ARRT Nuclear Medicine Practice Test 2026 – Complete Prep Guide

Supersaturated potassium iodine (SSKI) solution is used in nuclear medicine primarily to block the uptake of radioactive iodine by the thyroid gland, especially in the context of treatments involving iodine-131 (I-131). When administered with I-131 tositumomab, it serves to protect healthy thyroid tissue from potential radiation damage by saturating the thyroid gland's uptake pathways, allowing therapeutic doses of I-131 tositumomab to target neoplastic tissues more effectively.

I-131 tositumomab is a radiopharmaceutical that combines monoclonal antibody therapy with radioactive iodine, which is especially useful for treating certain types of thyroid cancer and other conditions involving excessive iodine uptake. The use of SSKI in this context enhances the safety and efficacy of the treatment.

The other options do not utilize SSKI in the same manner. I-133 is not typically associated with the same protective measures, while technetium-99m-labeled red blood cells and F-18 FDG do not interact with the thyroid in the same way, as they are used for different imaging and therapeutic purposes that do not require the thyroid blocking that SSKI provides.