Treatment of Brain Metastases

Abstract

Brain metastases (BMs) occur in 10% to 20% of adult patients with cancer, and with increased surveillance and improved systemic control, the incidence is likely to grow. Despite multimodal treatment, prognosis remains poor. Current evidence supports use of whole-brain radiation therapy when patients present with multiple BMs. However, its associated cognitive impairment is a major deterrent in patients likely to live longer than 6 months. In patients with oligometastases (one to three metastases) and even some with multiple lesions less than 3 to 4 cm, especially if the primary tumor is considered radiotherapy resistant, stereotactic radiosurgery is recommended; if the BMs are greater than 4 cm, surgical resection with or without postoperative whole-brain radiation therapy should be considered. There is increasing evidence that systemic therapy, including targeted therapy and immunotherapy, is effective against BM and may be an early choice, especially in patients with sensitive primary tumors. In patients with progressive systemic disease, limited treatment options, and poor performance status, best supportive care may be appropriate. Regardless of treatment goals, use of corticosteroids or antiepileptic medications is helpful in symptomatic patients. In this review, we provide a summary of current therapy, as well as developments in the treatment of BM from solid tumors.

Fig 1.

Prognosis of patients with brain metastases (BM) by Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) score. Breast cancer subtypes are as follows: basal: triple negative; luminal A (LumA): estrogen receptor (ER)/progesterone receptor (PR) positive, human epidermal growth factor receptor 2 (HER2) negative; luminal B (LumB): triple positive; HER2: ER/PR negative, HER2 positive. ECM, extracranial metastases; KPS, Karnofsky performance score; n/a, not applicable; NSCLC, non–small-cell lung cancer; SCLC, small-cell lung cancer. Data adapted.

Fig 2.

T1 postcontrast axial magnetic resonance image demonstrating a new large contrast-enhancing right frontal mass in a 40-year-old woman being treated for metastatic ovarian carcinoma. She was responding well systemically to chemotherapy when she developed a left hemiparesis. This large homogeneously enhancing right frontal lesion with associated vasogenic edema and central restricted diffusion was identified. Given atypical clinical and radiologic features, biopsy was performed and revealed lymphoma. This case highlights the need to consider other diagnoses for a brain lesion in a patient with known cancer, especially when clinical and radiologic features are unusual.

Fig 3.

A 71-year-old man was found to have asymptomatic brain metastases on diagnosis of lung adenocarcinoma. (A) T1 postcontrast magnetic resonance imaging (MRI) demonstrating two brain metastases. Because of the presence of an EGFR mutation and lack of neurologic symptoms, erlotinib was initiated for treatment of his systemic and CNS disease. (B) T1 postcontrast MRI demonstrating a response after only 1 month of erlotinib.

Fig 4.

A 60-year-old man underwent surgical resection followed by stereotactic radiosurgery for an isolated left frontal metastasis secondary to lung adenocarcinoma. A year later, he developed an asymptomatic new contrast-enhancing lesion. (A) T1 postcontrast magnetic resonance imaging (MRI) demonstrating a heterogeneously contrast-enhancing left periventricular mass. (B) Dynamic contrast-enhanced perfusion MRI demonstrating lack of increased plasma volume in the contrast-enhancing left periventricular mass, strongly suggesting this is radiation necrosis. The patient was monitored with serial imaging with no significant growth of mass or new metastatic lesions.