Summary: Objective: We assessed the associations between FDG uptake in primary papillary thyroid carcinomas (PTCs) and clinicopathological features, including the BRAF V600E mutation, using quantitative and qualitative analyses of preoperative PET/CT data.Design and Patients: This was a retrospective review of 106 patients with PTC who underwent PET/CT scans between February 2009 and January 2011 before undergoing total thyroidectomy. Data collected from surgical specimens were compared with FDG uptake in the primary tumour using quantitative and qualitative analyses of preoperative PET/CT data. Clinicopathological data included the primary tumour size, subtype, capsular invasion, extrathyroid extension, multifocality, BRAF V600E mutation status, lymph node metastasis and distant metastasis.Results: The SUVmax of the primary tumour was significantly higher in patients with a primary tumour >1 cm, extrathyroid extension or the BRAF V600E mutation than in patients without these features (P<.001, .049 and <.001). Univariate analyses showed that primary tumour size, extrathyroid extension and BRAF V600E mutation status were associated with the SUVmax of the PTC. Multivariate analysis indicated that primary tumour size and the BRAF V600E mutation were associated with the SUVmax of the PTC. In a visual assessment, the primary tumour size was larger in FDG‐avid than in non‐FDG‐avid PTCs (P<.001). There was no significant difference in the presence of multifocality, thyroid capsular invasion, extrathyroid extension, BRAF V600E mutation, lymph node metastasis or distant metastasis between FDG‐avid and non‐FDG‐avid PTCs.Conclusions: Primary tumour size and the BRAF V600E mutation are significant factors associated with the SUVmax on preoperative PET/CT in patients with PTC.

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

We investigated the prognostic role of metabolic parameters from preoperative ¹⁸F-FDG PET/CT in stage II/III colorectal adenocarcinoma. A total of 327 stage II/III colorectal adenocarcinoma patients who underwent curative resection were included. The maximal standard uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were analyzed for optimal cut-offs and their effect on DFS. Differences in DFS rates and hazard ratios for DFS between cut-offs were statistically significant in SUVmax, MTV2.5, MTV3, TLG 2.5, TLG3, and TLG30%. Factors significantly related to DFS in univariate Cox regression were age, sex, stage, preoperative CEA, SUVmax, MTV2.5, MTV3, TLG2.5, TLG3, and TLG30%. Age, sex, preoperative CEA, and TLG2.5 (p = 0.009) sustained statistically significant difference in multivariate analysis. The 1-, 3-, and 5-year DFS rates for TLG2.5 ≤ 448.5 were 98.1%, 79.6%, and 74.8%, significantly higher than 78.4%, 68.5%, and 61.1% of TLG2.5 > 448.5, respectively (p = 0.012). TLG, a parameter indicating both the metabolic activity and metabolic volume, was the strongest predictor independently associated with DFS, among several PET parameters with statistical significance. These results suggest the potential prognostic value of preoperative ¹⁸F-FDG PET/CT in stage II/III resectable colorectal cancer.

This study evaluated the prognostic significance of FDG PET/CT in patients with nodal peripheral T-cell lymphoma (PTCL). We retrospectively reviewed patients with histologically confirmed nodal PTCL who underwent FDG PET/CT at baseline, after three cycles of first-line chemotherapy (interim), and at the end of therapy. Response was assessed visually using the Deauville 5-point scale (D5PS); scores of 1, 2, and 3 were considered PET-negative, and scores of 4 and 5 were considered PET-positive. The associations between FDG PET/CT findings and survival were assessed using Cox regression analysis. A total of 79 patients (44 males and 35 females; median age 56 years) were included in this study. In response assessment, 17 (22%) had an interim PET-positive result and 10 (13%) had an end-of-therapy PET-positive result. During a median follow-up of 50 months, 37 patients (47%) presented with disease progression and 30 patients (38%) died. The estimated 5-year progression-free survival (PFS) and overall survival (OS) were 57% and 64%, respectively. An interim PET-positive result was the only significant indicator of PFS. Higher International Prognostic Index and end-of-therapy PET-positive result were significant independent prognostic factors of OS. Interim and end-of-therapy FDG PET/CT responses based on D5PS are meaningful in predicting the outcomes of patients with nodal PTCL.

We describe the case of a 67-year-old man with lung cancer, who developed pulmonary tuberculosis (TB) following chemotherapy and subsequently exhibited a paradoxical reaction on positron emission tomography/computed tomography (PET/CT) after initiating antituberculosis therapy. While pulmonary consolidations improved with antituberculosis treatment, newly detected hypermetabolic mediastinal lymph nodes appeared on PET/CT. Based on the clinical course, we provisionally concluded that the mediastinal lymphadenopathy represented a paradoxical reaction. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) confirmed the diagnosis of TB. Clinicians added steroids and continued the antituberculosis medication, and follow-up PET/CT showed complete resolution of these lesions. This case highlights the importance of recognizing paradoxical reactions to antituberculosis therapy, when restaging PET/CT reveals divergent findings, with some tumor foci responding and other lesions appearing to be progressing.