Tumor recurrence and survival following gamma knife surgery for brain metastases

Estimating the Additive Benefit of Surgical Excision to Stereotactic Radiosurgery in the Management of Metastatic Brain Disease

BACKGROUND:

There are limited data on the benefits of surgical tumor resection plus stereotactic radiosurgery (SRS) in comparison with SRS alone for patients with oligometastatic brain disease.

OBJECTIVE:

To determine the benefit of adding resection to SRS.

METHODS:

We reviewed 162 consecutive patients with oligometastatic brain disease, who underwent surgical tumor resection and SRS boost (n = 49) or SRS alone (n = 113). Patients receiving prior whole brain radiation therapy were excluded. Factors related to patient survival and time-to-local recurrence (TTLR) were determined by Cox regression. The effect of complete resection + SRS boost on survival was further explored by propensity score matching.

RESULTS:

The average age of the cohort was 65.3 years, it was 49.4% female, and included 260 brain tumors, of which 119 tumors were single. Seventy-three brain tumors recurred (28%). TTLR was related to radiation-sensitive pathology (hazards ratio [HR] = 0.34, P = .001), treatment volume (HR = 1.078/mL, P = .002), and complete tumor resection (HR = 0.37, P = .015). Factors related to survival were age (HR = 1.21/decade, P = .037), Eastern Cooperative Oncology Group performance score (HR = 1.9, P = .001), and complete surgical resection (HR = 0.55, P = .01). Propensity score matched analysis of complete surgical resection + SRS boost (n = 40) vs SRS alone (n = 80) yielded nearly identical survival results (HR = 0.52, P = .030) compared with the initial unmatched sample. Incomplete tumor resection had both median survival and TTLR equivalent to SRS alone.

CONCLUSION:

Complete surgical resection + SRS boost is associated with improved survival and reduced likelihood of local tumor recurrence in comparison with SRS alone. Incomplete resection did not improve survival or TTLR compared with SRS alone.

Treatment of central nervous system metastases: parenchymal, epidural, and leptomeningeal

PURPOSE OF REVIEW

With prolonged survival from systemic therapies in the adjuvant and salvage setting, and because these agents cannot cross the intact blood-brain barrier, central nervous system metastases are becoming a therapeutic challenge in oncology.

RECENT FINDINGS

Recent therapeutic achievements include an extended use of surgery and radiosurgery. Although each of these treatment modalities has its own indications, in patients eligible for both treatments the upfront comparison of these two techniques has not been performed yet. Systemic chemotherapies and biotherapies may be effective in the management of central nervous system metastases as they may act on both neurologic and extra-central nervous system lesions. In the treatment of epidural metastases, a surgical procedure providing immediate direct circumferential decompression of the spinal cord followed by local irradiation has been demonstrated in a prospective randomized trial. The management of leptomeningeal metastases remains controversial and of limited efficacy especially in chemoresistant tumours and still relies on the combination of chemotherapy (intrathecal and intravenous) and focal radiotherapy.

SUMMARY

Aggressive treatments in patients with early diagnosis and in whom central nervous system metastases are the life-threatening location may provide a substantial increase in survival and favourably affect quality of life.

Management of metastatic melanoma patients with brain metastases

Brain metastases seem to be an almost inevitable complication in patients with metastatic melanoma. Except for the rare patients who can undergo successful surgical resection of brain metastases, current management strategies do not appear adequate and result in a poor outcome (median survival, 2-4 months). In recent small series, stereotactic radiosurgery or gamma-knife treatment has suggested improvement in local control compared with whole brain radiation therapy. We have recently shown prolonged survival (11.1 months) using a multimodality treatment approach in 44 sequential patients with melanoma brain metastases. A subsequent study demonstrated that the outcome of biochemotherapy for metastatic melanoma is not affected by the presence or absence of brain metastases. Our results suggest that the outcome of patients with melanoma brain metastases can be improved using a multidisciplinary management strategy.