Differentiated Thyroid Cancer and Brain Metastases

Brain metastases are uncommonly detected in patients with differentiated thyroid carcinoma (DTC), often only being identified at autopsy. Screening imaging studies to detect brain metastases are unlikely to be warranted in asymptomatic patients, but those who present with suggestive neurologic symptoms should be promptly evaluated by magnetic resonance imaging. In the setting of oligometastatic disease (one to three isolated intracerebral lesions), stereotactic radiosurgery or surgical excision is an appropriate intervention, depending upon the patient’s full extent of their disease and comorbidities; whole-brain radiotherapy would be recommended in the setting of more widespread intracerebral metastases. Radioactive iodine may provide some therapeutic benefit if there is sufficient uptake and retention of 131-I, which can be suggested by pretreatment diagnostic scanning and/or dosimetry. Pharmacologic therapy with glucocorticoids can reduce complications from peritumoral edema, and TSH-suppressive thyroid hormone therapy should be maintained. Data are lacking on the efficacy of systemic therapies such as kinase inhibitors or cytotoxic chemotherapy specific to brain metastases from DTC, but given reports suggesting benefit with these agents in the treatment of other malignancies metastatic to the brain, these therapies may also be considered when appropriate.