Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)

TREATMENT FOR PATIENTS WITH A SINGLE METASTASIS:

About 10% to 20% of patients with cancer will have a single brain metastasis. The extent of extracranial disease can influence subsequent treatment of the brain lesions. In the presence of extensive systemic disease, surgery provides little benefit for overall survival (OS). In patients with minimal extracranial disease, combined modality treatment should be used. Treatment is usually surgical resection followed by radiation therapy. In a randomized trial, this approach showed that patients who received whole-brain radiation therapy (WBRT) after resection were much less likely to fail in the brain and were significantly less likely to die of neurological causes, but OS was the same.[1] A Radiation Therapy Oncology Group (RTOG) study randomized patients with one to three metastases with a maximum diameter of 4 cm to WBRT with or without a stereotactic boost. The combined-treatment group had a survival advantage of 2 1/2 months in patients with a single metastasis but not in patients with multiple lesions. Local control was significantly better in all groups with combined therapy.[2][Level of evidence: 1iiDi]

TREATMENT FOR PATIENTS WITH MULTIPLE METASTASES:

Patients with multiple brain metastases are treated with WBRT. Surgery is reserved only for large symptomatic lesions or for obtaining tissue with an unknown primary. Stereotactic radiation surgery in combination with WBRT has been assessed and has been shown to give good local control, but median survival was not affected. Survival was determined by the extent of extracranial disease.[3] Stereotactic radiosurgery as a sole modality has been used; however, no randomized studies comparing that modality with a combined modality treatment have been done to evaluate the effect on survival.[4] An RTOG study randomized patients with one to three metastases with a maximum diameter of 4 cm to WBRT with or without a stereotactic boost. The combined-treatment group had a survival advantage of 2 1/2 months in patients with a single metastasis but not in patients with multiple lesions. Local control was significantly better in all groups with combined therapy.[2][Level of evidence: 1iiDi]

(Refer to the PDQ summaries on Breast Cancer Treatment; Colon Cancer Treatment; Non-Small Cell Lung Cancer Treatment; Small Cell Lung Cancer Treatment; and Testicular Cancer Treatment for more information.)

References:

1. Patchell RA, Tibbs PA, Regine WF, et al.: Postoperative radiotherapy in the treatment of single metastases to the brain: a randomized trial. JAMA 280 (17): 1485-9, 1998.
2. Andrews DW, Scott CB, Sperduto PW, et al.: Whole brain radiation therapy with or without stereotactic radiosurgery boost for patients with one to three brain metastases: phase III results of the RTOG 9508 randomised trial. Lancet 363 (9422): 1665-72, 2004.
3. Kondziolka D, Patel A, Lunsford LD, et al.: Stereotactic radiosurgery plus whole brain radiotherapy versus radiotherapy alone for patients with multiple brain metastases. Int J Radiat Oncol Biol Phys 45 (2): 427-34, 1999.
4. Muacevic A, Kreth FW, Tonn JC, et al.: Stereotactic radiosurgery for multiple brain metastases from breast carcinoma. Cancer 100 (8): 1705-11, 2004.