J. Rao Nibhanupudy

Guidelines for comprehensive quality assurance in brachytherapy

Brachytherapy treatment techniques can provide significant improvement in local control and overall survival, but only when quality assurance can be guaranteed. In the absence of well-trained personnel and inadequate equipment undesirable results usually follow. To establish brachytherapy quality assurance, basic requirements for three predetermined subdivisions of clinical institutions will be forwarded. These are: (1) centers having minimum requirements to provide brachytherapy, (2) intermediate centers such as regional or community hospitals, and (3) optimal centers such as university hospitals and cancer centers. A minimum center would have no board certified radiation personnel, would make use of services of a gynecologist or surgeon, be limited to afterloading or remote afterloading techniques for uterus cancer, and quality control would be guaranteed by using simple treatment protocols with fixed intrauterine applicators. Additional quality assurance such as leak testing, etc. would be provided by a parent organization (W.H.O. or Optimal Center). An intermediate center would have at least one certified radiation personnel with expansion of brachytherapy techniques to interstitial implants with several isotopes. Like the minimum center, no teaching would be provided but some quality assurance policies would be performed at the center (e.g., autoradiographs). The optimal center would have a full complement of personnel, have total brachytherapy capabilities, have teaching programs for its staff and possibly the minimum and intermediate centers and be able to provide its own quality assurance. This presentation will highlight personnel needs, equipment requirements, academic activities, clinical experience with these systems and proposed quality assurance guidelines.

Radiation from the uranium collimators of the Varian 4-MeV accelerator.

The uranium collimator of the Varian 4-MeV accelerator produces a dose rate of 100 mR/h near the collimator opening. It can be decreased to 4% by a 6-mm Lucite shield at the level of the collimator opening. A better solution is a lead glass-mylar (EM) shield which decreases the uranium radiation to less than 3% and also provides better skin sparing during treatment than the open collimator.