What dietary restriction is recommended for patients before receiving I-131 therapy?

A low iodine diet is recommended for patients before receiving I-131 therapy because it helps to optimize the effectiveness of the treatment. I-131 is a radioactive isotope used primarily in the treatment of thyroid cancer and hyperthyroidism. When patients consume a low iodine diet prior to therapy, it increases the uptake of radioiodine by the thyroid gland.

This dietary restriction works on the principle that when iodine levels in the body are low, the thyroid gland will compensate by absorbing any available iodine more efficiently, including the radioactive iodine administered during the therapy. This enhanced uptake is crucial for the I-131 to effectively target and destroy thyroid tissues or cancer cells.

In contrast, consuming a high iodine diet might inhibit the uptake of I-131, as the thyroid gland would already be saturated with stable iodine, making the therapy less effective. Similarly, diets that promote high protein or carbohydrates without restrictions do not address the specific need to limit iodine intake, thus would not adequately prepare the patient for the therapy. Therefore, adhering to a low iodine diet for a week prior to I-131 therapy plays a vital role in maximizing the treatment's efficacy.