Factors that influence radioactive iodine use for thyroid cancer

There is variation in the use of radioactive iodine (RAI) as treatment for well-differentiated thyroid cancer. The factors involved in physician decision-making for RAI remain unknown.

We surveyed physicians involved in postsurgical management of patients with thyroid cancer from 251 hospitals. Respondents were asked to rate the factors important in influencing whether a thyroid cancer patient receives RAI. Multivariable analyses controlling for physician age, gender, specialty, case volume, and whether they personally administer RAI, were performed to determine correlates of importance placed on patients' and physicians' worry about death from cancer and differences between low- versus higher-case-volume physicians.

The survey response rate was 63% (534/853). Extent of disease, adequacy of surgical resection, patients' willingness to receive RAI, and patients' age were the factors physicians were most likely to report as quite or very important in influencing recommendations for RAI to patients with thyroid cancer. Interestingly, both physicians' and patients' worry about death from thyroid cancer were also important in determining RAI use. Physicians with less thyroid cancer cases per year were more likely than higher-volume physicians to report patients' (p<0.001) and physicians' worry about death (p=0.016) as quite or very important in decision-making. Other factors more likely to be of greater importance in determining RAI use for physicians with lower thyroid cancer patient volume versus higher include the accepted standard at the affiliated hospital (p=0.020), beliefs about RAI expressed by colleagues comanaging patients (p=0.003), and patient distance from the nearest facility administering RAI (p=0.012).

In addition to the extent of disease and adequacy of surgical resection, physicians place importance on physician and patient worry about death from thyroid cancer when deciding whether to treat a patient with RAI. The factors important to physician decision-making differ based on physician thyroid-cancer case-volume, with worry about death being more influential for low-case-volume physicians. As the mortality from thyroid cancer is low, the importance placed on death in decision making may be unwarranted.