(HealthDay News) – For patients with thyroid cancer who undergo complete surgical resection, low-dose radioiodine plus thyrotropin is as effective as high-dose radioiodine, according to two studies published in the May 3 issue of the New England Journal of Medicine.
Martin Schlumberger, MD, from the Institut Gustave Roussy and University Paris-Sud, and colleagues compared two thyrotropin stimulation methods, thyroid hormone withdrawal and use of recombinant human thyrotropin, and two radioiodine doses (1.1GBq and 3.7GBq) for treatment of low-risk thyroid cancer in 684 patients who had undergone complete surgical resection. The researchers found that ultrasonography of the neck was normal in 95% of patients. Thyroid ablation was complete in 92% of patients, and the ablation rate was comparable between the radioiodine doses and thyrotropin-stimulation methods.
Ujjal Mallick, MD, from Freeman Hospital in Newcastle upon Tyne, UK, and colleagues compared low- and high-dose radioiodine (1.1GBq and 3.7GBq, respectively) in combination with thyrotropin alfa or thyroid hormone withdrawal before ablation in 438 patients with T1 to T3 thyroid tumors with possible spread to nearby lymph nodes but no metastasis. Upon analyzing the data for 421 patients, the researchers found that low-dose radioiodine was as effective as high-dose radioiodine (ablation success rates of 85% vs. 88.9%, respectively). Similar results were seen for low-dose radioiodine plus thyrotropin alfa and for high-dose radioiodine with either thyroid hormone withdrawal or thyrotropin alfa (84.3% vs. 87.6% and 90.2%, respectively).
“Low-dose radioiodine plus thyrotropin alfa is an effective and convenient treatment with reduced radiation exposure,” Mallick and colleagues write.
Two of the authors from the Schlumberger study disclosed financial ties to Genzyme.