Radiation safety parameters following prostate brachytherapy

Purpose: To determine the degree and variability of radiation exposure to t he general public from patients after I-125 or Pd-103 prostate brachytherap y, Methods and Materials: Radiation exposure measurements were made from 38 co nsecutive, unselected patients with stage T1 or T2 prostatic carcinoma who had transperineal I-125 or Pd-103 implants at the University of Washington in 1998, Results: The exposure rate at the anterior skin surface following a I-125 i mplant ranged from 2.2 to 8.9 mrem/hour (average: 5.0), The exposure rate a t the anterior skin surface from a Pd-103 implant ranged from 0.5 to 4.9 mr em/hour (average: 1.7). Based on the current Nuclear Regulatory Commission (NRC) regulations the time required to reach the annual limit at the anteri or skin surface would be 20 hours for I-125 and 59 hours for Pd-103, For ex posure at the lateral skin surface, the times would exceed 500 hours for ei ther isotope. Conclusions: This data suggest that patients need not be concerned about be ing a radiation risk to the general public following their procedure. (C) 1 999 Elsevier Science Inc.