FRAMELESS STEREOTATIC RADIOSURGERY FOR BRAIN METASTASES USING FACE MASK IMMOBILIZATION
Ly Do, M.D.1, Morteza Dowlatshahi, M.D.1 ,Emeka Nchkwube, M.D.2, Michael Le B.S.3, Ali Shirzadi, M.D.4, Chuong Le, M.D.5, Raymond Lee,M.D.6, Tin HLa, M.D.7, Lynne Bui, M.D.8, Peggy Lu, M.D.9.
1Cancer Care Institute, 200 Jose Figueres Ave. # 199, San Jose, CA 95116, 2 E&D Nchekwube, MD, INC 1825 Civic Center Dr. # 17, Santa Clara, CA 95050, 3University of South Carolina, Columbia, SC 29208, 4South Bay Brain and Spine, 2577 Samaritan Dr. #710, San Jose, CA 95124, 5Wave Neurology, 200 Jose Figueres Ave. #475, San Jose, CA 95116, 6Regional Medical Center Medical Oncology, 200 Jose Figueres Ave. # 245, San Jose CA 95116, 7Huan & HLa Medical Corporation, 200 Jose Figueres Ave. # 430, San Jose CA 95116, 8 Global Cancer Research Institute, Inc. 2242 Camden Ave. # 203, San Jose CA 95124, 9San Jose Medical Group, 227 N Jackson Ave, San Jose CA 95116
Purpose: To evaluate our experience of frameless stereotatic radiosurgery (SRS) using face mask immobilization in patients with brain metastases.
Methods and Materials: 15 patients with brain metastases (range, 1-3), were selected to undergo SRS. Dose of SRS was 1,800 cGy – 2,500 cGy in 3 – 5 fractions. All patients underwent MRI brain prior to treatment. MRI of the brain was then fused to our CT simulation. Gross tumor volume was expanded by 3mm to create the planning tumor volume. All patients were immobilized using aquaplast face mask. Follow-up magnetic resonance imaging (MRI) occurred on average between 1- 2 months post SRS. Patients who had CNS metastases recurrences after SRS were treated with salvage whole brain radiation.
Result: From June 2012 till April 2015, 6 out 15 patients died. Two (13.3%) developed local recurrences at the treated sites, 4 (26.6%) developed new intracranial distant recurrences, and 9 (60%) were recurrence free. The actuarial survival rates of local recurrence-free were 91% for 12 months and 72% for 24 months. The actuarial survival rates of distant recurrence-free are 56% for 12 months and 42% for 24 months. The actuarial overall survival rates were 70% for 12 months and 55% for 24 months. WBRT was administered on 3 (20%) of the 15 patients.
Conclusion: Our results on the use of frameless SRS are favorable to the literature. This suggests the use of face mask immobilization would not lead to inferior outcomes in patients who require SRS for brain metastasis. This may obviate the need for the more invasive and cumbersome immobilization techniques. This would lead to increased convenience and comfort of the patient while ensuring similar efficacy and outcomes.
Figure 1. Local Recurrence Free Survival Figure 2. Distant Recurrence Free Survivial Figure 3. Overall Survival