain injury or necrosis after the operation and radiotherapy of astro cytomas. Conclusions 13 N-NH 3 was uptaken in astrocytomas. 13 N-NH 3 can be useful in the diagnosis of astrocytoma, and potentially improve diagnostic accuracy of astrocytoma, esp ecially in low-grade astrocytoma.