Radiation exposure to family and household members after prostate brachytherapy

Abstract

Purpose Patients with localized prostate cancer frequently seek alternatives to radical surgery and external beam radiation therapy. Permanent prostate brachytherapy is an acceptable option. However, fears of radiation exposure to family members may deter some individuals from choosing this treatment option. A direct measurement was performed to determine the expected lifetime exposure from the patient with a brachytherapy prostate implant to family members and the household. Methods and materials After a permanent brachytherapy implant with 125I or 103Pd, patients and their family members were provided radiation monitors to measure direct radiation exposure at home. Each patient was given two monitors to wear, and each member of the household, including the spouse, children, and pets, was given a single monitor. In addition, four rooms in the house frequently occupied by the patient were monitored. Based on the reading from the dosimeters measured at the first follow-up visit, the lifetime exposure to each individual or room was calculated. Forty-four patients, along with their families, agreed to participate and complied with the use of the dosimeters. Twenty-nine patients received a 125I implant and 15 a 103Pd implant. Assays were obtained on 272 monitors: 78 worn by patients, 52 worn by household members, and 142 posted in rooms. Results Exposures measured by patient dosimeters were within the expected range for the type of implant received. Exposures to family members were low. Based on dosimeter readings, the calculated mean lifetime dose to a spouse from her husband was 0.1 (range: 0.04–0.55) mSv for a 125I implant and 0.02 (range: 0.015–0.074) mSv for a 103Pd implant. Other family or household members had 0.07 (range: 0.04–0.32) mSv or 0.02 (range: 0.015–0.044) mSv for 125I and 103Pd implants, respectively. The calculated lifetime exposure did not exceed the annual limit set by the U.S. Nuclear Regulatory Commission in any of the cases. The majority of room dosimeters (94%) had no detectable radiation exposure. Conclusions Radiation exposure to family members from a patient receiving a permanent prostate brachytherapy implant with radioactive 125I or 103Pd is very low and well below the limits recommended by the U.S. Nuclear Regulatory Commission. Radiation exposure to members of a patient’s family or to the public should not be a deterrent to undergoing this procedure.