BackgroundQuantitative bone SPECT/CT enables objective assessment of skeletal radiotracer uptake using standardised uptake values (SUVs) and related parameters. Advances in reconstruction, correction methods, calibration and detector technology have improved measurement reliability and expanded interest in oncological and benign skeletal applications. This review evaluates current clinical applications, technical limitations and future directions of quantitative bone SPECT/CT.MethodsPubMed was searched for English-language full-text human studies published from January 2015 to March 2025 using a reproducible Boolean strategy focused on quantitative or semi-quantitative bone SPECT/CT. Screening followed PRISMA 2020 principles. Thirteen primary studies were included in the qualitative synthesis; reviews, case reports, guidelines, position papers and other supporting publications were used only for narrative context.ResultsQuantitative bone SPECT/CT showed potential value for differentiating benign from malignant bone lesions, comparison with 18F-NaF PET/CT, longitudinal response assessment and prognostic evaluation before bone-targeted radionuclide therapy. Potential applications were also identified in condylar hyperplasia, fibrous dysplasia, vertebral compression fractures and degenerative joint disease. However, most studies were retrospective, single-centre and technically heterogeneous. Reported SUV thresholds were influenced by tumour type, lesion phenotype, uptake time, acquisition/reconstruction parameters, calibration, segmentation and recovery-coefficient methods, limiting transferability.ConclusionsQuantitative bone SPECT/CT is a promising technique for objective assessment of bone metabolism, but current evidence supports cautious use as an adjunct to morphology and clinical context. Prospective multicentre studies with harmonised protocols, risk-of-bias control and patient-relevant endpoints are required. Artificial intelligence, radiomics, advanced detectors and theranostics should currently be considered research opportunities rather than established applications.
AimWe evaluated whether Magnetic Resonance Imaging (MRI)-Derived T Stage independently predicts nodal disease on Prostate-Specific Membrane Antigen (PSMA) PET/CT in patients with high-risk primary prostate cancer, and developed a predictive model for clinical decision support.Materials and methodsMRI-derived T Stage, Prostate-Specific Antigen (PSA), Gleason score, age and PSMA node status were analysed using univariable and multivariable logistic regression in 152 men with high-risk primary prostate cancer who underwent pre-treatment multiparametric MRI and PSMA PET/CT. Model performance was assessed with area under the receiver operating characteristic (ROC) curve (AUC), calibration plots, and decision curve analysis. Subgroup analyses evaluated Gleason 3 + 4 and 4 + 3 disease separately.ResultsMRI T3b and T4 stages were independently and significantly associated with increased risk of PSMA-positive nodal disease (p < 0.001 and p = 0.016, respectively). T3a disease was not significantly independently associated with PSMA-positive nodal disease (p = 0.086). T3b remained an independent predictor even in Gleason 4 + 3 cases (p = 0.026; odds ratio ≈ 23.57). The final model (AUC = 0.863) was well-calibrated and demonstrated clinical net benefit on decision curve analysis. In our cohort, patients with PSA < 20 ng/mL, MRI-derived T2 disease, and Gleason score < 8 (including both 3 + 4 and 4 + 3 patterns) demonstrated a 0% rate of PSMA-positive nodal disease.ConclusionMRI-derived T stage T3b disease is a strong independent predictor of PSMA-positive nodal disease. These findings support guideline-based staging criteria and support the integration of MRI-derived T Stage into PSMA PET/CT triage workflows.
We report a case that combines several aspects of molecular diagnostics and clinical follow-up with innovative imaging of [89Zr]Zr-DFO-trastuzumab positron emission computed tomography (PET/CT) to depict human epidermal growth factor receptor 2 (HER2)-targeted tracer uptake in several metastatic sites in advanced platinum-resistant high-grade serous ovarian cancer (HGSOC). A 74-year-old woman underwent this procedure, and PET/CT images were interpreted alongside conventional biomarkers [CA125 and immunohistochemistry (IHC)] and contrast-enhanced computed tomography (CE-CT). PET imaging revealed intense tracer uptake in the primary ovarian tumour site (SUVratio 13.8), with corresponding HER2 + expression (3+) observed on the IHC of the primary tumour. Moreover, moderate uptake was observed in abdominal wall metastases (SUVratio 3.6) and near-background uptake in hepatic lesions (SUVratio 1.6), consistent with image-suggestive spatial heterogeneity in HER2-targeted tracer uptake. CA125 measurements corroborated early biochemical response, with values declining from 676 to 254 U/mL after six weeks of trastuzumab deruxtecan (T-DXd) treatment as third-line therapy. Follow-up CE-CT showed qualitative regression of [89Zr]Zr-DFO-trastuzumab-avid lesions, despite non-measurable disease by RECIST and a subsequent CE-CT imaging after 20 weeks demonstrated a mixed response pattern, without a clear relationship to pre-T-DXd [89Zr]Zr-DFO-trastuzumab uptake. This case study illustrates how integrating non-invasive [89Zr]Zr-DFO-trastuzumab PET molecular imaging with conventional radiology, IHC, and biochemical markers within the clinical pathway may support individualised therapeutic decision-making.
Objective:To investigate the correlation between baseline 1⁸F-FDG PET/CT metabolic parameters and progression-free survival (PFS) in EGFR-mutant lung adenocarcinoma receiving EGFR-TKI treatment, with subgroup analysis for exon 19 deletion (19del) and L858R mutations. Methods:This single-center retrospective study included 175 patients with pathologically confirmed EGFR-mutant lung adenocarcinoma who underwent baseline 1⁸F-FDG PET/CT prior to EGFR-TKI therapy between 2020 and 2023. Quantitative metabolic parameters, including SUVmax, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were measured. Progression-free survival was the primary endpoint. Survival analyses were performed using Kaplan-Meier estimates, log-rank tests, and Cox proportional hazards regression models, with prespecified subgroup analyses according to EGFR mutation subtype (19del vs. L858R). Results:The median follow-up duration was 48 months. In univariate analysis, higher SUVmax, SUVpeak, MTV, and TLG were significantly associated with shorter PFS (all P < .05), while MTV and TLG failed to reach statistical significanceOn multivariate Cox regression analysis, SUVmax remained independently associated with PFS [hazard ratio (HR) = 1.031, 95% confidence interval 1.001-1.059, P = .045]. Patients with EGFR 19del mutations demonstrated a significantly longer median PFS compared with those harboring L858R mutations (13.57 vs. 10.37 months, P = .02). Third-generation EGFR-TKIs were associated with a significant prolongation of PFS in the 19del subgroup (P < .05), whereas no significant benefit was observed in the L858R subgroup, these subgroup findings should be interpreted cautiously as preliminary exploratory observations limited by small sample sizes. Conclusion:Baseline 1⁸F-FDG PET/CT metabolic parameters, especially SUVmax, are independent prognostic biomarkers for PFS in EGFR-mutant lung adenocarcinoma patients receiving EGFR-TKIs therapy. The prognostic implications of metabolic imaging differ according to EGFR mutation subtype, and further large prospective cohorts are needed to validate our exploratory subgroup findings supporting an integrated approach combining metabolic imaging and molecular stratification for individualized risk assessment.
IntroductionSparse-view computed tomography (CT) reconstruction is crucial for clinical diagnostics, as reducing radiation exposure is essential to minimize risks to patients. Existing dual-domain reconstruction methods leverage both image and projection domains but often process them sequentially, overlooking their implicit correlations.MethodsTo address this limitation, we propose Cross-Domain TransNet, a Transformer-based dual-domain framework for sparse-view CT reconstruction. The proposed model captures long-range dependencies within each domain and integrates image and sinogram representations through a hybrid self-attention mechanism. In addition, a Convolution Fusion Layer (CFL) is introduced to enhance feature interactions and facilitate more effective utilization of dual-domain information.ResultsExtensive experiments on the NIH-AAPM dataset demonstrate the superior performance and generalization capability of the proposed method under various sparse-view settings. The results show that Cross-Domain TransNet consistently improves reconstruction quality, effectively suppresses noise, and reduces artifacts, outperforming both conventional reconstruction algorithms and state-of-the-art deep learning approaches.ConclusionCross-Domain TransNet provides an effective and robust solution for sparse-view CT reconstruction. By fully exploiting complementary information from both image and projection domains, the proposed framework enhances diagnostic image quality while supporting radiation dose reduction.
Synovial sarcoma is a rare and aggressive soft tissue malignancy that predominantly affects adolescents and young adults. Early diagnosis can be challenging due to nonspecific clinical presentation and the heterogeneous imaging appearance of these tumors. Multimodal imaging plays a central role in disease detection, characterization, staging, and treatment planning, and is increasingly used for treatment response assessment. We report the case of a 16-year-old girl presenting with progressive pain and functional limitation of the right shoulder, ultimately diagnosed with a giant synovial sarcoma arising in an uncommon anatomical location. The diagnostic work-up included a comprehensive imaging approach integrating ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and whole-body ^18F-FDG PET/CT. This multimodal strategy allowed accurate evaluation of tumor extent, assessment of possible bone involvement, and detection of regional lymph node disease. Following three cycles of combination chemotherapy with ifosfamide and doxorubicin, follow-up imaging demonstrated a reduction in tumor metabolic activity on ^18F-FDG PET/CT, consistent with an early metabolic response to therapy, despite the persistence of a relatively stable tumor volume on anatomical imaging. This case underscores the importance of an integrated imaging strategy in the management of pediatric soft tissue sarcomas and highlights the clinical value of combining complementary imaging techniques in rare and complex presentations. In particular, it illustrates how the coordinated use of multiple diagnostic modalities can optimize staging accuracy and support individualized treatment planning in pediatric patients with uncommon and large soft tissue tumors.
Background and ObjectivePositron Emission Tomography (PET) is widely used for assessing metabolic activity and diagnosing cancer. Due to the inherently high noise levels in PET data, advanced reconstruction algorithms are essential for accurate imaging. Convolutional Neural Networks (CNNs) within the Learned Primal-Dual (LPD) framework have shown good performance for PET reconstruction; however, the locality assumption imposed by CNNs can limit their ability to capture long-range contextual dependencies in sinogram data. Motivated by our previous work on transformer-based architecture for low-dose and low-count sinogram denoising, we comprehensively investigate the integration of attention mechanisms, both self-attention and cross-attention, within the LPD framework.MethodsWe propose and evaluate three novel transformer-based LPD architectures: the Dual-Domain Stacked Transformer-based LPD, which employs sinusoidal patches to model long-range dependencies in the dual domain (sinogram); the Dual-Domain Restormer-based LPD, a hybrid design that combines CNNs for fine-grained local feature extraction with transformers for global information exchange; and the Dual-Domain UNet-based LPD incorporating Cross-Attention mechanism, which augments the U-Net LPD with cross-attention to capture complementary information across image and sinogram domains. To enable robust transfer learning, we further introduce a system-aligned synthetic data generation process that replicates the MiniPET-3 system, our in-house preclinical PET scanner dedicated to small-animal imaging, incorporating realistic acquisition geometry, resolution blurring, positron range effects, and Poisson noise.ResultsEvaluations on synthetic data demonstrate that both the Stacked Transformer-based LPD and Dual-Domain Restormer-based LPD outperform the UNet-based LPD baseline in MSE and PSNR across all noise levels, with the Restormer additionally achieving higher SSIM at low noise. The UNet-based LPD incorporating a cross-attention mechanism also improves MSE and PSNR over the baseline, while exhibiting a slight reduction in SSIM, indicating a trade-off between pixel-wise accuracy and structural similarity. Trained exclusively on synthetic data, the proposed models generalize well to experimental measurements, producing high-quality reconstructions.ConclusionsOverall, this work highlights the promise of transformer-integrated LPD frameworks for enhancing PET reconstruction quality and robustness in low-count imaging settings.
Long axial field-of-view (LAFOV) PET scanners offer substantially higher sensitivity compared to conventional short axial field-of-view (SAFOV) systems, potentially enabling reduced injected activity, shorter acquisition times, and improved signal-to-noise ratios in brain imaging. However, given the geometric differences between these systems, it is important to assess whether these differences impact image quality and quantitative accuracy before translating established SAFOV protocols to LAFOV systems. This study has two goals: (1) to compare image quality (IQ) metrics between a SAFOV PET scanner (Siemens Biograph Vision) and a LAFOV PET scanner (Siemens Biograph Vision Quadra) using a Hoffman brain phantom, and (2) to quantify the effective axial sensitivity gain provided by the LAFOV system for brain imaging. MethodsTwo phantom experiments were performed: the first assessed IQ metrics and the influence of external background activity, while the second evaluated brain-specific sensitivity at different axial positions within the LAFOV scanner.ResultsOverall, IQ metrics were highly comparable between scanners and were minimally affected by external background activity. Positioning the phantom at the first detector ring of the LAFOV scanner yielded a 1.2–1.4× sensitivity increase relative to the SAFOV system, whereas positioning it at the axial centre resulted in a sensitivity gain of up to 3.4×.ConclusionThese findings indicate that LAFOV PET systems maintain quantitative consistency with SAFOV scanners while offering higher sensitivity. This supports the development of optimized PET imaging protocols to reduce injected activity and radiation exposure, thereby improving safety and enabling broader inclusion of vulnerable populations in brain PET studies.
PurposeNuclear medicine (NM) often functions as an isolated diagnostic island within hospitals, resulting in the underutilization of high-value molecular imaging resources despite their significant clinical potential. This paper proposes a conceptual management-driven framework, termed the Management-Driven Integration Loop, to break down these silos and integrate NM into the broader hospital ecosystem to potentially enhance clinical decision-making and operational efficiency.MethodsA comprehensive integration framework was developed based on four strategic pillars: strategic resource allocation, process re-engineering, performance leverage, and brand building. The framework introduces specific administrative interventions, including the establishment of satellite workstations to improve clinical proximity, the creation of a Clinical-NM Liaison role to bridge interdisciplinary gaps, and the implementation of a multidimensional Total Performance Index (TPI) to align incentives.Framework componentsIntegration is envisioned through protocol-based clinical pathways embedded in electronic health records and structured Multidisciplinary Team (MDT) collaboration, ensuring NM expertise may inform treatment planning. The framework incorporates a continuous feedback loop to track clinical impact, including diagnostic upstaging and the avoidance of unnecessary procedures. By proposing a shift from volume-based metrics to the TPI, administrators can weight qualitative clinical contributions and interdisciplinary collaboration alongside traditional procedural throughput.ConclusionsTransforming nuclear medicine into a central strategic asset requires deliberate administrative intervention. While implementation depends on overcoming institutional, technical, and regulatory barriers, this management-driven integration loop aims to bridge the gap between technological potential and clinical impact, improve patient outcomes through precision diagnostics, and strengthen institutional positioning as centers of excellence.
PurposeAfrica faces a projected doubling of cancer burden by 2040, yet access to radionuclide therapies remains critically limited. This systematic review quantifies the availability, accessibility, and economic feasibility of therapeutic nuclear medicine across 54 African nations.MethodsThis study combined a PRISMA 2020-compliant systematic literature review with secondary database analysis. A comprehensive search was conducted across PubMed/MEDLINE, Scopus, Web of Science, and African Journals Online (January 2022–March 2026). Epidemiologic and infrastructure data were additionally obtained from GLOBOCAN 2022 and the International Atomic Energy Agency (IAEA). Risk of bias was assessed using the modified Newcastle–Ottawa Scale for peer-reviewed studies and the AACODS checklist for gray literature.ResultsOf 2,847 records identified, 47 studies met the inclusion criteria. I-131 therapy for thyroid cancer is available in only 28/54 countries (51.9%), while Lu-177-PSMA for prostate cancer is available in only seven countries (13.0%). Local radiopharmaceutical production reduces therapy costs by 93%–96% compared with imported agents. Africa has approximately 0.18 nuclear medicine physicians per million population vs. 3.1 in Europe. The cost reduction ratio for local vs. imported Lu-177-PSMA is 1:28.3 (US$1,500–3,000 vs. US$42,500).ConclusionRadionuclide therapy availability in Africa is profoundly inadequate relative to disease burden. Economic modeling demonstrates that local production and regional hub models can achieve cost reductions exceeding 90%, making therapies economically feasible for resource-limited settings. Targeted investment in cyclotron infrastructure and workforce development is urgently needed.
BackgroundAccurate staging of Hodgkin lymphoma in children is important for selecting appropriate therapies. However, evaluation of Ann Arbor staging criteria on whole-body 18F-FDG PET scans is time-consuming and subject to reader-dependent variability.ObjectiveTo determine if a novel computer-aided staging tool can improve the time-efficiency and accuracy of Ann Arbor staging.Methods18F-FDG PET/MRI scans of fifty-six pediatric patients were divided into two groups with matched Ann-Arbor stages. Group 1 was staged via traditional inspection and Group 2 was staged with a newly developed web-based staging tool by one radiology resident, four radiologists and two nuclear medicine physicians. An additional radiologist and nuclear medicine physician jointly established the reference standard. The time to generate the Ann Arbor score was compared between group 1 and 2 with the Wilcoxon Rank-Sum test, and agreement with the reference standard was assessed with Cohen's kappa analysis. In addition, staging time was correlated with reader experience level, measured as the number of PET cases interpreted per year, using linear regression analysis.ResultUse of the tool significantly reduced Ann Arbor staging time (10.8 ± 6.33 min) compared to traditional staging without the tool (13.87 ± 8.16 min; p = 0.001). The greatest reduction in staging time was observed for the radiology resident (17.63 ± 2.3 min with the tool and 21.5 ± 3.3 without the tool), followed by radiologists (13.63 ± 2.5 min with the tool and 18.03 ± 2.6 without the tool), while no significant change was observed for nuclear medicine physicians (1.45 ± 0.82 min with the tool and 1.39 ± 1.12 without the tool). Agreement with the reference standard improved with tool assistance (κ = 0.616) compared to traditional staging without the tool (κ = 0.945 with the tool). Linear regression demonstrated a significant inverse association between reader experience and time saved using the tool (β = −0.812, p < 0.001; R² = 0.66), indicating greater benefit for less experienced readers.ConclusionThe computer-aided staging tool significantly improved time-efficiency and accuracy of Ann Arbor staging, especially for less experienced readers. We provide the tool as a freely accessible web resource.
IntroductionAnti-1-amino-3-[18F] fluorocyclobutane-1-carboxylic acid (18F-fluciclovine; anti-3-[18F] FACBC) is an amino acid positron emission tomography (PET) tracer used for the evaluation of brain tumors in cases of suspected or diagnosed glioma. While its uptake characteristics in brain tumors have been reported, systematic data on background uptake in normal-appearing head tissues including extracranial structures remain limited. The purpose of this study was to characterize the background uptake of 18F-fluciclovine in intracranial and extracranial head tissues in patients with suspected malignant glioma.Methods18F-fluciclovine PET/CT images from 20 patients with suspected malignant glioma were retrospectively analyzed. Standardized uptake values (SUVs) were measured in 24 predefined head regions, and inter-regional differences were assessed using one-way ANOVA with Tukey's HSD post hoc test. Time–activity curves were generated in 15 patients for dynamic evaluation of temporal uptake patterns. In the overall cohort, 8 patients also underwent 11C-methionine PET/CT, and SUVs were compared using paired t-tests and their correlations were assessed using Pearson's correlation coefficient. Statistical significance was set at P < 0.05.Results18F-fluciclovine uptake in the cerebral hemispheres was generally low, with the lowest SUVmean observed in white matter (0.15 ± 0.04). Cortical uptake was uniformly low, with SUVmean and SUVpeak of 0.28 ± 0.06 and 0.31 ± 0.07, respectively, and no significant interlobar differences. Among other brain regions, SUVmean was highest in the cerebellar vermis (0.46 ± 0.09), followed by the pons, cerebellum, thalamus/basal ganglia, midbrain, and medulla. Dynamic imaging demonstrated low and stable brain uptake, whereas the pituitary and parotid glands exhibited early peak uptake followed by washout. In patients who also underwent 11C-methionine PET, 11C-methionine showed significantly higher uptake in all brain regions, whereas 18F-fluciclovine was higher in venous structures, skeletal muscle, and the nasal cavity.ConclusionThis study establishes a detailed baseline of background 18F-fluciclovine uptake in normal-appearing intracranial and extracranial head tissues in patients with suspected glioma. These findings may facilitate the distinction between physiological and pathological uptake and inform the interpretation of 18F-fluciclovine PET in the assessment of brain tumors.
BackgroundNuclear medicine (NM) is being embraced by undeveloped countries as a specialty. Due to the high costs involved in establishing new NM and radiopharmacy centres, proper planning is essential. This study describes the pattern of radiopharmacy services and staffing in NM departments in South African Academic hospitals (SAAHs); which can aid planning of new NM and radiopharmacy centres in similar settings.MethodsThe study was retrospective, descriptive, and quantitative. An anonymized questionnaire was sent via Survey Monkey® to the nine SAAHs to determine nuclear medicine patient numbers by scan type, identify cameras, equipment, staffing levels, commonly used radiopharmaceuticals, and define the basic requirements for establishing new facilities.ResultsThe response rate was 78% (7/9 hospitals). Average number of NM patients seen per hospital was 7,040 for 2022. All hospitals had SPECT-CT cameras; six had PET-CT cameras and one referred PET patients to a private hospital. All hospitals had NM physicians (range 2–13, average 5) and at least one medical physicist (range 1–4). Only two hospitals had radiopharmacists (only one in each).ConclusionTo promote optimal patient services and support research in SAAHs, norms must be developed that are applicable to Africa. Appropriate staff quotas and equipment are required for the African setting to promote optimal use of radiopharmaceuticals and enable NMs to operate to their full potential. Key things to help in planning and establishing new radiopharmacy centers include; adopting centralized radiopharmaceutical production and aligning staffing with international guidelines.
BackgroundPrimary aldosteronism (PA) is an endocrine disorder caused by autonomous aldosterone hypersecretion from the adrenal zona glomerulosa, causing sodium retention, plasma volume expansion, and suppressed renin activity, manifesting as hypertension with/without hypokalemia. Aldosterone-producing adenomas (APAs), a common PA subtype, are typically unilateral and solitary; bilateral involvement is rare. We report a patient with hypertension and bilateral multiple adrenal adenomas. 68Ga-Pentixafor PET/CT proved crucial for detecting and subtyping lesions, highlighting its significant diagnostic utility for APA subtyping.Case presentationA 62-year-old male presenting with nausea, generalized fatigue, and poorly controlled hypertension (10-year history; max BP 200/110 mmHg) was admitted. Bilateral adrenal CT, which revealed multiple bilateral adrenal adenomas, raised clinical suspicion for primary aldosteronism. To confirm the diagnosis, 68Ga-Pentixafor PET/CT imaging was performed, which identified five nodules with varying intensities of tracer uptake bilaterally.Conclusion68Ga-Pentixafor PET/CT integrates structural and functional assessment, transcending the limitations of CT and adrenal vein sampling (AVS), thereby demonstrating substantial clinical value for evaluating multifocal or bilateral adrenal pathologies.
ObjectiveOn dual-tracer positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) and fibroblast activation protein inhibitor ([⁶⁸Ga]Ga-FAPI-04), discordant lesions (FDG+/FAPI-) in aggressive neuroendocrine neoplasms (NENs) are linked to shorter progression-free survival (PFS). This study evaluated the prognostic value of such lesions in comparison to histological fibroblast activation protein (FAP) expression from a clinically obtained biopsy and their impact on PFS.Methods23 patients with aggressive NENs underwent both [¹⁸F]FDG and [⁶⁸Ga]Ga-FAPI-04 PET/CT as well as biopsy within a short period of time. PET parameters [standardized uptake values (SUV): SUVmax, SUVmean, SUVpeak] were measured, as were tumor volume (TV), and total lesion uptake (TLU = TV × SUVmean). FDG+/FAPI- lesions were identified. FAP expression was assessed immunohistochemically using the immunoreactive score (IRS-FAP). Correlations between PET metrics, IRS-FAP, and FDG+/FAPI- lesions were analyzed. Cox regression and log-rank test were used to evaluate associations with PFS.ResultsIRS-FAP correlated significantly with TV ([¹⁸F]FDG: p=0.0165; [⁶⁸Ga]Ga-FAPI-04: p = 0.0181) and TLU ([¹⁸F]FDG: p = 0.0170; [⁶⁸Ga]Ga-FAPI-04: p = 0.0253). There was no significant correlation for IRS-FAP with SUV parameters. FDG+/FAPI- lesions were found in 9/23 patients and associated with significantly shorter PFS (4 vs. 10 months, HR: 3.383, p = 0.0015). [¹⁸F]FDG-TV and [¹⁸F]FDG-TLU correlated with PFS, but IRS-FAP showed no significant association with either PFS or FDG+/FAPI- lesions.ConclusionsFAP expression on immunohistochemistry obtained from a single biopsy site does not predict discordant PET/CT findings. In contrast, the presence of FDG+/FAPI- lesions is a strong prognostic factor for reduced PFS. Thus, dual-tracer PET/CT may offer superior risk stratification compared to single-lesion histological FAP assessment in aggressive NENs.
IntroductionProstate specific membrane antigen (PSMA) is a type II transmembrane protein overexpressed in the neovasculature of some pancreatic ductal adenocarcinoma (PDAC). PET/CT can detect this expression and has now become an essential tool in this context. However, this antigen can also be expressed by other neoplasms. While this may create diagnostic uncertainty, it could also open therapeutic opportunities.Clinical caseHere we describe a case in which a PET/CT performed to restage a patient with prostate adenocarcinoma experiencing biochemical recurrence revealed the coexistence of a PDAC.Literature reviewA literature review aimed to summarize the bibliographic evidence on the use of this technique in this setting, which is relatively uncommon.ConclusionProstate-specific membrane antigen can be overexpressed in PDACs. This finding may offer potential for theranostic applications
Background:Transarterial radioembolization (TARE) using Yttrium-90 microspheres has emerged as a promising locoregional therapy for patients with advanced hepatocellular carcinoma (HCC). However, the efficacy and safety of TARE compared to conventional treatments remain uncertain. This meta-analysis aimed to comprehensively evaluate the survival outcomes and safety profile of TARE in advanced HCC. Methods:A systematic literature search was conducted in PubMed, Embase, Cochrane Library, and Web of Science up to May 2025, following the PRISMA guidelines. Studies comparing TARE with conventional or systemic therapies in advanced HCC were included. Pooled hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS), and odds ratios (ORs) for adverse events (AEs) were calculated using random-effects models. Subgroup and meta-regression analyses explored the influence of study design, liver function (Child-Pugh, ALBI grade), and combined therapies. Results:Forty studies encompassing over 10,000 patients were included. TARE significantly improved OS (pooled HR = 0.72, 95% CI 0.63-0.83) and PFS (pooled HR = 0.78, 95% CI 0.69-0.89) compared with controls. Rates of grade ≥3 adverse events were lower in the TARE group (pooled OR = 0.74, 95% CI 0.59-0.93). Subgroup analyses indicated consistent benefits across retrospective and prospective studies, and in patients with Child-Pugh A-B liver function. Meta-regression revealed that younger age and higher objective response rate were associated with improved outcomes. Conclusion:TARE with Yttrium-90 microspheres confers significant survival benefits and acceptable safety in advanced HCC. These findings support the integration of TARE into multidisciplinary management strategies for advanced HCC, particularly in patients unsuitable for surgical or systemic therapies. Systematic Review Registration:PROSPERO (CRD420251163947).
Introduction:The ISOLPHARM project has the aim of developing novel radiopharmaceuticals using the wide choice of radionuclides produced by Isotope Separation OnLine (ISOL) at LNL-INFN in the SPES facility, which is currently nearing completion. One of the most promising candidates for Targeted Radionuclide Therapy (TRT) is the beta-emitting radiometal silver-111, obtainable carrier-free irradiating a uranium carbide target with a proton beam and applying the ISOL technique. Until SPES will become fully operational, small quantities of silver-111 are produced by the TRIGA Mark II nuclear reactor hosted by the LENA facility of the University of Pavia to begin the preclinical research. The present work concerns the first radiobiological experiment involving silver-111.Methods:Different activity concentrations of the aforementioned radiometal are administered to the UMR-106 rat osteosarcoma and LNCaP human prostate cancer cell lines through the culture medium. The survival curves after four and six days of exposure, as well as the recurrence of foci of DNA repair proteins and micronuclei, are evaluated as a function of the absorbed dose and compared to the control cultures. According to the MIRD formalism, a dosimetric analysis is performed taking advantage of cellular S-values simulated with the Monte Carlo code Geant4 in a generalized cell geometry. This makes it possible to relate the experimental outcome, namely the surviving cells after the exposure cycles, to the absorbed dose in the cell nucleus or in the whole cell environment.Results and discussionThe results show a difference in the response of the two cell lines, probably due to the thresholds of their DNA repair pathways, and highlight a possible weakness of the linear-quadratic model when applied to this kind of radiobiological studies.
Purpose:Oncological patients regularly undergo PET/CT re-staging, which requires a report that outlines their current disease status and highlights relevant changes compared to the previous PET/CT. Large language models (LLMs) may be helpful with documentation in the future. This study is a pilot on LLM performance, focusing on test-retest stability and reproducibility. Methods:Three textbook melanoma follow-up cases of increasing complexity (involving one to eight organs) were selected. From standardized text-only prompts (no imaging data), follow-up reports were written by GPT-4o, Claude Sonnet 4 (each producing three independent revisions), and three nuclear medicine residents. This yielded nine reports per case (27 in total). Six blinded nuclear medicine experts (three internal, three external) performed test-retest evaluations of report quality and authorship identification. Results:The cosine similarity analysis revealed high intra-case coherence (mean: 0.599-0.727) regardless of authorship. The external human readers consistently rated reports higher than the internal human readers. The LLM-generated reports received comparable or superior ratings to human reports, with Claude achieving the highest external reader scores (mean 0.926, standard deviation 0.263, on a 0-1 scale). Human performance declined with case complexity, while Claude, in particular, improved. The external readers significantly preferred the LLM impressions (Fisher's exact test, p = 0.005). Neither the human nor LLM readers reliably identified authorship (balanced accuracy 0.343-0.500). Conclusion:In this pilot, blinded expert evaluation demonstrated that current LLMs can generate reports for melanoma [18F]fluorodeoxyglucose PET/CT of comparable quality to human-authored reports from text prompts in this study. High test-retest stability was obtained. Larger future studies will be required to confirm these findings.
