Answer to Question #11441 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues — Therapeutic Nuclear Medicine

The following question was answered by an expert in the appropriate field:


Can we keep two patients in the same iodine-131 (131I) isolation room?


Yes, two patients can occupy one room as long as your radioactive materials license does not prohibit it.

To do this, the radiation safety staff needs to ensure that the dose to all occupants adjacent to all walls does not exceed the U.S. limits on dose to members of the public. The nursing staff is considered occupational workers so their dose must not exceed the facility dose limits. Some facilities have policies that address this.

Compliance with these limits usually requires leaded walls or portable lead shields placed in the room. If there are patients or employees in an adjacent area, the dose 30 centimeters (cm) from the wall of the source of radiation cannot exceed 2 milliroentgens (mR) (0.5 microcoulomb per kilogram [µC kg-1])* in any one hour or 100 millirem (mrem) (1 millisievert [mSv])* for nonoccupational worker exposures for all hospital stays for the calendar year. An occupancy factor can be applied to a supply closet or hallway. The radiation safety staff must document that all radiation limits are met in all areas adjacent to the room.

* The limits are given here in units of mR and mrem (called traditional units) because those are the units used by the U.S. Nuclear Regulatory Agency. However, the Health Physics Society has adopted the SI (International System) units and these are given in parentheses.

Marcia Hartman, MS

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 11 January 2016. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.