^18FDG PET在鼻咽癌放疗后鼻咽部复发或残留再程三维适形放疗中的临床价值

目的 探讨^18氟-脱氧葡萄糖正电子发射断层扫描仪（^18FDG PET）在鼻咽癌放射治疗后鼻咽部复发或残留再程三维适形放射治疗（3DCRT）中的临床应用价值。方法 对36例首程放射治疗后鼻咽部复发或残留的鼻咽癌患者．采用CT模拟定位，结合^18FDG PET确定靶区范围，应用三维适形放射治疗，观察CT与^18FDG PET确定靶区大小的差异、疗效和并发症。结果 36例患者中，^18FD GPET较CT而言，大体肿瘤体积大小无变化的占36．1％（13／36）、增加的占16．7％（6／36）、缩小的占47．2％（17／36）。1、2、3年局部控制率分别为97.2％、75．0％、58.3％；1、2、3年生存率分别为94．4％、86．1％、72．0％；1、2、3年无瘤生存率分别为85．7％、76．6％、56．1％。急性放射反应主要是急性放射性口咽、鼻咽粘膜炎和口干，多为Ⅰ～Ⅱ级。晚期放射损伤包括听力丧失5．6％（2／36）、张口困难25．0％（9／36）、吞咽困难8．3％（3／36）、慢性副鼻窦炎33．3％（12／36）、脑神经损伤13．9％（5／36）。结论 三维适形放射治疗结合^18FDG PET确定靶区范围在鼻咽癌放射治疗后鼻咽部局部复发或残留中有较好的疗效，同时由于靶区缩小而使放射损伤发生率降低。

Value of ^18F-fluorodeoxyglucose positron emission tomography in three-dimensional conformal radiotherapy for locally persistent or recurrent nasopharyngeal carcinoma

OBJECTIVE: To explore the clinical value of (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) in three-dimensional conformal radiotherapy (3D-CRT) for locally residual and recurrent nasopharyngeal carcinoma (NPC). METHODS: Between July 1998 and October 2000, 36 patients with recurrent or residual NPC confirmed by biopsy after initial radiotherapy underwent treatment with 3D-CRT. CT simulation was performed and (18)FDG-PET carried out for delineating the gross tumor volume (GTV) in all the patients. The radiotherapy was designed by 3D treatment planning system and dose-volume histogram (DVH) was used to verify and optimize the radiation plan. Acute and late radiation injuries, survival rates and GTV delineated by CT and (18)FDG-PET were observed in all the cases after the treatment. RESULTS: In comparison with CT simulation, (18)FDG-PET delineated similar GTV in 36.1% (13/36) cases, larger and smaller GTV in 16.7% (6/36) and 47.2% (17/36) of the cases, respectively. After 3D-CRT, 97.2%, 75.0%, and 58.3% of the patients were free of evidence of 1-, 2-, and 3-year local failure, respectively, and the 1-, 2-, and 3-year survival rate of the patients were 94.4%, 86.1%, and 72.0%. The 1-, 2-, 3-year tumor-free survival rates were 85.7%, 76.6%, and 56.1% respectively. Acute xerostomia, nasopharyngitis and oropharyngitis were the most common complications in relation to the radiation, but all within acceptable range of grades 1 or 2. The lesions resulting from the radiation included hearing loss, trismus, dysphagia, chronic sinusitis, and cranial neuropathy, with the incidences of 5.6% (2/36), 25.0% (9/36), 8.3% (3/36), 33.3% (12/36), and 13.9% (5/36) respectively. CONCLUSIONS: 3D-CRT combined with (18)FDG-PET for delineation of GTV is effective and feasible in the treatment of locally residual or recurrent nasopharyngeal carcinoma after initial radiotherapy, producing good responses without serious complications.