Thyroid Dysfunction: Relation to Radiation Dose

February 9, 2017
Bobby Lazzara, MD

Researchers examined the correlation between radiation dose for head and neck cancer and subsequent thyroid dysfunction.

Radiation therapy for cancer and development of hypothyroidism: what are the predictive risks?

A study in the journal Head and Neck reviewed the records of 102 patients who received radiation therapy for head and neck cancer.

Permanent dysfunction was seen in 24.5%, with a significantly higher incidence in women. Concurrent chemotherapy increased the risk of permanent dysfunction.

There was a significant correlation between the volume of thyroid receiving greater than 50 Gy and subsequent thyroid dysfunction.

The author’s conclusions: radiotherapy-induced thyroid dysfunction is clearly dose related; the authors recommended a mean dose of less than 54.58 Gy, noting female sex and concurrent chemotherapy add to the predictive risk.