We compared a novel deep learning (DL)-based quantification software (BTXBrain) with an established platform (Q.Brain) for quantitative perfusion single photon emission computed tomography (SPECT) in patients with clinically confirmed neuropsychiatric systemic lupus erythematosus (NPSLE). This retrospective exploratory inter-platform comparison study included patients with clinically established NPSLE who underwent brain SPECT with technetium-99m ethyl cysteinate dimer (99mTc-ECD). SPECT datasets were reprocessed using BTXBrain and Q.Brain. Regional perfusion estimates were compared across predefined cortical territories using paired analyses, variance ratio assessments, and Kendall’s tau correlation analysis. A total of 540 paired regional and hemispheric evaluations from 30 NPSLE patients were successfully processed and analyzed. BTXBrain and Q.Brain unveiled systematic, region-specific divergence in perfusion metrics. BTXBrain yielded higher standardized uptake value ratio values than Q.Brain in frontal (mean difference 0.081, p < 0.001), posterior cingulate (0.090, p < 0.001), medial temporal (0.333, p < 0.001), and occipital regions (0.078, p < 0.001). Conversely, a reversed trend was observed in the right lateral parietal cortex (-0.056, p = 0.009). Variance ratio analysis confirmed that the DL-based approach introduces a significantly different data dispersion profile (p < 0.05 across multiple macro-regions), while meaningful cross-platform correlation was restricted to specific territories, such as the left posterior cingulate cortex (τ = 0.44, p = 0.002). BTXBrain and Q.Brain are not directly interchangeable in patients with NPSLE. Consequently, rather than a generic drop-in replacement, the routine clinical adoption of DL-driven SPECT quantification requires software-specific reference thresholds and further calibration before cross-platform use.
Positron emission tomography/computed tomography (PET/CT) provides biological information complementary to magnetic resonance imaging (MRI) in the evaluation of cerebral gliomas. Among available radiotracers, 11C-methionine is a representative amino acid tracer that helps detect and delineate glioma tissue because of increased tumor uptake and low physiologic uptake in the normal brain. In contrast, 11C-acetate may reflect acetate metabolism, astrocytic activity, and reactive astrogliosis in the tumor microenvironment. Therefore, dual-tracer imaging using 11C-acetate and 11C-methionine may provide complementary information for the noninvasive characterization of gliomas. This pictorial essay presents representative cases of adult-type diffuse gliomas classified according to the 2021 World Health Organization (WHO) classification. The cases include astrocytoma, isocitrate dehydrogenase (IDH)-mutant, central nervous system (CNS) WHO grades 2–4; glioblastoma, IDH-wildtype, CNS WHO grade 4; and oligodendroglioma, IDH-mutant and 1p/19q-codeleted, CNS WHO grades 2–3. Side-by-side comparison of MRI, 11C-acetate PET, and 11C-methionine PET demonstrates a gradual increase in uptake of both tracers across the IDH-mutant astrocytoma spectrum. Glioblastoma, IDH-wildtype, shows markedly increased uptake of both tracers. In contrast, oligodendrogliomas show a methionine-dominant discordant pattern, with intense 11C-methionine uptake and relatively lower 11C-acetate uptake. These representative imaging patterns illustrate the complementary value of dual-tracer PET for visualizing biological heterogeneity in adult-type diffuse gliomas.
This study aimed to establish a fully automated radiosynthesis procedure for [18F] AlF-NOTA-FAPI-04 using the CFN200 multifunctional module, optimize key reaction parameters to improve labeling efficiency, and preliminarily validate its in vivo biological affinity and quality via a translational proof-of-concept PET/CT study. Reaction parameters including precursor amount, AlCl₃ volume, reaction temperature and reaction time were sequentially evaluated and optimized. Quality control including appearance, pH, radiochemical purity, radionuclidic identity, activity, bacterial endotoxins, sterility, ethanol content and residual acetonitrile were performed. Preliminary PET/CT imaging was conducted in a patient with pancreatic cancer for comparison with [18F] FDG. The study was registered with the Chinese Clinical Trial Registry (ChiCTR2300077391). The total synthesis time was approximately 25 min, yielding a decay-corrected radiochemical yield of 29.38 ± 3.3
Amyloid positron emission tomography (PET) is central to the biological diagnosis and staging of Alzheimer’s disease (AD), yet longitudinal data for [¹⁸F]Florapronol remain limited. We evaluated whether baseline [¹⁸F]Florapronol amyloid burden is associated with 4-year [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) metabolic neurodegeneration in amnestic mild cognitive impairment (MCI). Twenty-nine patients with amnestic MCI were enrolled; 16 (55.2
To evaluate the prognostic value of 18F-FDG PET/CT metabolic parameters—specifically SUV, MTV, and TLG—integrated into the TNM stage IV classification for patients with metastatic non-small cell lung cancer (NSCLC). We retrospectively analyzed 272 consecutive patients with metastatic NSCLC who underwent baseline 18F-FDG PET/CT. Metabolic parameters (SUVmax, SUVmean, MTV, and TLG) were measured for both the whole-body tumor burden (wb) and the metastatic component (m). Statistical analysis included univariate and multivariate Cox regression to identify independent predictors of overall survival (OS), and the Lausen test to dichotomize continuous metabolic variables for Kaplan–Meier survival curves. Univariate analysis showed that age, stage IV (A vs. B), and all metabolic parameters were significantly associated with OS. To address collinearity, a multistep multivariate approach selected SUVmax_m and MTV_wb as the most robust metabolic predictors. The final multivariate model confirmed that stage IV (p = 0.039), age (p = 0.024), SUVmax_m (p = 0.002), and MTV_wb (p < 0.001) were independent prognostic factors. Notably, patients in stage IVA with high MTV_wb (> 62.35 ml) and those in stage IVB with low MTV_wb (≤ 933.30 ml) exhibited similar intermediate survival rates, whereas patients in stage IVA with low MTV_wb and those in stage IVB with high MTV_wb showed the highest and lowest OS, respectively. Metabolic 18F-FDG PET/CT parameters, particularly MTV_wb and SUVmax_m, significantly refine the prognosis of stage IV NSCLC beyond traditional TNM subcategories, highlighting the importance of metabolic tumor burden in metastatic disease.
This study aimed to evaluate the real-world effectiveness, survival outcomes, and safety profile of [177Lu]Lu-PSMA radioligand therapy (PSMA RLT) in an Asian cohort of patients with metastatic castration-resistant prostate cancer (mCRPC). This retrospective patient-based cohort study included 14 patients with mCRPC who underwent [177Lu]Lu-PSMA RLT between November 2020 and February 2025. Biochemical response was defined as a ≥ 50
PSMA PET/CT has a comparable accuracy to multiparametric MRI for detecting intra-prostatic lesions. However, data are limited regarding the value of uptake intensity and modified PRIMARY-like score using 99mTc-HYNIC-PSMA-11 SPECT/CT for localization of the intra-prostatic tumor, correlated with trans-rectal ultrasonography-guided (TRUS) biopsy histopathological findings. In this retrospective study, 99mTc-HYNIC-PSMA-11 SPECT/CT scans of 97 treatment-naïve patients referred for staging were assessed in a blinded manner. The tumor-to-liver ratio (TLR) was calculated as the highest prostate tumoral uptake relative to the liver, and, for each patient, a modified PRIMARY-like score was reported. Each prostate gland was divided into six sextants according to the miTNM criteria, and the readers were asked to indicate whether the tumor involved each sextant. The results of the systematic biopsy were correlated with the scan results. The patients had a mean age of 67.0 ± 7.3 years and a PSA level of 24.4 ± 25.6. Of the 582 evaluated sextants, 354 (60.8
This study investigates the prognostic impact of metastatic disease volume on clinical outcomes in metastatic castration-resistant prostate cancer (mCRPC) patients treated with [¹⁷⁷Lu]Lu-PSMA-617 radioligand therapy ([177Lu]Lu-PSMA-617 RLT), aiming to refine patient selection and optimize treatment strategies. This study included 264 mCRPC patients who received a taxane-based therapy and at least one cycle of [177Lu]Lu-PSMA-617 RLT at Mayo Clinic between October 2017 and February 2024. Patients were stratified into high-volume (n = 176) or low-volume (n = 88) disease groups per CHAARTED criteria (visceral metastases or ≥ 4 skeletal lesions, with one beyond the vertebral bodies/pelvis). Primary endpoints were overall survival (OS) and PSA response rate (PSA-RR, ≥ 50
Thulium is a heavy lanthanide and the second-least abundant rare-earth element in the lanthanide series. Out of 35 isotopes of thulium, only two isotopes, 171Tm and 170Tm, have relatively longer half-lives of 701 days and 128 days, respectively, and 169Tm is the most stable isotope of thulium. The longest half-life of 170Tm provides its logistical benefit to supply thulium worldwide without losing its activity. 170Tm is expected to cause low bone marrow toxicity because it has lower beta energy than other radionuclides. Thulium can be a promising radionuclide for bone pain palliation, considering its half-life as well as beta and gamma radiation. A thulium-based laser is used in the resection of tumours and has limited application as a diagnostic agent in the military, medicine, and meteorology. The well-tolerated dose of the thulium-EDTMP complex is 370 MBq in a patient having bone pain associated with skeletal metastasis. This article aims to review and discuss the current state of knowledge on the ecotoxicological, toxicological, and pharmacological properties of thulium and provide a foundation for further research on thulium as a bone pain palliator.
The 5-hydroxytryptamine 7 receptor (5-HT₇R) is overexpressed in glioblastoma and represents a promising imaging target. This study aimed to design, synthesize, and evaluate technetium-99m-labeled pyridylpiperazine derivatives as potential 5-HT₇R-targeted SPECT radiotracers. Two ligands (8 and 12) were synthesized and radiolabeled with the fac-[⁹⁹ᵐTc]Tc(CO)₃⁺ core. Radiochemical purity and stability were assessed by RP-HPLC and TLC. Lipophilicity (log D) was determined using the octanol/PBS method. In vitro binding and specificity were evaluated in U87 MG, SKOV-3, HT-29, and A549 cell lines, including blocking studies. Affinity parameters were obtained from saturation binding assays. In vivo biodistribution and imaging were conducted in normal mice and U87 MG xenograft models. Both radiotracers showed high radiochemical purity (> 96
Unlike whole-tumor summary metrics, voxel-wise metrics in positron emission tomography (PET) and magnetic resonance imaging (MRI) capture tumor heterogeneity. This study aimed to determine the voxel-wise repeatability of the standardized uptake value (SUV), apparent diffusion coefficient (ADC), and SUV/ADC ratio, compared with whole-tumor summary metrics, on 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET/MRI. Ten patients with newly diagnosed cervical cancer underwent two [18F]FDG-PET/MRIs 1–7 days apart. In MIM version 6.7, cervical tumor volumes of interest (VOIs) were manually delineated on PET images and ADC maps for both sessions. A deformable registration algorithm was run, using either the first session PET (PET1) or ADC (ADC1) VOI as the deformation target for the other three VOIs. SUV, ADC, and SUV/ADC values were extracted for each voxel. Intraclass correlation coefficients (ICCs) and Bland-Altman statistics were calculated. Statistical significance was assessed via the Wilcoxon signed rank test. SUV had better voxel-wise relative repeatability coefficients (RC-rel) for the ADC1 versus PET1 target (50.2
