OBJECTIVES:This study aimed to investigate the utility of age-specific cutoff values for triangular fibrocartilage complex (TFCC) injuries. METHODS:This study included 42 patients with TFCC injuries and 20 healthy volunteers. Each group was stratified into young and middle-aged groups using the cutoff age of 30. All participants underwent magnetic resonance imaging using a 1.5T scanner, and T1 and T2 values were measured at the articular disc and ulnar styloid attachment. Group comparisons by age (young vs. middle-aged) and condition (healthy vs. injured) were performed using the Mann-Whitney U test with Bonferroni correction. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance in distinguishing between healthy and injured groups. The area under the ROC curve (AUC) with and without age stratification was compared using the DeLong test. RESULTS:In the comparisons between the age groups, the T2 values at the ulnar styloid attachment were significantly lower in the healthy middle-aged group than those in the healthy young group (p = 0.006). In the comparisons between the condition groups, most T1 and T2 values were significantly higher in the injury group than those in the healthy group, (p < 0.0001 to 0.008). Age stratification, particularly for T2 values, improved AUCs from 0.80-0.87 to 0.85-1.00. CONCLUSION:Age-specific quantitative evaluation, particularly based on T2 cutoff values, may be useful for the diagnosis of TFCC injuries. ADVANCES IN KNOWLEDGE:The use of age-specific T2 cutoff values appears to improve the diagnostic performance of TFCC injury compared with non-age-stratified assessment.
Particle therapy can offer physical and biological advantages over conventional photon radiotherapy, yet its widespread adoption remains limited by the cost, scale, and complexity of the accelerators and rotating gantries involved. Upright patient positioning with fixed-beam delivery has re-emerged as a potential alternative that may simplify particle therapy systems. Here we consider upright, gantry-less particle therapy through the lens of philosopher Thomas Kuhn's five criteria for scientific change: (1) simplicity, (2) scope, (3) fruitfulness, (4) consistency, and (5) accuracy. Eliminating rotating gantries stands to improve simplicity by reducing mechanical complexity, weight, and maintenance requirements. This in turn should enable more robust and modular treatment rooms. Early studies also suggest that upright positioning has broad scope: it can reproduce most beam geometries achieved using gantries and appears feasible across multiple anatomical sites. Upright treatments may be fruitful in terms of reducing capital, construction, and operational costs. They will also bring opportunities for technological innovation and potentially for improved patient throughput due to faster ingress and egress. Regarding consistency, upright treatment postures more closely match normal, everyday physiology and are often associated with greater comfort for certain patient groups. Finally, in terms of accuracy, preliminary studies suggest suitable setup reproducibility and comparable treatment planning quality. Upright particle therapy therefore represents a promising alternative delivery model. Further treatment-planning studies, health-economic analyses, and prospective clinical trials are warranted to determine the role of upright systems alongside or in place of gantry-based systems.
Soft tissue lesions are frequently encountered by radiologists in everyday clinical practice, and are often challenging to evaluate because of the wide range of connective tissue subtypes from which they may arise, resulting in variable imaging appearances. On rare occasions, they may also be associated with bone lesions, which can cause further diagnostic confusion. Synchronous lesions represent a major diagnostic and therapeutic challenge in clinical practice, as they may include both benign and malignant entities. An overview of the different imaging features and an appropriate diagnostic algorithm may lead to a more specific diagnosis, which is essential for effective clinical management. The identification of certain imaging features may help differentiate malignant from benign lesions and therefore influence patient treatment and prognosis.
OBJECTIVES:To evaluate the accuracy of the Cadmium-Zinc-Telluride (CZT) D-SPECT (Spectrum Dynamics, Israel) system in quantifying left ventricle (LV) perfusion and function in 99mTc myocardial perfusion imaging (MPI) at half count statistics. METHODS:Segmental perfusion, extent and volume of a perfusion defect were evaluated in an anthropomorphic phantom simulating normal and pathological myocardial condition at the reference 1 million counts (Mc) and at reduced count statistics (0.8, 0.6, 0.4, 0.25Mc).Summed Stress Scores (SSS), Summed Rest Scores (SRS), Summed Difference Score (SDS), Total Perfusion Deficit (TPD), Ischemic Total Perfusion Deficit (ITPD) and Ejection Fraction were evaluated in 326 MPI patient studies, stratified on the classification of myocardial perfusion and LV ejection fraction (LVEF), at 1 and 0.5Mc statistics. RESULTS:In the phantom study, the count statistics did not affect mean perfusion and perfusion defect extent and volume down to 0.4Mc.In the patient study, high concordance was observed between datasets, with Kw values of 0.846 (SSS), 0.922 (SRS), 0.676 (SDS), and K values of 0.89 (TPD) and 0.70 (ITPD). Bland Altman analysis showed minimal bias and narrow limits of agreement for LVEF (-0.1%; -6.9% to 6.7%). CONCLUSIONS:The study demonstrated the feasibility of a 50% count reduction for myocardial perfusion imaging performed with the D-SPECT system and the acquisition/reconstruction protocol evaluated in this study, preserving diagnostic accuracy while lowering radiation exposure or acquisition time. ADVANCES IN KNOWLEDGE:The ability to maintain diagnostic accuracy with 50% fewer counts supports the adoption of optimized, low-dose SPECT protocols enhancing patient safety and imaging efficiency. This reinforces the role of CZT technology in low-dose nuclear cardiology.
OBJECTIVE:To develop a multimodal model for predicting ground-glass nodule (GGNs) invasiveness, enabling accurate differentiation of pre-invasive lesions (PIL), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IA). METHODS:The retrospective study included pathologically confirmed GGNs between May 2018 and May 2025. Univariate and multivariate logistic regression analysis were performed to screen for independent predictive factors. Semi-automated segmentation of intratumoral region (ITR) and two peritumoral regions (PTRs) scaling strategies were used. Radiomics features from ITR and PTRs were selected via Least Absolute Shrinkage and Selection Operator (LASSO), and random forest (RF), support vector machine (SVM), and logistic regression (LR) models were constructed. Four progressive integration models were further created: Conventional, Conventional + follow-up, Conventional + follow-up + ITR, and Conventional + follow-up + ITR + PTR. RESULTS:517 GGNs were included in the training and internal test cohorts, and 91 GGNs from the external test cohort. Maximum diameter, follow-up composite parameter, vacuole, and air bronchus sign were identified as independent predictive factors. Both PTR construction strategies yielded optimal models (PTR3/ PTR6 for fixed-size, PTR50%/ PTR75% for diameter-ratio). The RF exhibited the highest stability. As feature dimensions expanded from conventional features to follow-up information, ITR, and PTR, the AUC exhibited a progressive increase. The full multimodal model with highest AUCs of 0.849 (training cohort), 0.795 (internal test cohort), and 0.838 (external test cohort). CONCLUSION:The proposed multimodal predictive triple-classification model, integrating conventional, follow-up, ITR, and PTR, may act as a non-invasive tool for preoperative evaluation of GGNs invasiveness. ADVANCES IN KNOWLEDGE:The study first investigated PTR model via the tumor diameter - ratio method and compare it with the fixed-size method. A follow-up composite parameter (Follow-up duration × Follow-up changes status) was used to quantified GGN dynamic changes. The novel multimodal model, integrating conventional, follow-up, ITR, and PTR radiomics features, outperformed single-modal approaches in differentiating PIL, MIA, and IA.
OBJECTIVES:To compare four commercial cone-beam CT (CBCT) geometric quality assurance phantoms within a common workflow, focusing on positioning/repositioning accuracy and agreement between the laser-defined setup reference and the CBCT imaging isocentre. METHODS:MIMI™, QUASAR™ Penta-Guide, ISOCube, and MZ CUBE were evaluated monthly for five months on a Versa HD system with XVI CBCT and a HexaPOD couch. Two observers independently completed each measurement. Three-dimensional post-correction translational residuals (Δdpos/rep) and laser-defined setup reference-CBCT imaging isocentre distances (Δdiso) were calculated. Phantom comparisons used observer-averaged values from the five monthly sessions. Rotational correction and CBCT image quality were assessed descriptively with MZ CUBE. RESULTS:Mean Δdpos/rep values ranged from 0.19 to 0.31 mm, with mean absolute observer differences of 0.05-0.12 mm. No overall difference was found among the four phantoms (p = 0.547). Mean Δdiso values ranged from 0.68 to 0.87 mm, and all measurements were below 2 mm. An overall difference was observed for Δdiso (p = 0.019), although no pairwise comparisons were performed. With MZ CUBE, mean post-correction translational and rotational residuals were 0.24 mm and 0.37°, respectively, and image-quality measures showed no consistent temporal trend. CONCLUSIONS:The four phantoms showed similarly small post-correction translational residuals. In our setting, MZ CUBE additionally supported rotational and image-quality checks. ADVANCES IN KNOWLEDGE:Direct comparison within a common workflow showed similar translational performance, while the scope of additional testing depended on the phantom configuration and locally available accessories.
OBJECTIVE:This study aimed to evaluate coronary inflammation using the perivascular fat attenuation index (FAI) derived from coronary computed tomography angiography (CCTA) in patients with hypertrophic cardiomyopathy (HCM) and to investigate its association with heart failure (HF). METHODS:This retrospective study included 75 patients with HCM and 75 age- and sex-matched controls without structural heart disease. Perivascular FAI was measured around the proximal right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX). All patients underwent cardiac magnetic resonance imaging for comprehensive assessment of left ventricular (LV) morphology, function, and strain parameters. RESULTS:FAI values were significantly elevated in HCM patients compared to controls across all three vessels: LAD-FAI (-75.49 ± 9.04 vs. -83.25 ± 8.97 HU), LCX-FAI (-71.96 ± 9.62 vs. -79.48 ± 8.51 HU), and RCA-FAI (-77.57 ± 10.25 vs. -83.20 ± 8.98 HU); all p < 0.001. LAD-FAI demonstrated modest but significant correlations with markers of adverse LV remodeling, including LV mass index and global strain parameters. On multivariable logistic regression analysis, LAD-FAI was independently associated with HF (OR: 1.40; 95% CI: 1.12-1.99; p = 0.018). CONCLUSION:Coronary inflammation, quantified by perivascular FAI on CCTA, is significantly heightened in patients with HCM and is correlated with LV hypertrophy and dysfunction. Notably, increased LAD-FAI is independently associated with heart failure after adjustment for the included CMR parameters, suggesting its potential utility as a non-invasive imaging biomarker for risk stratification in HCM, pending external validation. ADVANCES IN KNOWLEDGE:This study provides initial evidence that perivascular FAI, a non-invasive imaging marker of coronary inflammation, is significantly elevated in patients with HCM and correlates with adverse left ventricular remodeling, impaired myocardial strain, and elevated NT-proBNP levels. Notably, increased LAD-FAI was independently associated with heart failure, suggesting a mechanistic link between regional coronary inflammation and disease severity in HCM. These findings highlight the potential utility of perivascular FAI as an imaging biomarker for heart failure risk stratification in HCM, warranting further validation in larger, prospective multicenter cohorts.
PURPOSE:In radiotherapy for bleeding gastric cancer, no standard response definition exists; studies have used transfusion-only or transfusion-plus-hemoglobin criteria. After inter-facility transfer or during home care-sometimes following palliative radiotherapy-laboratory results from other facilities are often unavailable, leaving patients inevaluable. We therefore tested whether omitting hemoglobin compromises the precision of response assessment. METHODS AND MATERIALS:In criteria A, referring to our original study, patients were diagnosed as responders when all the following three conditions were met: (1) hemoglobin levels ≥ 8.0 g/dL; (2) 14 consecutive days without blood transfusion before blood sampling; and (3) no salvage treatment. In criteria B, patients were diagnosed as responders when only (2) and (3) of the above conditions were met. The strength of agreement between criteria A and B was estimated by calculating Gwet's first-order agreement coefficient (AC1) at 4- and 8-week follow-up for patients completing planned radiotherapy with assessable response. RESULTS:In 36 evaluable patients at 4-week follow-up, response rates were 69% (25/36) by criteria A vs. 78% (28/36) by criteria B (AC1, 0.86; almost perfect agreement). In 30 evaluable patients at 8-week follow-up, response rates were 83% (25/30) by criteria A vs. 90% (27/30) by criteria B (AC1, 0.91; almost perfect agreement). CONCLUSIONS:Criteria A and B showed almost perfect agreement at 4- and 8-week assessments among evaluable patients with available hemoglobin data. ADVANCES IN KNOWLEDGE:Among patients with available hemoglobin data, criteria A and B showed almost perfect agreement. The observed agreement may not be fully generalizable to patients without hemoglobin assessment.
OBJECTIVES:To determine the most repeatable anatomical plane for placental segmentation and investigate any correlation between gestational age (GA) and texture and shape features of healthy placenta, placenta previa (PP) and placenta accreta spectrum (PAS). METHODS:T2 MRIs from 190 women with PP, PAS and healthy placenta were collected from a single centre. Intra- and inter-observer studies were conducted by three operators, each manually segmenting three times in the sagittal, coronal, and axial planes. 2525 texture and shape features were extracted from each MRI using PyRadiomics, and their correlation with GA determined using Spearman's correlation coefficient (ρ). RESULTS:For the segmentation study, three healthy and three PAS pregnancies were investigated. The sagittal plane exhibited the highest median dice coefficient (DC) in the intra-observer study for PAS (0.915) and inter-observer study for healthy (0.907) and PAS (0.891).For correlation with GA, 46 healthy, 49 PAS and 57 PP MRIs were utilized. Texture features like grey level non-uniformity exhibited strong correlations with GA in the healthy group (ρ=0.81, p < 0.001), but only moderate correlations in the PP (ρ=0.58, p < 0.001) and PAS (ρ=0.52, p < 0.001) groups. CONCLUSION:The sagittal plane was the most repeatable anatomical plane for manually segmenting healthy placenta and PAS. Texture features describing heterogeneity were correlated with GA, particularly in healthy placenta. ADVANCES IN KNOWLEDGE:Texture and shape features captured the increase in heterogeneity seen throughout gestation on placental MRI, indicating a need to consider GA when investigating textural differences in healthy placentas, PP and PAS.
OBJECTIVES:To evaluate the feasibility and generalizability of an AI-based automated method for measuring the pericoronary fat attenuation index (FAI)-a promising non-invasive imaging biomarker for coronary inflammation-and to promote efficient clinical translation. METHODS:A retrospective analysis was conducted on coronary computed tomography angiography data from 1,125 patients (584 [51.9%] male; mean age 61.5 ± 12.3 years; totaling 3,375 coronary arteries) examined using five mainstream CT scanners from different manufacturers, models, and generations. FAI values around the major coronary arteries were quantitatively evaluated using both AI software and workstation. Agreement between methods, diagnostic performance, and scanner influence were assessed. RESULTS:Artificial intelligence-based fat attenuation index (AI-FAI) demonstrated a favorable correlation with workstation-FAI at the patient level (ρ = 0.877, p < 0.001; n = 1,125), along with a high level of agreement (mean bias: 1.60 HU; 95% limits of agreement: -4.94 to 8.14; 94.84% within limits). Using a threshold of -70.1 HU, AI-FAI demonstrated performance comparable to workstation-FAI, with accuracy (84.98%) and solid diagnostic performance (AUC = 0.851). Furthermore, AI-FAI exhibited stable measurement performance across all five scanners, with inter-scanner ρ ranging from 0.829 to 0.896 and only 3.70-6.06% of outliers beyond the agreement limits. CONCLUSIONS:AI-FAI demonstrates favorable agreement with traditional workstation-FAI, solid diagnostic performance, and consistent cross-scanner robustness, providing a reliable automated tool for cardiovascular risk assessment. ADVANCES IN KNOWLEDGE:This is a novel study demonstrating AI-FAI as a practical alternative to workstation-FAI across multiple CT scanners, facilitating reliable quantification of coronary inflammation for routine clinical practice.
OBJECTIVES:A multitude of differing clinical practice exists for prostate radiotherapy, this includes dose prescription, planning methods, asymmetric margins and the presence, or not, of fiducial markers. Institute specific CTV to PTV margins expansion is desirable for optimum treatment of patients. Margins can be determined by assessing geometric errors inherent in radiotherapy. METHODS:The institutional CTV to PTV margins for fiducial free prostate treatments are calculated based on the BIR 2020 methodology derived from the van Herk formulism. Systematic (Σ_tot) and random (σ_tot) errors including delineation, matching and technical accuracy were measured locally while rotational, deformation and intra-fraction errors were quantified from the literature.Σtot and σtot and the penumbral width (σp) are combined with statistical parameters (α) and (β) to calculate the institutional CTV to PTV margin expansion (M) for prostate treatments. RESULTS:An anisotropic CTV to PTV margin expansion for prostate EBRT was calculated. The resulting CTV to PTV margin was 4 mm left/right, 7.5 mm superior, 7 mm inferior, 6 mm anterior and 5.5 mm posterior, rounded to the nearest 0.5 mm. CONCLUSIONS:Systematic errors contributed substantially to the overall margin particularly due to the magnitude of delineation errors. The margin calculated was smaller than the previously set institutional margin and ensures coverage of the PTV by the 95% isodose for 90% of prostate treatments at our centre. ADVANCES IN KNOWLEDGE:Institute specific margins for prostate radiotherapy on a linear accelerator are provided. These are calculated using the BIR 2020 methodology of CTV-PTV margin calculation.
OBJECTIVES:To compare the diagnostic performance of ¹⁸F-FDG PET/CT and ⁶⁸Ga-FAPI PET/CT in patients with gastric cancer, with particular emphasis on metastatic detection and stage migration. METHODS:Fifty-two patients with histopathologically confirmed gastric cancer who underwent both ¹⁸F-FDG PET/CT and ⁶⁸Ga-FAPI PET/CT were retrospectively analyzed. Primary tumor uptake, metastatic involvement, and tumor staging were evaluated for each modality. Detection rates for lymph node, peritoneal, liver, and bone metastases were compared. Diagnostic performance and stage migration between modalities were assessed. Quantitative parameters including SUVmax and tumor-to-background ratio were analyzed. RESULTS:⁶⁸Ga-FAPI PET/CT demonstrated significantly higher uptake in primary tumors compared with ¹⁸F-FDG PET/CT (p < 0.001). Peritoneal metastases were detected in 30.8% (16/52) of patients on ⁶⁸Ga-FAPI PET/CT compared with 13.5% (7/52) on ¹⁸F-FDG PET/CT (p = 0.004). Nodal metastases were also identified more frequently with ⁶⁸Ga-FAPI PET/CT. Both modalities showed high diagnostic performance for liver metastases, while ⁶⁸Ga-FAPI PET/CT demonstrated slightly higher sensitivity for bone lesions and ¹⁸F-FDG PET/CT showed slightly higher specificity. Overall stage migration between the two modalities occurred in 25.0% (13/52) of patients, predominantly due to upstaging associated with newly detected metastatic disease. In subgroup analysis, ¹⁸F-FDG uptake tended to be lower in signet-ring cell carcinoma, whereas FAPI uptake appeared less influenced by histological subtype. CONCLUSION:⁶⁸Ga-FAPI PET/CT improves detection of metastatic disease, particularly peritoneal involvement, compared with ¹⁸F-FDG PET/CT in patients with gastric cancer and may contribute to more accurate disease staging. ADVANCES IN KNOWLEDGE:This study highlights the added value of 68Ga-FAPI PET/CT in identifying metastatic disease and altering clinical staging, particularly through improved detection of peritoneal involvement, which may impact treatment decision-making.
OBJECTIVES:To evaluate peak uptake value (PUVmax) derived from positron emission mammography (PEM) as a functional biomarker for identifying high-risk/high-proliferation phenotypes and addressing biopsy sampling limitations in malignant non-mass enhancement (NME). METHODS:This prospective study included patients with MRI-detected BI-RADS 4-5 NME between March 2023 and March 2025. Of 246 patients assessed, 92 were excluded because of benign pathology, planned neoadjuvant therapy, incomplete histopathological data, or unavailable surgical outcomes, leaving 154 patients with histologically confirmed malignancy and surgical pathology. All underwent ultrasound-guided core-needle biopsy followed by surgical excision. PEM was performed before biopsy (n = 91) or at least 2 weeks afterward (n = 63). PUVmax was measured, with ≥4.1 defining a high-risk biological phenotype. Interobserver agreement was assessed using the intraclass correlation coefficient (ICC). ROC, multivariable logistic regression, and reclassification analyses were performed. RESULTS:Interobserver agreement was excellent (ICC=0.94). Biopsy-surgical discordance occurred in 26/154 cases (16.9%), mainly upgrades (24/26). PEM identified 20/24 upgrades (83.3%). Concordance between PEM and surgical pathology was 97.4%, with four false-negative cases (2.6%) and no false positives. PUVmax was significantly associated with high-risk/high-proliferation phenotype (OR = 2.89, 95% CI: 1.95-4.28; p < 0.001; AUC=0.86). CONCLUSION:PEM-derived PUVmax shows high concordance with surgical pathology and may provide a reliable whole-lesion functional biomarker of high-risk biology in malignant NME. ADVANCES IN KNOWLEDGE:A PUVmax threshold ≥4.1 distinguished low- from high-risk disease across invasive carcinoma and ductal carcinoma in situ. PEM correctly reclassified 84.6% of biopsy-surgical discordant cases, potentially reducing underestimation caused by limited biopsy sampling of biologically heterogeneous lesions.
OBJECTIVES:Ewing sarcoma radiotherapy requires precise target volume delineation. As part of the implementation of the SIOP Inter-Ewing-1 trial in France, we conducted a national benchmark and educational workshop to assess and improve delineation quality among pediatric radiation oncology centers. METHODS:French pediatric radiotherapy centers were invited to participate in a benchmark case of postoperative clavicular Ewing sarcoma. Twelve radiation oncologists submitted initial delineations, and eight participated both before and after an educational workshop. Delineations were evaluated qualitatively using overlap color maps and quantitatively using Dice coefficient (DC), Hausdorff distance (HD), concordance/discordance indices, and volume ratios, relative to an expert-defined reference contour (CRef). RESULTS:Pre-workshop delineations showed substantial heterogeneity, with all DC values <0.7 except for CTVp_Pre, and HD values >20 mm for all target volumes. The most frequent deviation was under-contouring of initial bone involvement, which was the key point of discussions during the workshop. After the workshop, all target volumes increased, reflecting improved inclusion of areas at risk for relapse. Significant improvements were observed for DC in GTVp_Post and CTVp_Post, as well as for concordance indices. However, discordance indices increased for most volumes due to target overestimation, and HD did not significantly improve. CONCLUSIONS:This national benchmark revealed poor delineation homogeneity in postoperative Ewing sarcoma case. The educational workshop provided modest improvements but variability remained substantial. ADVANCES IN KNOWLEDGE:These findings highlight the critical need for prospective radiotherapy quality assurance (RTQA), including prospective individual case review, to enhance compliance with contouring guidelines and ensure high-quality radiotherapy delivery.
OBJECTIVES:To quantify the diagnostic utility of multiphase-CT as a second line imaging modality for parathyroid adenoma localisation including assessing the differences between patients undergoing second line imaging due to negative or discordant first-line imaging (MIBI SPECT/CT) results. METHODS:Patients undergoing multiphase-CT following negative or discordant first-line imaging were collected retrospectively over a 5-year period from 2019-2023. 73 patients were included. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, positive and negative likelihood ratios of multiphase CT for preoperative parathyroid adenoma lateralisation (correct side) and localisation (correct quadrant) were calculated. Results for the whole cohort, negative imaging cohort and discordant imaging cohorts were compared. RESULTS:Fifty-eight of the included patients were female, and 15 were male. Mean age was 56.2 ± 11.8. One-hundred and eighty-three quadrants and 98 sides were explored surgically. 69.8% patients underwent a minimally invasive surgical procedure. Across the whole cohort, multiphase CT demonstrated a sensitivity of 70.4% (95% CI 58-81) and specificity of 86.4% (79-92). For lateralisation, performance was higher with sensitivity 82.6% (72-91) and specificity 86.2% (68-96). Moderate positive likelihood ratios were also recorded as 5.26 (localisation) and 5.99 (lateralisation). CONCLUSIONS:Multiphase CT provided reliable diagnostic accuracy for localisation and lateralisation of parathyroid adenomas in the context of discordant or negative first-line imaging. Its high specificity and moderate positive likelihood ratios make it a valuable rule-in tool that enables targeted surgical approaches. ADVANCES IN KNOWLEDGE:This study provides one of the largest datasets in the literature. Positive results suggest that CT can be considered in cases of negative or discordant first-line imaging if minimally invasive surgical techniques are desired.
OBJECTIVES:This systematic review describes the spectrum, distribution, and etiologies of non‑target [68Ga]Ga‑DOTANOC‑avid lesions proven by histopathology or follow‑up to be unrelated to normal biodistribution or the primary SSTR‑expressing disease. METHODS:PubMed, Web of Science, and Scopus databases were utilized to conduct a systematic search and were updated until May 31, 2025. Three authors independently screened the titles and abstracts of the retrieved articles and selected the articles on the basis of the inclusion and exclusion criteria. RESULTS:Seventy-six eligible studies encompassing 542 patients reported 799 non-target [68Ga]Ga-DOTANOC-avid findings. Nononcologic causes accounted for the majority (59.6%), with malignant oncologic and benign tumorous etiologies accounting for 30.2% and 10.3%, respectively. The abdomen was the most common anatomical site (38%), followed by the thorax (21.6%), head/neck (18.1%), and musculoskeletal system (13.1%), whereas pelvic involvement was least common (9%). CONCLUSIONS:Abdominal non-target [68Ga]Ga-DOTANOC-avid findings represent a major interpretive challenge in [68Ga]Ga-DOTANOC PET/CT, as these findings often overlap with NET-predominant regions. Recognition of these patterns can increase diagnostic accuracy and support broader clinical integration of [68Ga]Ga-DOTANOC beyond its conventional utility.
Vascular cognitive impairment and dementia (VCID) is a leading modifiable contributor to dementia, accounting for an estimated 27-33% of attributable dementia cases. Neuroimaging is central to detection, phenotyping, and longitudinal monitoring. This neuroradiology-focused review integrates the STRIVE-2 imaging lexicon with the VasCog-2 clinical framework and reviews the advanced MRI techniques most pertinent to VCID, spanning clinically established to emerging research approaches: arterial spin labelling, diffusion tensor imaging including peak width of skeletonised mean diffusivity (PSMD), quantitative susceptibility mapping, vessel architecture imaging, and resting-state functional MRI. Unlike previous reviews, we consolidate operational quantitative thresholds already informing decisions (the Staals total small-vessel-disease score, longitudinal white matter hyperintensity progression linked to dementia risk, microbleed and cortical superficial siderosis (cSS) criteria for anti-amyloid therapy eligibility, and validated PSMD reference ranges) and we critically address gaps between research-grade acquisitions and routine clinical workflows. Automated segmentation and structured reporting are transitioning into deployment, expanding the radiologist's role to combine pattern recognition with quantitative characterisation. We outline current limitations of standardisation, reproducibility, and external validation that remain prerequisites before quantitative VCID imaging achieves formal regulatory biomarker qualification.
OBJECTIVES:To develop a multi-task learning (MTL) framework for the simultaneous segmentation of spontaneous intracerebral hemorrhage (sICH) and perihematomal edema (PHE), along with the prediction of hematoma expansion (HE). METHODS:This multicenter retrospective study collected baseline non-contrast CT (NCCT) images of 981 patients with sICH from four centers, with 429 cases for training, 183 cases for internal validation, and 369 cases for external testing. A multi-task sICH model (MTsICHM) was designed to simultaneously segment hematoma and PHE and predict HE, which employs a hard parameter-sharing architecture based on a 3D U-Net backbone. The model processes dual-window NCCT inputs and generates three outputs: a binary hematoma mask, a binary PHE mask, and a binary HE label. For comparative evaluation and ablation studies, four control models were constructed: a multi-task segmentation comparative model, a multi-task classification comparative model, a single-task segmentation comparative model, and a single-task classification comparative model. RESULTS:For hematoma segmentation, MTsICHM achieved mean Dice of 0.909 and Intersection over Union of 0.872; for PHE segmentation, it attained 0.686 and 0.644, respectively, consistently outperforming the comparative models. For HE prediction, it yielded an AUC of 0.888, with corresponding accuracy, sensitivity, and specificity of 0.765, 0.949, and 0.710. CONCLUSIONS:The MTsICHM accurately segments hematoma and PHE while effectively predicting HE, demonstrating substantial potential for clinical application. ADVANCES IN KNOWLEDGE:MTsICHM simultaneously quantifies hematoma and PHE and predicts HE from a single NCCT, with high consistency to manual segmentation and clinical utility for risk identification.
OBJECTIVES:To evaluate fractal dimension (FD) as a quantitative prostate cancer (PCa) biomarker for the International Society of Urological Pathology Grade Group (ISUP-GG) and validate its diagnostic accuracy using clinical data from multi-scanner sources. METHODS:Over a 20-month period, 153 men with biopsy-proven PCa aged 48.6-83 years (mean 67.0±7.1 years; ISUP-GG 1-5 distribution: n = 2, 68, 44, 21 and 18), imaged on multiple scanners with differing fat-saturation protocols, had FD retrospectively calculated from the edge of the index lesion. Signal Intensities (SI) on dynamic contrast-enhanced magnetic resonance images (DCE-MRI) were normalised to the obturator internus muscle. For reproducibility, 20 patients had repeat FD extracted by an independent observer. FD was correlated with ISUP-GG. Previously determined thresholds were applied to determine diagnostic accuracy of FD for separating ISUP-GGs. RESULTS:After image normalisation, tumour SI values showed similar distributions between scanners. There was a significant correlation between FD and ISUP-GG (R = 0.87, p < 0.000001). A pre-specified threshold from previous datasets of 2.31 separated ISUP-GG1-2 from 3-5 with 95.2% sensitivity, 92.9% specificity and 94.1% diagnostic accuracy. In 20 randomly selected cases, mean inter-reader FD difference was -0.01, Bland-Altman limits of agreement -0.08 to + 0.05. CONCLUSIONS:FD is an accurate biomarker for grading PCa using standard clinical DCE-MRI with differing fat-saturation schemes that affect SI. ADVANCES IN KNOWLEDGE:Fractal dimension of DCE-MRI allows for non-invasive stratification of PCa and generalises to different MRI scanners and fat-saturation protocols.
This study provides a review of recent publications on different quality control (QC) techniques for radiotherapy linear accelerators (linacs). QC in radiotherapy is essential to ensure patient safety, deliver optimal quality treatments, monitor equipment performance over time and to satisfy statutory or recommended testing. Whilst conventional QC methods are still widely used and valuable, there have been advances in QC methods and approaches which aim to improve efficiency and keep pace with the rapidly advancing complexity of clinical equipment and treatment delivery methods. Existing reviews of QC concepts mainly focus on single QC techniques. There are limited reviews that explore and compare the variety of techniques to QC, which is the aim of this report. QC techniques were separated into seven domains: conventional QC, automated & manufacturer integrated QC, risk, statistical, artificial intelligence (AI), end-to-end & patient-specific QC (PSQC), external dosimetry audits & clinical trial credentialing audits. An overview of each technique with example studies from literature is presented.
