He was astonished and inspired but saw an opportunity to improve it. The Gamma Knife relied on a physical cage to coordinate the location of the subject's head and the device delivering the radiation; Adler wanted to use medical images to guide the beam, instead of the cage.
The Gamma Knife, a device that uses focused radiation to treat brain tumors, was initially guided by a physical cage to position the patient's head and deliver the treatment. Adler, inspired by its potential, sought to improve it by using medical imaging to guide the beam instead of relying on the cage.