Radioactive iodine uptake in hyperthyroid cats after administration of recombinant human thyroid stimulating hormone

Abstract

BackgroundRadioactive iodine therapy is considered the treatment of choice for hyperthyroidism in cats, but the availability of this modality is limited by costs and hospitalization requirements. Administration of recombinant human thyroid stimulating hormone (rh‐TSH) to humans with thyroid neoplasia or nodular goiter can increase thyroidal iodine uptake, thereby allowing the use of lower radioactive iodine doses for treatment. Veterinary studies of this subject are limited, and results are conflicting.ObjectiveTo investigate the effects of rh‐TSH administration on thyroidal iodine uptake in hyperthyroid cats.AnimalsTen client‐owned hyperthyroid cats.MethodsIn this prospective clinical study, cats were administered saline (placebo), 50 μg rh‐TSH (low‐dose), and 100 μg rh‐TSH (high‐dose) in randomized crossover design with treatments separated by 7‐10 days. After each treatment, thyroid scintigraphy was performed by administering 300 μCi 123I and assessing radionuclide uptake 8 and 24 hours later. Serum thyroid hormone concentrations were measured at each visit.ResultsThyroidal percent iodine uptakes (mean ± SD at 8 and 24 hours) in cats treated with placebo (25.2 ± 13.4%, 30.0 ± 12.8%), low‐dose (24.1 ± 12.5%, 29.4 ± 13.7%), and high‐dose rh‐TSH (24.2 ± 16.3%, 30.8 ± 15.3%) were not different (P = .76). Independent of rh‐TSH administration, percent iodine uptakes were positively correlated with serum thyroid hormone concentrations.Conclusions and Clinical ImportanceOne‐time administration of rh‐TSH, even at high doses, would not be expected to lower radioactive iodine doses needed for treatment of hyperthyroidism in cats. Investigations of alternate strategies to increase thyroidal uptake of radioactive iodine are warranted.

Iodine Adsorption in a Redox-Active Metal–Organic Framework: Electrical Conductivity Induced by Host−Guest Charge-Transfer

“…However, the radionuclides generated from the nuclear power plant can pose significant risks on both human health and ecosystems if emitted into the environment . Radioactive iodine (primarily comprised of 129 I and 131 I) is a key volatile waste that can be spread through air and interferes with human metabolic processes . Various techniques and materials have been applied for I 2 capture, , and porous materials, because of their high porosity and fast adsorption kinetics, are considered to be emerging sorbents for the efficient removal of I 2 .…”

The effect of per os vs subcutaneous 123iodine administration on percentage thyroidal radioactive iodine uptake in normal cats

“…These thyroid images were acquired over 10 minutes using the parameters previously described. Given that the thyroid gland is superficial relative to the cervical skin and situated directly over the gamma camera to acquire a planar ventral image, soft tissue attenuation correction was not considered necessary as determined to be appropriate in previous studies 11‐13 …”

99m-Technetium-Pertechnetat- und 99m-Technetium-Sestamibi-Szintigrafie zur Darstellung von hypofunktionellem Schilddrüsengewebe und Staging bei einem Hund mit Schilddrüsenkarzinom

“…Die Autoren diskutieren, dass möglicherweise TSH in einer höheren Dosis gegeben werden muss, was auch bei diesem Hund erfolgte (250 vs. 100 μg/Hund). Bei Katzen induzierte eine Vorbehandlung von 25 oder 100 μg/Katze rh TSH dagegen keine Steigerung der J-123 Aufnahme [34].…”