Chewing-gum stimulation did not reduce the absorbed dose to salivary glands during radioiodine treatment of thyroid cancer as inferred from pre-therapy I PET/CT imaging

Methods: Duplex ultrasonography was conducted in three test persons for visual comparison of the glandular blood flow with three different stimulation types (no stimulation, chewing tasteless gum base, sucking on lemon slices). Ten patients with newly diagnosed differentiated thyroid cancer received I PET/CT dosimetry after thyroidectomy and prior to radioiodine therapy. Patients underwent a series of three I PET/CT scans (4, 24, and ≥96 h after administration of 23 MBq I). They were instructed to chew gum base (tasteless) approximately 20 min after ingesting the I-containing capsule in the course of the first day. Absorbed doses per administered I activity to the salivary glands were calculated and compared with the previously published results of the lemon-juice stimulation and non-stimulation groups.