Gamma Knife Radiosurgery For Metastatic Brain Tumors From Small Cell Lung CancerAchilles Fakiris1, Jennifer Zook1, Mark Henderson11Indiana University School of Medicine, Indianapolis, USA Keywords: lung cancer, brain metastasis, gamma knife, outcome, cancer
Chemotherapy and/or whole brain radiation therapy (WBRT) have traditionally been the gold standard treatment for patients that have brain metastasis from small cell lung cancer (SCLC). Radiosurgery with or without WBRT has also been advocated in patients with lung cancer; however most patients studied had non-small cell lung cancer. Because small cell lung cancer has a different radiobiology and propensity to metastasize quickly, it is unclear if patients with small cell lung cancer achieve benefit from radiosurgery compared to those with non-small cell lung cancer.
We retrospectively reviewed institutional data on patients with SCLC who have undergone gamma knife radiosurgery (GKS) for brain metastasis.
Records were reviewed from the Department of Radiation Oncology at Indiana University; 16 patients with SCLC were treated with GKS for 43 different brain lesions. The median age was 60 years old (range, 44-67) and the median number of lesions treated per patient was 2 (range, 1-8). Fifteen of sixteen patients had previously received WBRT. Eleven of these patients had WBRT because of known brain metastasis, and 4 had received prophylactic cranial irradiation (PCI). One patient received GKS as a planned boost after WBRT.
Follow-up was unavailable for 4 patients and the remaining 12 had a mean follow-up of 6.6 months (range, 0-21.3).
Overall median survival from the time of GKS was 5.2 months (range, 2.3-22.8). The patients that had known brain metastasis at the time of WBRT and had GKS as salvage or boost had a median survival of 4.8 months (range, 2.3-22.8). The remaining 5 patients, 4 of whom previously had PCI prior to brain metastasis diagnosis, had a median survival of 14.8 months. Two of these patients are still alive at 11 and 13 months after GKS. Local recurrence occurred in 6/16 (38%) patients and 8/43 (19%) treated lesions. The median time to recurrence was 8.6 months. Three of 4 patients who had PCI prior to brain metastasis diagnosis had local recurrence compared to 1/10 of those treated for recurrent disease after WBRT.
This is a retrospective study.
In our series, patients with SCLC who were being treated for recurrent brain metastasis at the time of GKS had poorer survival compared to patients being treated for first diagnosis of brain metastasis after PCI.
The local recurrence rate was higher in the patients that had previously received PCI followed by brain metastasis diagnosis compared to the patients who were being treated for recurrent disease after WBRT. Project Roles:
A. Fakiris (), J. Zook (), M. Henderson ()