Gamma Knife Center - Closed is a surgery center that offers many services, including behavioral health services/ crisis line, cancer center, and cardiovascular center. Visit Gamma Knife Center - Closed located at 18350 Roscoe Blvd., Suite 100, Northridge, CA 91325. This Northridge surgery center is one of the best in California. As part of the Dignity Health network, Gamma Knife Center - Closed is dedicated to delivering high quality, compassionate care and access to Northridge and nearby communities.