Radioiodine therapy for thyroid cancer doesn't up stroke risk

(HealthDay)—Radioiodine (I-131) therapy for thyroid cancer is not associated with increased risk of stroke, according to a study published online Aug. 16 in Head & Neck.

Chun-Yi Lin, M.D., from Show Chwan Memorial Hospital in Changhua, Taiwan, and colleagues examined the correlation between I-131 therapy for thyroid cancer and the risk of stroke among 10,104 patients aged 20 years or older newly diagnosed with thyroid cancer during 2000 to 2010. Patients were classified into two cohorts according to receipt of I-131 therapy through 1:1 propensity score matching.

The researchers found that the risk of ischemic stroke (adjusted hazard ratio, 1.05; 95 percent confidence interval, 0.82 to 1.34) or hemorrhagic stroke (adjusted hazard ratio, 1.06; 95 percent confidence interval, 0.58 to 1.93) was not significantly higher for the I-131 therapy group versus the non-I-131 therapy group, after adjustment for age, sex, and comorbidities.

"The I-131 treatment for thyroid cancer did not increase the risk of stroke during up to 10 years of follow-up," the authors write. "However, a longer follow-up period is needed to assess late adverse effects occurring after 10 years."