Emerging molecular and precision medicine makes nuclear medicine a de facto choice of imaging, especially in the era of target-oriented medical care. Nuclear medicine is minimally invasive, four-dimensional (space and time or dynamic space), and functional imaging using radioactive biochemical tracers in evaluating human diseases on an anatomically configured image. Many radiopharmaceuticals are also used in therapies. However, there have been concerns over the emission of radiation from the radionuclides, resulting in wrongly neglecting the potential benefits against little or any risks at all of imaging to the patients. The sound concepts of radiation and radiation protection are critical for promoting the optimal use of radiopharmaceuticals to patients, and alleviating concerns from caregivers, nuclear medicine staff, medical colleagues, and the public alike.

Objectives: Neuroimaging studies in the past 20 years have documented an age-related decline in striatal dopamine transporters (DATs), which is a marker of dopaminergic neurodegeneration; however, concerns about ethnic variations in the decline in DAT with age have not been addressed. The purpose of this study was to assess the rate of striatal DAT loss in healthy Taiwanese adults using kit-based ^99mTc-TRODAT-1, a radioligand for DAT SPECT. Patients and Methods: Fifty healthy subjects (mean age ± SD, 63 ± 12 years; range, 30–80 years) were studied. ^99mTc-TRODAT-1 was prepared from a lyophilized kit. Brain DAT SPECT imaging was acquired between 165 and 195 minutes postinjection (~740 MBq or 20 mCi) using a dual-head camera equipped with fan-beam collimators (Helix SPX; GE). Specific uptake in the striatum (ST), caudate nucleus (CA), and putamen (PU) were calculated from reconstructed transaxial slices at the level of maximal striatal activity. Occipital cortices were used as reference areas. Data were presented as specific binding ratios. Results: Age had a significant moderate to large negative effect on striatal DAT, which declined by −25.7% ± 6.10% between the ages of 30 and 80 years, equivalent to 6.4% loss per decade. The rates of decline in the CA and PU were 6.9% and 7.3% per decade, respectively. Conclusions: This study suggests ethnic variations may not significantly affect the age-related decline in DAT. The data generated in this study could also be used as a reference to estimate DAT loss/occupancy in patients with DAT-related diseases.

A 50-year-old woman with end-stage renal disease presented with recurrent hyperparathyroidism after parathyroidectomy. ^99mTc-MIBI scintigraphy did not show MIBI-avid lesion in the neck or mediastinum but in bilateral lung fields instead. On suspicion of malignancy, ¹⁸F-FDG PET/CT was performed and depicted no significant FDG uptake throughout the whole body. After resection of the pulmonary nodules, the final histopathology revealed benign parathyroid hyperplasia with pulmonary seeding, which is exceptionally a rare entity.

18F-fluorodeoxyglucose ([18F]-FDG) positron emission tomography/computed tomography (PET/CT) is a useful functional image technique to evaluate the disease extent in many cancers, as well as differentiate benign disease from malignant metastasis. We report the case of a 49-year-old woman with breast cancer and suspected lung metastasis by conventional images. After FDG-PET/CT demonstrating faint, or even no FDG uptake in bilateral pulmonary nodules, accompanied with obvious uterine fibroids, benign metastasizing leiomyoma (BML) of the lung was included in a differential diagnosis and finally confirmed by surgical pathology. FDG PET/CT showed its value in the diagnosis of BML in the breast cancer patient who was misleading as lung metastasis during outpatient follow-up.