Early Gamma Knife stereotactic radiosurgery to the tumor bed of resected brain metastasis for improved local control

Abstract

B rain metastases are a significant source of illness and death among cancer patients 8 and will eventually develop in about 20%-40% of patients with a primary extracranial neoplasm. 9 The intent of current optimal case management remains mostly palliative. Resection has been shown to improve neurological symptoms, improve functional independence, and increase survival times. 19 However, surgery alone is associated with a 46%-59% rate of local recurrence, presumably because Early Gamma Knife stereotactic radiosurgery to the tumor bed of resected brain metastasis for improved local control Object. Optimal case management after surgical removal of brain metastasis remains controversial. Although postoperative whole-brain radiation therapy (WBRT) has been shown to prevent local recurrence and decrease deaths, this modality can substantially decrease neurocognitive function and quality of life. Stereotactic radiosurgery (SRS) can theoretically achieve the same level of local control with fewer side effects, although studies conclusively demonstrating such outcomes are lacking. To assess the effectiveness and safety profile of tumor bed SRS after resection of brain metastasis, the authors performed a retrospective analysis of 110 patients who had received such treatment at the Centre Hospitalier Universitaire de Sherbrooke. They designed the study to identify risk factors for local recurrence and placed special emphasis on factors that could potentially be addressed.Methods. Patients who had received treatment from 2004 through 2013 were included if they had undergone surgical removal of 1 or more brain metastases and if the tumor bed was treated by SRS regardless of the extent of resection or prior WBRT. All cases were retrospectively analyzed for patient and tumor-specific factors, treatment protocol, adverse outcomes, cavity outcomes, and survival for as long as follow-up was available. Univariate and multivariate Cox regression analyses were performed to identify risk factors for local recurrence and predictors of increased survival times.Results. Median patient age at first SRS treatment was 58 years (range 37-84 years). The most frequently diagnosed primary tumor was non-small cell lung cancer. The rate of gross-total resection was 81%. The median Karnofsky Performance Scale score was 90%. Tumor bed SRS was performed at a median of 3 weeks after surgery. Median follow-up and survival times were 10 and 11 months, respectively. Actuarial local control of the cavity at 12 months was 73%; median time to recurrence was 6 months. According to multivariate analysis, risk factors for recurrence were a longer surgery-to-SRS delay (HR 1.625, p = 0.003) and a lower maximum radiation dose delivered to the cavity (HR 0.817, p = 0.006). Factors not associated with increased recurrence were subtotal or piecemeal resections, prior WBRT, histology of the primary tumor, and larger cavity volume. No factors predictive of survival were identified. Symptomatic radiation-induced enhancement occurred in 6% of patients and leptomeninge...

Effectiveness of Postoperative Gamma Knife Radiosurgery to the Tumor Bed After Resection of Brain Metastases

“…There are numerous reports that postoperative GKS to the tumor bed is effective for brain metastases (10,11,13,14). One previous study reported that GKS to the tumor bed after resection was safe and effective as adjuvant treatment of brain metastases, particularly when the metastatic lesions were totally removed as in our cases (6).…”

Radiosurgery to the Postoperative Tumor Bed for Metastatic Carcinoma Versus Whole Brain Radiation After Surgery

“…However, WBRT has become increasingly implicated with global cognitive impairment that persists after cessation of treatment [3-4], thereby expanding concerns regarding quality of life despite reducing tumor burden. Furthermore, WBRT may not increase overall survival time [5-6]. Consequently, shifts in the treatment paradigm for brain metastases from postoperative WBRT to postoperative stereotactic radiosurgery (SRS) to the tumor bed are occurring [7].…”

Adaptive hypofractionated gamma knife radiosurgery in the acute management of large thymic carcinoma brain metastases

“…[141719] For these tumors, other radiation treatment modalities such as whole brain radiation therapy (WBRT) and local hypofractionated regimens are often considered. Because of the risk for long-term cognitive impairment,[1113232429] WBRT is increasingly avoided as an upfront treatment. LINAC and Gamma Knife based hypofractionated regimens have proven effective in the treatment of metastatic lesions,[81215172127282937] particularly for larger ones.…”