Modification of a motel-type room to accommodate patients receiving radioiodine therapy: reduction of environmental exposure.

Patients receiving ¹³¹I-based therapies are generally restricted in leaving the medical institution. In the U.S., the U.S. Nuclear Regulatory Commission (U.S. NRC) has developed the rule that a ≤ 7 mR h⁻¹ reading at 1 m from the patient (or 33 mCi) is sufficient to allow unrestricted release. Because of home situations and other constraints, it is preferable that a patient-specific release level be determined by the radiation safety staff. Locally, the City of Hope has instituted a general release criterion of ≤ 2 mR h⁻¹ at 1 m. While contributing to a reduction in public exposure, this as low as reasonably achievable (ALARA) approach is difficult to justify on a cost basis due to the expense of maintaining the radioactive individual in a hospital room. Instead, it was determined that a motel-type room already on the campus be modified to allow the patient to remain on-site until at or below a locally permitted release level. By adding lead to the bathroom area and sealing the tile surfaces, the room may be converted for less than $5,000. Daily cost for the patient is $65. In comparing the use of this facility for thyroid cancer patients from 2006 to 2010, it was found that the public exposure at 1 m was reduced by approximately 70% as compared to release at the 7 mR h level. In addition, controlling the release reduces the likelihood of a radiation incident in the public environment such as on public transportation or in a hotel.