The article “Exposure to Technologists from Preparing and Administering Therapeutic 131I: How Frequently Should We Bioassay?” by Kopisch et al. (J Nucl Med Technol. 2011;39:60–62) contained a mathematical error that was addressed in a June 2011 Erratum. However, additional corrections in the article are required based on the mathematical error correction in the “Results” section. The corrected paragraphs appear below:
Results
From these data, one learns that an average air concentration of 2.4E–06 kBq/mL (6.4E–08 μCi/mL) of air can be expected from the handling and administration of a dose of 5.74 GBq (155 mCi) of 131I. The NRC assumption for its derived air concentration calculations is that an average worker inhales approximately 20 L of air per minute. A technologist utilizing a full 10 min of 131I handling for a procedure would inhale about 200 L of air. One could project a total ingestion for the technologist of 0.481 kBq/mL (0.013 μCi) during such a procedure.
Discussion
First paragraph: Table 2 summarizes the number of procedures and the number of participating technologists at each of the study locations. The average number of 131I procedures performed by each technologist in this study was 4. Therefore, the average 131I dose a technologist in this study received in a year was 4 × 0.481 kBq (0.013 μCi), or 19.2 kBq (0.052 μCi), well below the NRC monitoring guideline of 185 kBq (5 μCi) per year. The actual dose would probably be lower because this estimate assumes an average dose activity of 5.74 GBq (155 mCi).
Third paragraph: This small-scale study’s results indicate a typical annual intake that is well below the level that the NRC advises as a trigger level for bioassay monitoring. The study results indicate that one would have to administer close to 2220 GBq (60,000 mCi) of 131I in 1 y to reach the NRC trigger limit for bioassay.
Conclusion
First paragraph: This small study showed an average 131I inhalation intake of 0.481 kBq (0.013 μCi) during administration of 5.74 GBq (155 mCi) of 131I in capsule form. This value allows for a full 10 min to handle, assay, and administer the dose. On the basis of this small-scale study, a technologist would have to administer approximately 185 GBq (5,000 mCi) of 131I every month to trigger the NRC threshold of 10% ALI for 131I. This is the trigger level the NRC recommends for bioassay of occupational workers.
In addition, the last column in Table 1 requires corrections and should read:
