(1) Background: This study aimed to investigate the association between radioactive iodine (RAI) and long-term cardiovascular disease (CVD) morbidity/mortality in thyroid cancer. (2) Methods: The study was conducted using data from the Taiwan National Health Insurance Database during 2000–2015. Thyroid cancer patients aged ≥20 years were categorized into RAI (thyroidectomy with RAI) and non-RAI (thyroidectomy only) groups. The Cox proportional hazard regression model and Kaplan–Meier method were used for analysis. (3) Results: A total of 13,310 patients were included. Kaplan–Meier analysis demonstrated that the two groups had similar cumulative risks of CVD (log-rank p = 0.72) and CVD-specific mortality (log-rank p = 0.62). On Cox regression analysis of different RAI doses, the risk of CVD was higher in the cumulative dosage >3.7 GBq (hazard ratio = 1.69, 95% confidence interval = 1.24–2.40, p < 0.001). (4) Conclusions: RAI was not associated with an increased risk of CVD in thyroid cancer. However, CVD surveillance is indicated in the patients receiving the cumulative RAI dosage above 3.7 GBq.

Background/Objectives: Subjective cognitive decline (SCD) may serve as an early indicator of Alzheimer’s disease (AD). This study investigates regional cerebral blood flow (rCBF) alterations in individuals with SCD using single photon emission computed tomography (SPECT). To characterize rCBF patterns in SCD patients compared to healthy controls and examine the relationship between rCBF and cognitive function. Methods: We compared rCBF in 20 SCD patients and 20 age- and sex-matched healthy controls using 99mTc-ECD SPECT imaging. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Geriatric Depression Scale (GDS), and Cognitive Abilities Screening Instrument (CASI). Results: SCD patients demonstrated significantly reduced rCBF in the right superior temporal gyrus (rSTG) (mean uptake ratio [UR] = 0.864 ± 0.090 vs. 1.030 ± 0.074, p < 0.001) and right caudate (mean UR = 0.783 ± 0.068 vs. 0.947 ± 0.062, p < 0.001) compared to controls. Additionally, negative correlations were observed between rCBF in these regions and CDR scores, particularly in the memory domain (rSTG: r = −0.37, p = 0.016; right caudate: r = −0.39, p = 0.011). Conclusions: Reduced rCBF in the rSTG and right caudate may represent early biomarkers for SCD, which could aid in the early detection of AD. These findings suggest that SPECT imaging might be a valuable tool for identifying individuals at risk of cognitive decline, potentially allowing for earlier intervention and targeted preventive strategies in the management of AD.

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.