Kraft Otakar
Department of Nuclear Medicine, University Hospital, Ostrava-Poruba.
Nucl Med Rev Cent East Eur. 2005;8(1):44-6.
Differentiated thyroid cancers (DTC) often form metastases in neck lymph nodes, lungs and bones. Other metastases--to the brain, kidneys, skin and liver are rare. Liver metastases of DTC occur in the terminal phase of the disease and predominantly do not accumulate radioiodine. Functional (accumulating radioiodine) metastases are very rare.
In an 85 year old patient with DTC of the follicular type after removal of the thyroid and lymph nodes metastases on the neck and after the elimination of thyroid remnants by radioiodine, a functional metastasis in the liver was detected by combination of whole-body scintigraphy following administration of 131I and liver scintigraphy by using 99mTc-colloid, supplemented by bone scintigraphy after administration of 99mTc-MDP. At first, the high thyroglobulin serum level was falsely negative after repeated radioiodine treatment. The patient was treated for this hepatic accumulating metastasis eight times by 59.2 GBq total dose of radioiodine. Radioiodine treatments were repeated for 7 years, the patient died at the age of 92 years.
It is necessary to distinguish between diffuse and focal radioiodine accumulation in a liver. Only a focal accumulation is characteristic for functional liver metastasis in which thyroxin synthesis is preserved. The correspondence of focal accumulation of radioiodine on whole-body scintigraphy with "cold" area on liver scintigraphy is specific for diagnosis of this metastasis. At the same time, it confirms the fact that radioiodine therapy can be both promising and successful, as we can see in the case of our patient.
分化型甲状腺癌（DTC）常发生颈部淋巴结、肺和骨转移。转移至脑、肾、皮肤和肝脏等其他部位则较为罕见。DTC的肝转移发生在疾病晚期，且主要不摄取放射性碘。功能性（摄取放射性碘）转移非常罕见。
一名85岁的滤泡型DTC患者，甲状腺及颈部淋巴结转移灶切除后，经放射性碘清除甲状腺残余组织，通过静脉注射131I后的全身闪烁扫描与使用99mTc - 胶体的肝脏闪烁扫描相结合，并在注射99mTc - MDP后进行骨闪烁扫描，检测到肝脏存在功能性转移灶。起初，多次放射性碘治疗后高血清甲状腺球蛋白水平呈假阴性。该患者针对肝脏摄取性转移灶接受了8次放射性碘治疗，总剂量为59.2 GBq。放射性碘治疗持续了7年，患者于92岁时去世。
有必要区分肝脏中弥漫性和局灶性放射性碘摄取。只有局灶性摄取是功能性肝转移的特征，其中甲状腺素合成得以保留。全身闪烁扫描中放射性碘的局灶性摄取与肝脏闪烁扫描中的“冷区”相对应，是诊断这种转移的特异性表现。与此同时，正如我们在该患者病例中所见，这证实了放射性碘治疗既有前景又能取得成功这一事实。
