Hung Guang-Uei, Tsai Shih-Chuan, Lin Wan-Yu
Department of Nuclear Medicine, Changhua Christian Hospital, Changhua, Taiwan.
Clin Nucl Med. 2005 Aug;30(8):558-9. doi: 10.1097/01.rlu.0000170039.14351.0b.
A false-positive F-18 FDG PET scan caused by osteoradionecrosis and inflammation in patients with nasopharyngeal carcinoma (NPC) has been reported. The standard uptake values (SUVs) in these false-positive cases are always below 6 and decrease with time. This report is concerned with a false-positive result with extraordinarily high F-18 FDG uptake, which increased on the delayed 3-hour image. A 63-year-old man with NPC underwent surgical removal and radiotherapy (7400 cGy) in July 2003. In October 2003, the CT scan showed a large soft tissue mass over the nasopharynx. Tumor recurrence was suspected. F-18 FDG PET scan showed an FDG-avid lesion over the nasopharyngeal region with a maximum SUV of 28.8 at 1 hour that increased to 30.4 at 3 hours. Biopsy was performed and the histopathologic examination showed only necrotic tissue and no evidence of tumor cells. Radiation necrosis was diagnosed. No evidence of tumor recurrence was noted during the 10-month follow-up period.
据报道，鼻咽癌（NPC）患者可因放射性骨坏死和炎症导致F-18 FDG PET扫描出现假阳性结果。这些假阳性病例的标准摄取值（SUV）通常低于6，且随时间下降。本报告关注的是一例F-18 FDG摄取异常高的假阳性结果，该结果在延迟3小时图像上有所增加。一名63岁的鼻咽癌男性患者于2003年7月接受了手术切除及放疗（7400 cGy）。2003年10月，CT扫描显示鼻咽部有一个大的软组织肿块。怀疑肿瘤复发。F-18 FDG PET扫描显示鼻咽部区域有一个FDG摄取活跃的病灶，1小时时最大SUV为28.8，3小时时增至30.4。进行了活检，组织病理学检查仅显示坏死组织，未发现肿瘤细胞证据。诊断为放射性坏死。在10个月的随访期内未发现肿瘤复发迹象。
