Management of brain metastases

Abstract

Brain metastases occur in 20-40% of patients with cancer and their frequency has increased over time. Lung, breast and skin (melanoma) are the commonest sources of brain metastases, and in up to 15% of patients the primary site remains unknown. After the introduction of MRI, multiple lesions have outnumbered single lesions. Contrast-enhanced MRI is the gold standard for the diagnosis. There are no pathognomonic features on CT or MRI that distinguish brain metastases from primary malignant brain tumors or nonneoplastic conditions: therefore a tissue diagnosis by biopsy should be always obtained in patients with unknown primary tumor before undergoing radiotherapy and/or chemotherapy. Some factors are prognostically important: a high Performance Status, a solitary brain metastasis, an absence of systemic metastases, a controlled primary tumor and a younger age. Based on these factors, subgroups of patients with different prognosis have been identified (RPA class I, II, III). Symptomatic therapy includes corticosteroids to reduce vasogenic cerebral edema and anticonvulsants to control seizures. In patients with newly diagnosed brain metastases prophylactic anticonvulsants should not be used routinely. The combination of surgery and whole-brain radiotherapy (WBRT) is superior to WBRT alone for the treatment of single brain metastasis in patients with limited or absent systemic disease and good neurological condition. Complete surgical resection allows a relief of intracranial hypertension, seizures and focal neurological deficits. Radiosurgery, alone or in conjunction with WBRT, yields results which are comparable to those reported after surgery followed by WBRT, provided that lesion's diameter does not exceed 3-3.5 cm. Radiosurgery offers the potential of treating patients with surgically inaccessible metastases. Still controversial is the need for WBRT after surgery or radiosurgery: local control seems better with the combined approach, but overall survival does not improve. Late neurotoxicity in long surviving patients after WBRT is not negligible; to avoid this complication patients with favorable prognostic factors must be treated with conventional schedules of RT, and monitoring of cognitive functions is important. WBRT alone is the treatment of choice in patients with single brain metastasis not amenable to surgery or radiosurgery, and with an active systemic disease, and in patients with multiple brain metastases. A small subgroup of these latter may benefit from surgery. The response rate of brain metastases to chemotherapy is similar to the response rate of the primary tumor and extracranial metastases, some tumor types being more chemosensitive (small cell lung carcinoma, breast carcinoma, germ cell tumors). New radiosensitizers and cytotoxic or cytostatic agents, and innovative technique of drug delivery are being investigated.

Enhanced chemotherapy delivery by intraarterial infusion and blood‐brain barrier disruption in the treatment of cerebral metastasis

“…Typically, patients with multiple brain metastases are exposed to WBRT as a palliative measure. 1,2,6 The rationale supporting the use of this approach relies on the demonstration that it has a high potency of controlling neurological symptoms. 18 However, survival improvement is modest, ranging from 3 to 5 months.…”

Survival of Brain Metastatic Patients in Yazd, Iran

“…In adults, lung cancer, breast cancer and melanoma are the most common causes of brain metastases respectively (Nussbaum et al, 1996). In 15% of patients primary tumors remains unknown (Soffietti et al, 2002). Usually metastatic brain tumors are diagnosed using imaging studies such as CT scanning and MRI and less commonly by tissue sampling or CSF analysis.…”

Radretumab Radioimmunotherapy in Patients with Brain Metastasis: A 124I-L19SIP Dosimetric PET Study

“…However, surgical excision can only be carried out in patients with one or a few brain metastases. In patients with more than 5 cerebral lesions, the general applicability of this form of treatment is still debated (17)(18)(19)(20).…”