Management of Solitary Intracranial Metastases of Differentiated Thyroid Carcinoma: 11 Pathologically Confirmed Cases and Systematic Literature Review.

BACKGROUND: Solitary intracranial metastases of differentiated thyroid carcinoma (DTC) are rare, and their management is still controversial. This research aimed to seek suitable therapeutic methods for this disease.

METHODS: We retrospectively studied 11 pathologically confirmed cases of solitary intracranial metastases of DTC in a single institution from January 2000 to December 2016 and systematically reviewed 52 cases of this disease out of 416 cases described in the literature on PubMed. These 63 cases were analyzed by Kaplan-Meier analysis, Cox regression analysis, and post-hoc test.

RESULTS: The diameters of intracranial metastases in all 63 cases were greater than 2 cm. Lung metastases (P = 0.000) and neurosurgery (P = 0.014) were 2 independent prognostic factors of this disease. Only neurosurgery (P = 0.05) was an independent prognostic factor in the patients with lung metastases, and neurosurgery (P = 0.044) and whole brain radiotherapy (WBRT) (P = 0.041) were 2 independent factors in the patients without lung metastases. Longer overall survival (OS) was achieved in the gross total removal (GTR) and subtotal removal (STR) groups than in the no neurosurgery group (P = 0.015, P = 0.084, respectively), and there was no significance between the GTR and STR groups (P = 0.918).

CONCLUSION: The patients without lung metastases had a better prognosis than did the patients with lung metastases. Neurosurgery could obviously improve the prognosis, and if possible, GTR of metastases was supposed to be achieved; STR could be considered. WBRT was a suitable method after neurosurgery in the patients without lung metastases but could not prolong OS in the patients with lung metastases.