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Cari Kitahara Awarded Scientific Tenure by the NIH

photograph of Dr. Cari Kitahara

In March 2021, Cari Kitahara, Ph.D., was awarded scientific tenure by the NIH and promoted to senior investigator in the Radiation Epidemiology Branch (REB). Dr. Kitahara’s research focuses on two of REB’s high priority research areas: the etiology of thyroid cancer, which is one of the most radiogenic tumors, and cancer risk in patients and medical personnel exposed to radiation, particularly from diagnostic procedures. Her discoveries have impacted clinical practice and radiation protection.  

Dr. Kitahara has developed and directed large international collaborations to study environmental, lifestyle, and clinical risk factors for thyroid cancer. Her work established obesity as a modifiable factor, and she pioneered complex linkages of birth/early life medical records and cancer registry data with Scandinavian collaborators to examine the relationship of perinatal characteristics and exposures to risk of thyroid cancer in mothers and their offspring. In addition, she utilized novel descriptive epidemiological methods to evaluate incidence trends, providing the most compelling evidence to date for a true increase in thyroid cancer in the U.S., namely rising trends in incidence of advanced disease and disease-specific mortality.

In her leadership role in the U.S. Radiologic Technologists Study, the largest cohort of medical workers in the world, Dr. Kitahara has spearheaded efforts to study nuclear medicine workers. Through close collaboration with REB dosimetrists, she has demonstrated that occupational doses to medical staff who perform nuclear medicine procedures and fluoroscopy-guided procedures are several times higher than doses to those performing general radiologic procedures, and that increased doses are associated with adverse health outcomes. These findings led to efforts to reinforce and improve personal protective equipment and occupational monitoring, and informed regulatory decisions for U.S. occupational dose limits. 

In parallel to her occupational research, Dr. Kitahara investigates risks to patients from nuclear medicine procedures. She led an international effort to extend the follow-up of the largest international cohort of hyperthyroid patients and partnered with REB dosimetrists to develop the first individualized exposure assessment for the cohort. Her analysis of those data resulted in a report establishing that radioactive iodine treatment increases cancer risks in these patients. Her findings have been widely discussed by medical professional societies and clinical guidelines committees due to the potential for influencing treatment recommendations and patient preferences.