Interdisciplinary Initiatives Program Round 1 - 2000

Daniel Kim, Neurosurgery
John Adler, Neurosurgery
Ken Salisbury, Computer Science
Martin Murphy, Radiation Oncology
Chang-ming Ma, Radiation Oncology
Bernard Widrow, Electrical Engineering

Cancer treatment is an ongoing challenge as many tumors cannot be treated optimally with current conventional methods. Radiation therapy exposes a wide area around a tumor, resulting in side effects. Stereotactic radiosurgery was developed to treat brain tumors with tremendous accuracy. This accuracy was made possible by fixing the patient’s head to a rigid frame that could be used as a reference by which to target lesions. Increased accuracy enabled increasing the radiation dose and, hence, the efficacy, while limiting injury to surrounding tissue . As the frame was both uncomfortable and limited to head application, researchers at Stanford University developed image-guided radiosurgery. In this system, lesions are referenced with respect to skeletal landmarks derived from x-rays pictures and obviates the need for a frame. This system, the CyberKnife, has been shown to deliver radiation as accurately as frame-based systems. In addition, this system uses a robotic arm that can deliver precisely shaped radiation doses by freely moving the radiation source around the patient during treatment. With no frame limitations and more degrees of spatial freedom, this system can theoretically be applied anywhere skeletal landmarks or other x-ray visible markers can be imaged. We are exploring the application of image-based radiosurgery to lesions of the spine and the feasibility of treating lung lesions. This project will combine advances in image-guided robotics and knowledge of medical radiation dosimetry to improve and extend the range of the CyberKnife to tumors in the spine and within the lung.