Biteblock-head immobilizer system.

Abstract

To accurately deliver high doses of radiation to the head and neck region one must be able to achieve three primary goals: reproduce the patient set-up or position, immobilize the patient, and most importantly, position the treatment field on the patient in the same exact location on a daily basis. Many patient positioning devices are available commercially but none address the concept of positioning the treatment field on the patient. The system presented in this paper accomplishes all 3 goals. Using a biteblock and a coordinate system, it has decreased the daily set-up time and improved the accuracy of the treatment field placement on the patient. Five hundred port films were reviewed retrospectively from previously treated patients who were treated without this new system (66% of those films were approved, and 34% needed some sort of adjustment). Using the new system the accuracy of 107 port films was determined (91% were approved, while only 9% needed any type of adjustment). This newly developed system provides the extra step, treatment accuracy, that no other device has done.