Background: Low-intensity focused ultrasound (LIFU), a non-invasive targeted brain stimulation technology, has shown promise for therapeutic applications in Alzheimer's disease (AD) patients. Despite its potential, the implications of repeated LIFU neuromodulation in AD patients remain to be investigated. Objective: This pilot study evaluated the safety and potential to improve cognition and functional connectivity following repeated LIFU treatment in AD patients. Methods: Ten early-stage AD patients underwent six sessions of neuronavigation-guided LIFU targeting the left dorsolateral prefrontal cortex (DLPFC) within 2–3 weeks, alongside ongoing standard pharmacotherapy. Neuropsychological assessments and resting-state functional magnetic resonance imaging were performed at baseline and eight weeks post-treatment. Results: Memory performance (p = 0.02) and functional connectivity between the left DLPFC and both the left perirhinal cortex and left dorsomedial prefrontal cortex (corrected p < 0.05) significantly improved from baseline. Additionally, enhancements in memory performance were positively correlated with increases in functional connectivity of the left DLPFC with the left perirhinal cortex (Kendall's tau = 0.56, p = 0.03). No adverse events were reported during the LIFU treatments or at the subsequent follow-up. Conclusions: LIFU may have the therapeutic potential to enhance both brain network connectivity and memory functions in AD patients. Our results provide a basis for further research, including randomized sham-controlled trials and optimization of stimulation protocols, on LIFU as a supplementary or alternative treatment option for AD. Trial registration: Clinical Research Information Service, KCT0008169, Registered on 10 February 2023

Objective: To compare the prognostic values of metabolic parameters from pretreatment PET/CT between limited disease (LD) and extensive disease (ED) small cell lung cancer (SCLC) patients. Methods: Data on 118 newly diagnosed SCLC patients (50 LD and 68 ED) who underwent pretreatment positron emission tomography–computed tomography (PET/CT) were reviewed. For PET, metabolic parameters were measured for: (1) primary tumor, maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis; and (2) all tumor lesions, SUVmax of the hottest tumor, whole body metabolic tumor volume (WBMTV), and whole body total lesion glycolysis (WBTLG). Prognostic values of metabolic parameters and other clinical variables were analyzed to predict overall survival (OS). Results: In LD, SUVmax of the primary tumor was an independent prognostic factor for OS. Patients with high SUVmax showed significantly worse OS than those with low SUVmax. In ED, WBMTV and WBTLG were independent prognostic factors for OS. Patients with high WBMTV or WBTLG showed significantly worse OS than those with low WBMTV or WBTLG. Conclusions: SUVmax of primary tumor was the only independent prognostic factor for OS in LD SCLC patients. WBMTV and WBTLG were independent prognostic factors in ED SCLC patients.

Background: In preparation for ¹³¹I ablation, temporary withdrawal of thyroid hormone is commonly used in patients with thyroid cancer after total thyroidectomy. The current study aimed to investigate brain glucose metabolism and its relationships with mood or cognitive function in these patients using ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG-PET). Method: A total of 40 consecutive adult patients with thyroid carcinoma who had undergone total thyroidectomy were recruited for this cross-sectional study. At the time of assessment, 20 patients were hypothyroid after two weeks of thyroid hormone withdrawal, while 20 received thyroid hormone replacement therapy and were euthyroid. All participants underwent brain ¹⁸F-FDG-PET scans and completed mood questionnaires and cognitive tests. Multivariate spatial covariance analysis and univariate voxel-wise analysis were applied for the image data. Results: The hypothyroid patients were more anxious and depressed than the euthyroid participants. The multivariate covariance analysis showed increases in glucose metabolism primarily in the bilateral insula and surrounding areas and concomitant decreases in the parieto-occipital regions in the hypothyroid group. The level of thyrotropin was positively associated with the individual expression of the covariance pattern. The decreased ¹⁸F-FDG uptake in the right cuneus cluster from the univariate analysis was correlated with the increased thyrotropin level and greater depressive symptoms in the hypothyroid group. Conclusions: These results suggest that temporary hypothyroidism, even for a short period, may induce impairment in glucose metabolism and related affective symptoms.