National Council On Radiation Protection Research Articles

Fortification of existing rooms used for brachytherapy patients.

Often, the radiation exposure levels around brachytherapy patient rooms exceed the limits allowed by Nuclear Regulatory Commission (NRC) regulations and National Council on Radiation Protection (NCRP) recommendations. Since a neighboring patient may be present in the radiation field from a brachytherapy patient, or patients, continuously for 7 days, the dose equivalent rate must not exceed 6 muSv/hr (0.6 mrem/hr). Several boundary conditions constrain solutions to the problem of excessive radiation levels: (1) the cost should not be recurring, (2) the rooms used for brachytherapy patients must be compatible with use for nonbrachytherapy patients, (3) free access through halls must be maintained, (4) all brachytherapy rooms must be compatible with independent use, (5) shielding must not eliminate space required for a resuscitation cart, (6) shielding should not require storage, (7) the weight of shielding must remain within the tolerance of the floor, and (8) the location of beds must match utility outlets in the wall. Possible solutions to the problem include leaving rooms empty around the patient, use of portable shields, or the addition of substantial amounts of shielding material in the walls of the brachytherapy rooms, as well as changing the radionuclides routinely used. The optimum solution for a given institution depends on the frequency of brachytherapy procedures, bed occupancy rate, and available empty space.