Brain metastases (BM) occur in 20-40% of cancer patients and they represent a significant cause of morbidity and mortality. Gamma Knife Radiosurgery (GKR) is a well-established treatment modality for brain metastases. Large multi centre studies have reported a consistently high local tumour control rate of around 90% following GKR and superior clinical outcomes for GKR without whole-brain radiation therapy. A retrospective study by the Queen Square Gamma Knife centre provide comparable or superior results.
QSRC has undertaken its own retrospective study, led by Mr Neil Kitchen (Clinical Lead) and Cornel Tancu (Clinical Research Fellow) assessing the overall survival and local tumour control rate in our patients treated for brain metastases (BM). The cohort (to December 2016) consisted of 108 GK procedures performed in 95 patients with a total number of 391 metastases treated in this population with a mean number of 4 BMs/patient (range 1 to 18). The main three primary origins of BMs were lung, breast carcinoma and malignant melanoma.
The median overall survival from Kaplan-Meier analysis was 14.7 months. Patient with WHO Performance Score (PS) of 0 and 1 showed prolonged median survival comparing with those with PS 2 (19.8 and 14.7 vs 5.2months). The control of the extracranial disease was also statistically correlated with prolonged survival (p<0.001).
The percentage of the BMs with complete response, reduction or stability at 2, 6 months and on their last MRI were 96.5%, 92% and 93% respectively. Gamma Knife treatment provided an excellent overall local tumour control rate of 97%. The median overall survival of 14.7 months was comparable or superior to results by others for similar series of patients. Research to evaluate GKR for patients treated for brain metastases continues as part of our research programme and is set for a further boost with the installation of a Gamma Knife ICON in coming months.