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Prevalence of thyroid dysfunction was high in elderly patients treated with amiodarone. Cases of AIT and AIH occurred in patients with and without preexisting thyroid disorders. Because of the high incidence of amiodarone-induced thyroid dysfunction, regular testing of thyroid function is mandatory during and following amiodarone treatment.

In asymptomatic subjects with SCH due to thyroid autoimmunity, coronary microvascular function is impaired and improves after supplementation with LT4. This may partially explain the increased cardiovascular risk attributed to SCH.

An increased uptake of bone-seeking radiopharmaceuticals into malignant bone lesions could further improve the diagnostic accuracy of routine bone scanning. The tracers used in clinical routine for bone scanning are methylene-diphosphonate (MDP), dicarboxypropane-diphosphonate (DPD) and ethylenediaminetetramethylene-phosphonate (EDTMP). MDP and DPD are usually labelled with 99mTc for diagnostic use, whereas EDTMP is labelled with 153Sm for therapeutic purposes. This study aimed to compare, for the first time, bone scanning with an improved preparation of 99mTc-EDTMP (by the addition of rhenium) (carrier-added) with 99mTc-DPD. Twenty malignant bone lesions were investigated in 10 patients. The ratios of bone lesion to soft tissue (BL/ST) and of bone lesion to normal bone (BL/NB) were compared 3 h after the injection of either compound. Quantitative analysis demonstrated a significant (P<0.05) difference in BL/ST ratio in favour of 99mTc-DPD. The BL/NB ratio was not significantly different. Visual image analysis resulted in a clinically comparable interpretation of imaging studies with the use of 99mTc-DPD and carrier-added 99mTc-EDTMP. These preliminary data support the concept of carrier addition to increase bone uptake by the modification of the complex structure of 99mTc-EDTMP. However, any advantage over conventional 99mTc-based tracers for bone scintigraphy in clinical use needs to be demonstrated in controlled trials.

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SummaryAim: Estimation of the radiation exposure to neighbouring patients, personnel and relatives deriving from patients undergoing 123I-MIBG scintigraphy. Methods: For scintigraphic studies, 16 patients with suspected pheocromocytoma were injected with 340 ± 30 MBq 123I-MIBG. Dose rates were measured at a distance of 0.5 m, 1 m, and 2 m after 10 min, 3 h, 21 h, 45 h, and 68 h using three calibrated portable radiation detectors. The measured values were background corrected. Results: Ten minutes after injection the dose rate was 10.5 µS/h at a distance of 0.5 m, 3.78 µS/h at 1 m, and 0.95 µS/h at 2 m. The effective half-life was estimated to 8.68 ± 0.15 h. The maximum dose in a distance of 1 m for neighbouring patients was 46 µS/h, for personnel in a ward 27 µS/h, and to relatives in a distance of 2 m 12 µS/h. Conclusion: This study demonstrates that the calculated exposure to people around patients after 123I-MIBG injection is well below the maximum permissible annual dose limit of 1 mSv for not professionally exposed persons.