Background Biological specimens from patients who have received radiopharmaceuticals are often collected for diagnostic testing and sent to clinical laboratories. Residual radiation has long been assumed to be minimal. However, literature is sparse and may not represent the specimen volumes or spectrum of radionuclides currently seen at National Cancer Institute (NCI)–designated cancer centers. This study examined the radiopharmaceuticals associated with patient specimens received in the hospital core laboratory and assessed the potential risk of external radiation exposure to laboratory personnel. Methods The types and amounts of radiopharmaceuticals administered in a large metropolitan hospital system were retrospectively examined over a 20-month study period. The associated biological specimens sent to the largest core laboratory in the system for testing were evaluated. In addition, manual survey meter assessment of random clinical specimens and weekly wipe tests were performed for 44 weeks, and wearable and environmental dosimeters were placed for 6 months. Results Over 11 000 specimens, collected within 5 physical half-lives of radiopharmaceutical administration, were processed by our laboratory. Manual survey meter assessment of random clinical specimens routinely identified radioactive specimens. If held in a closed palm for >2 min, many samples could potentially deliver a 0.02 mSv effective dose of radiation. Conclusions The laboratory regularly receives radioactive patient specimens without radioactive labels. Although the vast majority of these are blood specimens associated with low-dose diagnostic radiopharmaceuticals, some samples may be capable of delivering a significant amount of radiation. Recommendations for laboratories associated with NCI cancer centers are given.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.