As a pan-tumor tracer, chemokine receptor 4 (CXCR4)-directed [68Ga]Ga-PentixaFor is frequently utilized in patients with hematological malignancies. We aimed to evaluate the impact of recent surgical and interventional procedures on uptake. Patients undergoing [68Ga]Ga-PentixaFor PET/CT after prior surgical or interventional procedures were analyzed. Uptake at the procedural site was assessed visually and quantitatively (by applying maximum standardized uptake values [SUVmax], target-to-background ratios [TBR]). Quantitative parameters were compared across anatomical region groups (bone, organ, (sub-)cutaneous, muscle). We stratified patients demonstrating uptake in procedural sites into an early (0–30 days) and late group (≥ 31 days between intervention and [68Ga]Ga-PentixaFor PET). In patients with available [18F]FDG PET/CT, quantitative correlation analyses between both radiotracers were also performed. Among 425 [68Ga]Ga-PentixaFor PET/CT examinations, 87 prior invasive procedures (20.5
Gamma-ray water monitors (GWMs) are widely used for radioactive wastewater monitoring but can be inaccurate in mixed radionuclide conditions. This study compared radioactivity concentrations measured using a GWM and a high-purity germanium (HPGe) detector and evaluated the validity of derived conversion factors. Wastewater containing 131I and 177Lu with 177mLu impurity was sampled from storage tanks in a targeted radionuclide therapy facility. We then measured radioactivity concentrations using GWM and HPGe detectors. GWM reproducibility was evaluated, and the effects of sampling location and stirring were assessed. Conversion factors were derived from paired measurements and applied to independent samples. Radioactivity concentrations did not differ significantly between sampling locations or before and after stirring. GWM measurements showed high reproducibility (CV = 1.7
Structural magnetic resonance imaging (MRI) measures may relate to cognition differently depending on the underlying biological context. We examined the associations of global gray matter volume and cortical thickness with cognitive performance after stratification by amyloid positron emission tomography (PET) status. This cross-sectional study included 113 participants (mean age 76.3 ± 7.8 years; 68.1
The surgical management of primary hyperparathyroidism (PHPT) has shifted toward minimally invasive, targeted approaches. In this retrospective study the clinical outcomes, safety, and operative durations of three distinct surgical techniques were compared: radioguided occult lesion localization (ROLL), intravenous Tc-99 m sestamibi gamma-probe guidance (IV MIBI), and standard minimally invasive parathyroidectomy. This study is a single-center retrospective analysis of 178 patients who underwent surgery for parathyroid adenomas. Patients were categorized into three surgical cohorts: ROLL (n = 100), IV MIBI (n = 42), and standard minimally invasive parathyroidectomy (n = 36). Primary endpoints included operative duration, preoperative and 24-hour postoperative serum parathyroid hormone (PTH) and calcium levels, complication rates, and long-term surgical cure rates. A multivariate linear regression model was utilized to adjust for potential baseline confounding variables. The median operative duration was significantly shorter in the ROLL group (47 min) compared to both the IV MIBI group (87.5 min, p < 0.001) and the standard group (84 min, p < 0.001). Patients in the standard cohort presented with significantly higher preoperative PTH levels and larger adenoma diameters. Upon adjusting for confounders, the surgical method and preoperative PTH levels also remained independent predictors of operative duration (p < 0.05). There were no statistically significant differences among the groups regarding rates of early postoperative hypoparathyroidism or hypocalcemia. During long-term follow-up, very high cure rates were observed in all groups: a 100
To evaluate the agreement and reproducibility of SPECT/CT-derived AutoPlanar imaging compared with conventional planar imaging in 99mTc-pyrophosphate (99mTc-PYP) scintigraphy for transthyretin amyloidosis cardiomyopathy (ATTR-CM). We retrospectively analyzed 54 patients with suspected ATTR-CM who underwent 99mTc-PYP scintigraphy. Conventional planar imaging and SPECT/CT acquisition were performed at 1 h and 3 h after tracer injection. AutoPlanar images were generated from reconstructed SPECT/CT datasets. Visual assessment using the Perugini grading scale and semiquantitative evaluation using the heart-to-contralateral chest (H/CL) ratio were compared between conventional planar and AutoPlanar imaging. Exact agreement in Perugini scores between conventional planar and AutoPlanar imaging was observed in 90.7
To determine whether Q.Clear and VUE Point FX (VPFX) reconstructions obtained from the same brain [18 F]fluorodeoxyglucose positron emission tomography ([18 F]FDG PET) acquisition are quantitatively interchangeable, and to characterise the regional, reference-region and noise-texture dependence of any differences. We retrospectively analysed paired Q.Clear and VPFX reconstructions from 1,145 clinical brain PET folders. The reviewed protocol used a 10-min acquisition, Q.Clear QCFX-S with beta 150, SharpIR and no z-axis filter, and VPFX-S with 3 iterations, 16 subsets and a 4.0-mm filter. Digital Imaging and Communications in Medicine metadata were audited, and 1,022 readable same-examination pairs were processed in MATLAB R2026a and statistical parametric mapping version 25. A common transform estimated from mean(Q.Clear, VPFX) was applied to both reconstructions. Absolute and standardised uptake value ratio (SUVR) differences normalised to whole brain, cerebellum and pons were assessed voxel-wise and in Automated Anatomical Labelling atlas 3 regions. DICOM-derived local high-frequency and robust global coefficients of variation (CVs) were also compared. Q.Clear increased the whole-brain, cerebellar and pontine reference means by 0.953
Yttrium-90 (Y-90) radioembolization has become a key therapeutic option for liver malignancies and is expanding into extrahepatic applications. This study aims to provide a Y-90–focused, field-wide bibliometric map that links global research trends to practice-defining contexts and explicitly contrasts glass versus resin microspheres and primary versus metastatic liver disease. The Web of Science Core Collection was queried for articles and reviews from 2005 to 12 July 2024. CiteSpace, VOSviewer, and Bibliometrix were employed to visualize annual output, co-authorship and institutional networks, reference co-citation backbones, and keyword clusters and bursts. Studies were narratively classified by microsphere type (glass vs resin) and disease context (hepatocellular carcinoma vs metastatic liver cancers). The study analyzed 2,002 publications, revealing an annual growth rate of 8
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, characterized by the limited efficacy of current therapies and an urgent need for novel treatment strategies. Targeted radionuclide therapy (TRT) enables the selective delivery of radionuclides to tumor sites via specific ligands, integrating molecular targeting with cytotoxic radiation. Among these radionuclides, 177Lu, a β-emitter with moderate energy and suitable tissue penetration, offers a distinct advantage in theranostics, whereas 225Ac, an α-emitter with high linear energy transfer (LET) and an ultrashort path length, demonstrates superior efficacy against hypoxic and treatment-resistant tumor cells. Although no TRT agents have yet been approved for PDAC, multiple emerging targets are under active investigation, with several candidates entering early-phase clinical trials. This review systematically summarizes recent advances in 177Lu- and 225Ac-labeled radiopharmaceuticals for PDAC, comparing their physicochemical properties, biological effects, and translational potential. Future perspectives for TRT development are also discussed to facilitate its clinical application in PDAC.
Partial volume effects (PVE) in positron emission tomography (PET) imaging introduce quantification inaccuracies, particularly in small or heterogeneous lesions, necessitating precise correction methodologies. This study systematically evaluates the performance of statistical versus machine learning approaches in partial volume correction (PVC) across multiple PET reconstruction algorithms, including TrueX, TrueX + TOF, and Iterative + TOF. Phantom experiments were conducted across a broad range of lesion-to-background contrast ratios and lesion sizes to derive and validate exponential recovery coefficient (RC) fitting models. Additionally, advanced machine learning algorithms, including Random Forest, Support Vector Regression, and Gradient Boosting, were implemented to enhance PVC accuracy. The results demonstrate that Iterative + TOF reconstruction yielded the most consistent RC estimates, while machine learning-based PVC significantly outperformed traditional exponential fitting in minimizing residual errors. Among the machine learning models, Random Forest exhibited the lowest root mean square error (RMSE) and highest coefficient of determination (R²), indicating superior predictive accuracy and robustness. These findings underscore the potential of machine learning-driven PVC methodologies for standardizing PET quantification, thereby improving lesion characterization, therapy response assessment, and multi-center data harmonization.
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) provides a survival advantage in metastatic castration-resistant prostate cancer (mCRPC). However, the physiologically high PSMA-ligand uptake in salivary glands makes these organs susceptible to radiation damage. The aim of this study is to examine the changes occurring in salivary glands after PSMA-RLT and to evaluate their relationship with treatment-related parameters, including cumulative administered activity and number of RLT cycles. The study included 68 mCRPC patients who received 177Lu PSMA-617 treatment. Volume, surface area, density, and PSMA uptake levels were calculated for the parotid and submandibular glands in pre- and post-treatment imaging. Treatment-related changes and their associations with baseline imaging parameters, treatment timing, cumulative administered activity, and number of RLT cycles were statistically analyzed. After RLT, parotid glands showed significant decreases in SUVmean, volume, surface area, and PSMA total activity (all p < 0.001), whereas parotid density remained stable. Submandibular glands also demonstrated significant reductions in SUVmean, volume, surface area, PSMA total activity, and CT-derived density (all p < 0.001). In the exploratory correlation analyses, the number of RLT cycles and cumulative administered activity showed weak nominal positive associations with parotid density change; however, these associations did not remain statistically significant after Benjamini–Hochberg false discovery rate correction. BMI was not significantly associated with glandular SUVmean, HU measurements, or post-treatment glandular changes after correction for multiple testing. PSMA-targeted RLT was associated with significant imaging-detectable structural alterations and reductions in PET-derived glandular activity in the major salivary glands. CT-derived density significantly decreased in the submandibular glands, whereas parotid density remained stable. No baseline imaging-, BMI-, time-, or administered activity-related parameter remained significantly associated with post-treatment glandular changes after correction for multiple testing.
In this study, we aimed to evaluate the association between liver clearance values obtained from pre-treatment [⁹⁹ᵐTc]mebrofenin hepatobiliary scintigraphy and conventional liver function scores and biochemical parameters, and to perform an exploratory prognostic assessment of whether baseline clearance is associated with post-treatment outcomes, including overall survival, prior to ⁹⁰Y radioembolization. We also compared the functional assessment of the treatment region (based on mebrofenin uptake) with its anatomical CT volume (derived from [⁹⁹ᵐTc]macroaggregated albumin SPECT/CT) to determine the concordance between functional and volumetric data. Pre-treatment [⁹⁹ᵐTc]mebrofenin and [⁹⁹ᵐTc]MAA scintigraphies were performed in 19 patients scheduled to receive Yttrium-90 (90Y) microsphere therapy. Mebrofenin clearance was calculated, and its association with biochemical parameters and overall survival was examined. The functional definition of the planned treatment territory was estimated based on mebrofenin uptake, and this was compared with the anatomical volume of the same region on MAA SPECT/CT. Mebrofenin liver clearance showed significant (p < 0.05) negative correlations with pre- and post-treatment total and direct bilirubin levels and a positive correlation with post-treatment albumin. Clearance also demonstrated a strong inverse correlation with ALBI score (p < 0.05). Among biochemical changes, only the post-treatment change in direct bilirubin was significantly associated with clearance (p < 0.05). Functional and volumetric definitions of the treatment area showed strong correlation (ρ = 0.837, p < 0.001). In five patients with target ratio greater than 50
This Phase I/IIa study evaluated the safety, pharmacokinetics, internal radiation dosimetry, and image quality of cyclotron-produced ⁶⁸Ga-PSMA-11 synthesized using an automated module in a Japanese population. In this single-center trial, nine Japanese men (3 healthy volunteers, 6 prostate cancer patients) received a single intravenous injection of ⁶⁸Ga-PSMA-11 (4.0 MBq/kg). Safety, pharmacokinetics (blood/urine), and internal radiation dosimetry (serial PET/CT) were assessed. Diagnostic performance was evaluated by lesion detection rates and image quality by quantitative metrics, including noise-equivalent count (NEC), to optimize the protocol. No adverse events were observed. The automated synthesis process consistently yielded high-quality ⁶⁸Ga-PSMA-11, with a decay-corrected radiochemical yield of 2841 ± 584 MBq and a radiochemical purity > 99
Personalized tools for accurately predicting papillary thyroid carcinoma (PTC) patients’ response to initial 131I therapy are lacking. This study aimed to develop a machine learning (ML) model for prediction of 6–12 month therapeutic response after therapy. This study retrospectively enrolled 702 PTC patients undergoing initial 131I therapy. A hierarchical classification framework was designed: the first layer distinguished excellent response from non-excellent response (Non-ER), while the second layer further categorized Non-ER into indeterminate response, biochemical incomplete response, and structural incomplete response. Seven ML algorithms were utilized per layer. Feature selection was performed using recursive feature elimination. Model development employed nested five-fold cross-validation within the training set, with performance further evaluated on an independent testing set. The final model was benchmarked against the American Thyroid Association risk stratification system, interpreted via Shapley Additive exPlanations, and deployed as an interactive web tool. For the first-layer classification, the Random Forest model optimally identified Non-ER. For the second-layer classification, the Logistic Regression + Extreme Gradient Boosting fusion model excelled. The final model, built on 17 features, achieved a hierarchical F1 score of 0.849 and an overall accuracy of 69.7
To compare the clinical significance of incidental 18F-fluorodeoxyglucose (18F-FDG) uptake detected on silicon photomultiplier-based digital positron emission tomography/computed tomography (dPET) versus conventional positron emission tomography/computed tomography (cPET), focus on suspicious incidental lesions and incidental malignancies. This retrospective single-center study included patients who underwent cPET from April 2019 to March 2020 and dPET from June 2020 to May 2021. Epilepsy PET and cardiac PET examinations requiring prolonged fasting protocols were excluded. Suspicious incidental FDG uptake was defined as a lesion unrelated to the primary indication or previously known disease, showing visually increased uptake and explicitly recommended for further evaluation in the original radiology report because malignancy was considered a concern. Lesions for which only follow-up was advised were excluded. Organ-specific analyses were performed exploratorily. Detection rates, organ distribution, malignant outcomes, and maximum standardized uptake value (SUVmax) were compared between groups. A total of 1,815 cPET examinations and 1,769 dPET examinations were analyzed. Suspicious incidental FDG uptake was identified more often with dPET than with cPET (149/1,769 [8.4
This study evaluated differences in the expression of proteins related to glucose metabolism and somatostatin receptors (SSTRs) between primary tumors and distant metastatic lesions in differentiated thyroid cancer (DTC). We retrospectively analyzed 18 patients with DTC (mean age 56 ± 10 years) who had bone or soft tissue metastasis. Immunohistochemical staining of surgical specimens was performed to assess the expression of glucose transporter 1 (GLUT-1), hexokinase-2 (HK-2), and somatostatin receptor subtype 2 (SSTR-2). Protein expression was classified as negative, weakly positive, or strongly positive. Correlations between primary and metastatic lesions were evaluated using Spearman analysis. FDG SUVmax values were compared according to protein expression using the Mann–Whitney U test, and the association between iodine avidity and SSTR-2 expression was assessed using Fisher’s exact test. GLUT-1 expression was more frequent in metastatic lesions than in primary tumors (65
Internal dosimetry in nuclear medicine commonly assumes a fixed upright standing posture of subjects. The use of four recent therapeutic radionuclides with longer half-lives causes long exposure to patients during different daily activities and postures. This study aims to evaluate the effect of posture change on organ absorbed doses for seven radionuclides: diagnostic photon/positron-emitters (64Cu, 68Ga, 99mTc) and therapeutic alpha/beta-emitters (177Lu, 211At, 212Pb, 225Ac). Whole body Japanese adult male and female digital human phantoms (National Institute of Information and Communications Technology, Japan) in standing and sitting postures were used in this study. Based on the reference biodistribution of 177Lu-DOTATATE in kidneys, liver, spleen and remainder of the body, generated 28 time-integrated activity maps (seven radionuclides, two genders, two postures) were used for RT-PHITS Monte Carlo simulations to calculate organ absorbed doses. A comparative analysis of the organ absorbed doses between the two postures was specifically conducted for the liver, kidneys, and spleen. Large differences in organ absorbed doses between the two postures were observed for diagnostic radionuclides, with ⁹⁹ᵐTc exhibiting more than 15
Prognosis in small cell lung cancer (SCLC) remains poorly predicted by conventional staging and metabolic parameters. This study aimed to develop a positron emission tomography/computed tomography (PET/CT) based Radiomic Risk Score (Rad-Score), evaluate its independent prognostic value for overall survival (OS), and assess the clinical utility of an integrated model using Decision Curve Analysis (DCA). 143 SCLC patients (120 male, 23 female) who underwent pre-treatment staging 18F-fluorodeoxyglucose (18F-FDG) PET/CT between January 2012 and June 2024 were included. Using LIFEx (v25.06.1), 129 Image Biomarker Standardisation Initiative (IBSI) compliant radiomic features were extracted alongside standard metabolic parameters (SUVmax, SUVmean, MTV, TLG). After eliminating highly correlated features (|r|> 0.90), five key features were selected via tenfold cross-validation LASSO-Cox regression to construct the Rad-Score. Patients were stratified into Low and High Radiomic Risk groups. Independent prognostic factors were identified through Cox regression analyses, and the incremental value of the Rad-Score was assessed by hierarchical C-index comparisons and DCA. Median OS was 10.8 months (95
