Dietlein M, Scheidhauer K, Voth E, Theissen P, Schicha H
Department of Nuclear Medicine, University of Cologne, Germany.
Eur J Nucl Med. 1997 Nov;24(11):1342-8. doi: 10.1007/s002590050158.
Metastases of differentiated thyroid cancer may show different uptake patterns for fluorine-18 fluorodeoxyglucose and [131I]NaI. FDG positron emission tomography (PET), iodine-131 whole-body scintigraphy (131I WBS) and magnetic resonance imaging were performed in 58 unselected patients, and spiral computed tomography (CT) of the lung in 25 patients. Thirty-eight patients presented with papillary carcinomas, 15 patients with follicular carcinomas and five patients with variants of follicular carcinoma. Primary tumour stage (pT) was pT1 in 3, pT2 in 19, pT3 in 11 and pT4 in 25 cases. For the detection of metastases, FDG PET was found to have a sensitivity of 50%, 131I WBS a sensitivity of 61%, and the two methods combined a sensitivity of 86%. When FDG PET was limited to patients with elevated thyroglobulin (Tg) levels and negative 131I WBS, the sensitivity of this algorithm was 82%. Of the 21 patients with lymph node metastases, seven presented with FDG uptake but no iodine uptake. In four of them, a second FDG hot spot appeared in a lymph node metastasis of normal size. Five of the seven patients underwent surgery. None of the eight patients with pulmonary metastases smaller than 1 cm exhibited FDG uptake, while five of them had iodine uptake. All had positive results on spiral CT. In conclusion, FDG PET cannot be substituted for 131I WBS. If the Tg level is elevated and 131I WBS is negative, FDG PET can be used to detect lymph node metastases and complements anatomical imaging. A spiral CT of the lung is useful to exclude pulmonary metastases before planning a dissection of iodine-negative lymph node metastases.
分化型甲状腺癌的转移灶对氟-18氟脱氧葡萄糖和[131I]碘化钠可能呈现不同的摄取模式。对58例未经筛选的患者进行了氟代脱氧葡萄糖正电子发射断层扫描（FDG PET）、碘-131全身闪烁扫描（131I WBS）和磁共振成像检查，对25例患者进行了肺部螺旋计算机断层扫描（CT）。38例患者为乳头状癌，15例为滤泡状癌，5例为滤泡状癌变体。原发肿瘤分期（pT）：pT1期3例，pT2期19例，pT3期11例，pT4期25例。对于转移灶的检测，发现FDG PET的敏感性为50%，131I WBS的敏感性为61%，两种方法联合使用的敏感性为86%。当FDG PET仅限于甲状腺球蛋白（Tg）水平升高且131I WBS阴性的患者时，该算法的敏感性为82%。在21例有淋巴结转移的患者中，7例表现为FDG摄取但无碘摄取。其中4例在正常大小的淋巴结转移灶中出现第二个FDG热点。7例患者中有5例接受了手术。8例肺转移灶小于1 cm的患者均未表现出FDG摄取，而其中5例有碘摄取。所有患者螺旋CT检查结果均为阳性。总之，FDG PET不能替代131I WBS。如果Tg水平升高且131I WBS阴性，FDG PET可用于检测淋巴结转移并补充解剖成像。在计划对碘阴性淋巴结转移灶进行清扫之前，肺部螺旋CT有助于排除肺转移。
