Resection of brain metastases previously treated with stereotactic radiosurgery

Surgical Therapies in Brain Metastasis

Brain metastases are the most common intracranial tumors in adults and source of the most common neurological complications of systemic cancer. The treatment approach to brain metastases differs essentially from treatment of systemic metastases due to the unique anatomical and physiological characteristics of the brain. Surgery and radiosurgery are important components in the complex treatment of brain metastases and can prolong survival and improve the quality of life (QOL). Aggressive intervention may be indicated for selected patients with well-controlled systemic cancer and good performance status in whom central nervous system (CNS) disease poses the greatest threat to functionality and survival. In this review the respective roles of surgery and radiosurgery, patient selection, general prognostic factors and tailoring of optimal surgical management strategies for cerebral metastases are discussed.

Outcome After Radiosurgery for Brain Metastases in Patients With Low Karnofsky Performance Scale (KPS) Scores

PURPOSE

The objective of this retrospective study was evaluation of the outcome after stereotactic radiosurgery (SRS) in patients with intracranial metastases and poor performance status.

METHODS AND MATERIALS

Forty consecutive patients with metastatic brain tumors and Karnofsky performance scale (KPS) scores < or =50 (mean, 43 +/- 8; median, 40) treated with SRS were analyzed. Poor performance status was caused by presence of intracranial metastases in 28 cases (70%) and resulted from uncontrolled extracerebral disease in 12 (30%).

RESULTS

Survival after SRS varied from 3 days to 11.5 months (mean, 3.8 +/- 2.9 months; median, 3.3 months). Survival probability constituted 0.50 +/- 0.07 at 3 months and 0.20 +/- 0.05 at 6 months posttreatment. Cause of low KPS score (p = 0.0173) and presence of distant metastases beside the brain (p = 0.0308) showed statistically significant associations with overall survival in multivariate Cox proportional hazards regression analysis. Median survival was 6.0 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were absent, 3.3 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were present, and 1.0 month if poor performance status resulted from extracerebral disease.

CONCLUSIONS

Identification of the cause of low KPS score (cerebral vs. extracerebral) in patients with metastatic brain tumor(s) may be important for prediction of the outcome after radiosurgical treatment. If poor patient performance status without surgical indications is caused by intracranial tumor(s), SRS may be a reasonable treatment option.

Results of Surgical Resection for Progression of Brain Metastases Previously Treatedby Gamma Knife Radiosurgery

OBJECTIVE

To determine treatment outcome after surgical resection for progressive brain metastases after gamma knife radiosurgery (GKR) and to explore the role of dynamic contrast agent-enhanced perfusion magnetic resonance imaging (MRI) and proton spectroscopic MRI studies (MRS/P) in predicting pathological findings.

METHODS

Between 1997 and 2002, 32 patients underwent surgical resection for suspected progression of brain metastases from a cohort of 245 patients with brain metastases treated with GKR. Postradiosurgery MRI surveillance was performed at 6 and 12 weeks, and then every 12 weeks after GKR. In some cases, additional MRI scanning with spectroscopy or perfusion (MRS/P) was used to aid differentiation of radiation change from tumor progression. The decision to perform neurosurgical resection was based on MRI or clinical evidence of lesion progression among patients with a Karnofsky performance score of 60 or more and absent or stable systemic disease.

RESULTS

Thirteen percent (32 out of 245) of patients and 6% (38 out of 611) of lesions required surgical resection after GKR. The median time from GKR to surgical resection was 8.6 months (range, 1.7-27.1 mo). The 6-, 12-, and 24-month actuarial survival from time of GKR was 97, 78, and 47% for the resected patients and 65, 40, and 19% for the nonresected patients (P < 0.0001). The two-year survival rate of patients requiring two resections after GKR was 100% compared with 39% for patients undergoing one resection (P = 0.02). The median survival of resected patients was 27.2 months (range, 7.0-72.5 mo) from the diagnosis of brain metastases, 19.9 months (range, 5.0-60.7 mo) from GKR, and 8.9 months (range, 0.2-53.1 mo) from surgical resection. Tumor was found in 90% of resected specimens and necrosis alone in 10%. MRS/P studies were performed in 15 resected patients. Overall, MRS/P predicted tumor in 11 lesions, confirmed pathologically in nine lesions, and necrosis alone was found in two. The MRS/P predicted necrosis alone in three, whereas pathology revealed viable tumor in two and necrosis in one lesion.

CONCLUSION

Surgical intervention of progressive brain metastases after GKR in selected patients leads to a meaningful improvement in survival rates. Further studies are necessary to determine the role of MRS/P in the postradiosurgery surveillance of brain metastases.

Indications for resection and radiosurgery for brain metastases

PURPOSE OF REVIEW

This review is focused on indications for resection, stereotactic radiosurgery, and fractionated radiotherapy for patients with single or multiple brain metastases. Our purpose is to summarize the indications and effect of these management approaches.

RECENT FINDINGS

Brain metastases are a frequent challenge in patients with extracranial solid cancers. More than 40% of patients with cancer will develop metastases to the brain. While some patients present with large lesions and symptoms related to mass effect, many are diagnosed when asymptomatic tumors are found on screening studies. The main options for patients with brain metastases are whole brain radiation therapy, surgical resection, and stereotactic radiosurgery. Much information regarding outcomes, survival, management morbidity, and quality of life is available. Randomized, class III clinical trials demonstrate that multimodal therapy is important for both life quality and extended survival. A better understanding of the current therapeutic options should result in improvements in patient care.

SUMMARY

This is a review of the literature from May 2004 to June 2005 with special attention on publications related to effect on quality of life with different procedures and therapies.