title: Clinical characteristics and follow-up of intracranial metastases from thyroid cancer.
abstract: BACKGROUND
  Intracranial metastasis from thyroid cancer is extremely rare. However, less is known about the risk factors for intracranial metastasis and its treatment from few retrospective studies. The aim of this study was to contribute to the understanding of this disease by analyzing patients with intracranial metastases from thyroid cancer.
  
  
  METHODS
  Between 2001 and 2014, the database of the National Cancer Center of Korea was searched for thyroid cancer patients. The clinical characteristics and site of distant metastasis according to the histological type were evaluated in the thyroid cancer cohort. Among the patients with intracranial metastases, the characteristics, histological type of primary cancer and metastatic brain tumor, additional synchronous or previous distant metastasis, treatment modalities, locations and characteristics on radiologic findings, time interval between the first diagnosis of the primary thyroid cancer and brain metastasis, thyroglobulin level at the first detection of intracranial metastasis and survival were reviewed.
  
  
  RESULTS
  A total of 10 (0.032 %) out of 3,090 thyroid cancer patients in the National Cancer Center database were identified as having intracranial metastases. The histological types of the primary thyroid cancers were papillary for six patients, follicular for three, and poorly differentiated carcinoma for one. Six of these ten patients underwent surgical resection for intracranial lesions. Whole-brain radiotherapy or tyrosine kinase inhibitors were applied to the patients as postoperative adjuvant treatment, and stereotactic radiosurgery was considered for recurrent or surgically inoperable lesions. The overall median survival time was 33 months (range, 0.5-78 months) after diagnosis of intracranial metastasis.
  
  
  CONCLUSIONS
  Surgical resection and adjuvant treatments in the contemporary era seem to result in improved survival after intracranial metastases compared with what has been reported in past studies. Considering the grave course of intracranial metastasis, the early detection and aggressive treatment of patients with a good performance status are crucial.
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Heui Seung
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Neuro-Oncology Clinic, National Cancer Center, Madu 1-dong, Ilsandong-gu, Goyang, 410-769, Korea. heonyoo@ncc.re.kr.
authors.forename: Heon
authors.initials: H
authors.lastname: Yoo
authors.affiliation: Neuro-Oncology Clinic, National Cancer Center, Madu 1-dong, Ilsandong-gu, Goyang, 410-769, Korea.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Neuro-Oncology Clinic, National Cancer Center, Madu 1-dong, Ilsandong-gu, Goyang, 410-769, Korea.
authors.forename: Ho Shin
authors.initials: HS
authors.lastname: Gwak
authors.affiliation: Neuro-Oncology Clinic, National Cancer Center, Madu 1-dong, Ilsandong-gu, Goyang, 410-769, Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Shin
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D056910:Republic of Korea; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery
keywords: Anaplastic; Brain; Follicular; Metastasis; Papillary; Skull; Thyroid cancer