Innovative alpha-ray treatment of iodine-refractory thyroid cancer with multiple metastases

The radioactive iodine that emits beta rays has been used for many years for the treatment of thyroid cancer. Generally, 5-year survival rates can exceed 90%. However, some thyroid tumors become resistant to iodine treatment ("refractory to iodine") and a revolutionary approach is needed. Many research groups have attempted to define new methods of treating iodine-refractory thyroid cancer; none has shown convincing results, until now.

A research team led by Jun Hatazawa has studied targeted alpha-therapy, which has superior therapeutic effects while limiting damage to surrounding normal cells. In a new study published in the Journal of Nuclear Medicine, researchers used a large accelerator at the Nuclear Physics Research Center and facilities at the Institute for Radiation Science to successfully produce a therapeutic drug, sodium injection astatide, which emits highly therapeutic alpha rays from At-211 ions.

"When we administered therapeutic sodium, sodium astatide, to mice that had received thyroid cancer cell transplants, we found a marked regression effect of the tumor due to exposure to alpha rays, "says Tadashi Watabe, corresponding author of the study. "In particular, mice given higher doses of sodium astatide survived nearly three times longer than untreated mice, and their tumors were several times smaller."

In the study, mice with thyroid cancer cells presented with transient weight loss when they received higher doses of sodium astatide. Notably, mice given lower doses of sodium astatide showed considerable tumor suppression without weight loss, indicating that fractional alpha-ray exposure may allow effective treatment without serious side effects. . The next step is to prepare a clinical trial on treatment with sodium astatide for alpha therapy of refractory thyroid cancer with iodine with multiple metastases.

Astatide sodium radiotherapy provides alpha systemic exposure that should be an innovative treatment for a variety of cancers with multiple metastases, including refractory thyroid cancer. More importantly, injection of the therapeutic drug based on sodium astatide can allow a revolutionary therapeutic treatment of cancerous lesions in the body without external radiotherapy.