[1] Univ Calif San Francisco, Dept Neurol Surg, 505 Parnassus Ave,Room M779, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Ctr Healthcare Value, San Francisco, CA 94143 USA
[3] Mem Sloan Kettering Canc Ctr, Dept Radiat Oncol, 1275 York Ave, New York, NY 10021 USA
[4] Univ Calif San Francisco, Dept Epidemiol & Stat, San Francisco, CA 94143 USA
[5] Univ Calif San Francisco, Philip R Lee Inst Hlth Policy Studies, San Francisco, CA 94143 USA