Cohort profile – MSK radiation workers: a feasibility study to establish a deceased worker sub-cohort as part of a multicenter medical radiation worker component in the million person study of low-dose radiation health effects

Abstract

Background

The National Council on Radiation Protection and Measurements (NCRP) is coordinating an expansive epidemiologic effort entitled the Million Person Study of Low-Dose Radiation Health Effects (MPS). Medical workers constitute the largest occupational radiation-exposed group whose doses are typically received gradually over time.

Methods

A unique opportunity exists to establish an Institutional Review Board/Privacy Board (IRB/PB) approved, retrospective feasibility sub-cohort of diseased Memorial Sloan Kettering Cancer Center (MSK) medical radiation workers to reconstruct occupational/work history, estimate organ-specific radiation absorbed doses, and review existing publicly available records for mortality from cancer (including leukemia) and other diseases. Special emphasis will be placed on dose reconstruction approaches as a means to provide valid organ dose estimates that are as accurate and precise as possible based on the available data, and to allow proper evaluation of accompanying uncertainties. Such a study that includes validated dose measurements and information on radiation exposure conditions would significantly reduce dose uncertainties and provided greatly improved information on chronic low-dose risks.

Results

The feasibility sub-cohort will include deceased radiation workers from MSK who worked during the nearly seventy-year timeframe from 1946 through 2010 and were provided individual personal radiation dosimetry monitors. A feasibility assessment focused on obtaining records for about 25–30,000 workers, with over 124,000 annual doses, including personnel/work histories, specific dosimetry data, and appropriate information for epidemiologic mortality tracing will be conducted. MSK radiation dosimetry measurements have followed stringent protocols complying with strict worker protection standards in order to provide accurate dose information for radiation workers that include detailed records of work practices (including specific task exposure conditions, radiation type, energy, geometry, personal protective equipment usage, badge position, and missed doses), as well as recorded measurements. These dose measurements have been ascertained through a variety of techniques that have evolved over the years, from film badges to thermoluminescent dosimetry technology to optically stimulated luminescent methodologies. It is expected that individual total doses for the sub-cohort will have a broad range from <10 mSv to > =1000 mSv.

Conclusions

MSK has pioneered the use of novel radiation diagnostic and therapeutic approaches over time (including initial work with x-rays, radium, and radon), with workplace safety in mind, resulting in a variety of radiation worker exposure scenarios. The results of this feasibility sub-cohort of deceased radiation workers, and associated lessons learned may potentially be applied to an expanded multicenter study of about 170,000 medical radiation worker component of the MPS.

Keywords:

• Radiation
• dosimetry
• radiation protection
• epidemiology

Acknowledgements

We acknowledge the assistance of the MSK Department of Epidemiology& Biostatistics, the Department of Medical Physics, Leslie Ballantyne of Human Resources, William Morgan and Margaret Eliasinski of Information Systems, and Sharon Bayuga-Miller of Epidemiology & Biostatistics. In addition, we appreciate the support of MSK leadership (Roy Cambria, Dr. Roger Wilson, and Dr. Craig Thompson), IRB/PB reviewers, legal staff (Joanna Halperin, Kristen Ahearn, Kristen Kim, Lee Stetson, and Arielle Cireseanu), and Information Systems (William Pustorino). Special thanks to those health physicists who were responsible for maintaining the personal monitoring programs during the nearly seven decades of information covered by this feasibility study.

Disclosure statement

The authors declare no personal conflicts of interest. The views expressed in this paper represent the collective opinions of the authors and are not necessarily those of their professional affiliations.

Notes on contributors

Lawrence T. Dauer, Ph.D, is Associate Attending Physicist specializing in radiation protection at Memorial Sloan Kettering Cancer Center in the Departments of Medical Physics and Radiology. He is a Council and Board member of the NCRP and served as a member of the ICRP Committee 3, Protection in Medicine.

Meghan Woods, is a Research Project Manager at Memorial Sloan Kettering Cancer Center in the Department of Epidemiology & Biostatistics. She currently manages data collection for two multi-center studies: the Women’s Environmental, Cancer, and Radiation Epidemiology Study; and the MRI Background Parenchymal Enhancement as a Risk Factor for Breast Cancer: the IMAGINg and Epidemiology Study.

Daniel Miodownik, is a Physicist at Memorial Sloan Kettering Cancer Center in the Department of Medical Physics. He currently manages the dosimetry database for the Center and ongoing assessments of worker exposure scenarios.

Brian Serencsits, is a Physicist at Memorial Sloan Kettering Cancer Center in the Department of Medical Physics. He currently supports the medical health physics aspects of laboratory and clinical uses of radiation and radioactive material for the Center as well as ongoing training programs.

Brian Quinn, is a Technical Lead Physicist at Memorial Sloan Kettering Cancer Center in the Department of Medical Physics. He continues to research both patient and occupational dosimetry issues, concentrating on more accurately estimating organ doses.

Michael Bellamy, Ph.D, is a Staff Scientist at the Oak Ridge National Laboratory (ORNL). His research is currently concentrated on the development of accurate dosimetric assessments of organ and effective dose for both occupational and clinically exposed populations, as well as understanding fundamental micro and macro effects of radiation on the body.

R. Craig Yoder, Ph.D, directed Landauer’s technical activities relating to radiation dosimetry, particularly for applications in radiation protection for over 30 years. An internationally known expert in radiation monitoring, he led the development of optically stimulated luminescence. He is a member of NCRP and former President of the Council on Ionizing Radiation Measurements and Standards.

Xiaolin Liang, is a Senior Program Analyst at Memorial Sloan Kettering Cancer Center in the Department of Epidemiology & Biostatistics. Her primary collaboration is the Women’s Environmental, Cancer, and Radiation Epidemiology Study group and has served as an informatics specialist at the coordinating center of the study since its inception.

John D. Boice, Jr., Sc.D, is a radioepidemiologist with over 40 years of experience. He served as the President of the National Council on Radiation Protection and Measurements and is a Professor of Medicine at Vanderbilt University. Dr. Boice is the creator and leader of the Million Person Study in the United States.

Jonine Bernstein, Ph.D, is an Attending Epidemiologist at Memorial Sloan Kettering Cancer Center in the Department of Epidemiology & Biostatistics. She is a Council and Board member of the NCRP and the Principle Investigator of the NCI-funded international 24-center Women’s Environmental, Cancer, and Radiation Epidemiology Study.

Additional information

Funding

This research was funded in part by a grant from the National Institutes of Health (Support Grant No. P30 CA008748).