PURPOSE:Accurate delineation of the prostate and surrounding pelvic structures is critical to successful treatment planning, accurate identification, and staging of prostate cancer. Segmentation of anatomically complex regions surrounding the prostate in CT imaging can be challenging due to low soft-tissue contrast and complex boundary delineations. In this work, we investigate three complementary paradigms of knowledge distillation-voxel-level, region-level, and a dynamically weighted combination of the two-to improve segmentation performance for the prostate and parailiac regions. METHODS:The region-level approach imposes the semantic coherence of network predictions via the region-wise contrastive form of supervision, whereas the voxel-level distillation provides fine-tuned supervision in terms of Kullback-Leibler divergence on soft probabilistic outputs. We introduce a novel fusion approach that adds uncertainty-aware dynamic weighting, thus allowing the model to adjust the contribution of every distillation loss in an adaptive manner during training, taking advantage of the strengths of both approaches. The distillation methods are implemented within the dual-network architecture in terms of VNet (Milletari et al. in Proc. Int. Conf. 3D Vis. (3DV):565-571, 2016) and 3D-ResVNet (Wang et al. in Proc. IEEE/CVF Conf. Comput. Vis. Pattern Recognit. (CVPR)), thus allowing synergistic learning of different architectural biases. RESULTS:Experimental results on both an in-house collected and annotated CT dataset of prostate cancer patients-where parailiac regions and the prostate gland (including seminal vesicles) are manually segmented-and three public benchmark datasets demonstrate that each individual distillation method consistently improves segmentation accuracy over baseline models. These results indicate that the effectiveness of the proposed distillation strategies generalizes across different datasets and anatomical structures, highlighting their robustness and practical applicability. CONCLUSION:Complementary supervision at voxel and region levels can improve the delineation of complex pelvic structures in CT imaging of prostate cancer.

PURPOSE:To evaluate the role of 68Ga-FAPI PET/CT in primary staging of breast cancer in comparison with 18F-FDG PET/CT. METHODS:In this prospective study, 50 breast cancer patients (49F,1M, age:54.56 ± 13.73) were included. 18F-FDG PET/CT and 68Ga-FAPI PET/CT were performed consecutively for staging purposes. Patient-based sensitivity, specificity, PPV, NPV and accuracy were calculated. Relationship between semiquantitative 68Ga-FAPI PET parameters and histopathology were analysed. RESULTS:Patient based sensitivity for detection of primary breast lesions of 68Ga-FAPI were higher than 18F-FDG PET/CT (100 % (95 % CI: 92.9-100.0) vs 92 % (95 % CI: 80.4-100)), although not reached statistical significance (exact McNemar p = 0.0625). PPV was 100 % (95 % CI: 92.9-100.0) for both modalities. For lymph node metastases, patient-based sensitivity, specificity, PPV, NPV and accuracy of 68 Ga-FAPI PET/CT were 72.4 % (95 % CI: 52.8-87.3), 95.2 % (95 % CI: 76.2-99.9), 95.5 % (95 % CI: 77.2-99.9), 71.4 % (95 % CI: 51.3-86.8) and 82.0 % (95 % CI: 68.6-91.4), respectively, whereas those of 18F-FDG PET/CT were 60.7 % (95 % CI: 40.6-78.5), 85.7 % (95 % CI: 63.7-97.0), 85.0 % (95 % CI: 62.1-96.8), 62.1 % (95 % CI: 42.3-79.3) and 71.4 % (95 % CI: 56.7-83.4), respectively (for sensitivity and specificity, exact McNemar p = 0.125 and p = 0.50). Mean SUVmax of 68Ga FAPI uptake of primary breast lesions were significantly higher than 18F-FDG uptake (13.32 ± 7.1 vs 6.86 ± 3.51p < 0.001). Ki-67 of the primary tumors was correlated with SUVmean and TLU of axillary lymph nodes (r = 0.64,p = 0.006 and r = 0.66,p = 0.004). PR positivity and TV of the breast lesions were inversely correlated (r = -0.32,p = 0.044). There were 4 patients with distant metastasis: skeletal metastases in 3 patients and liver metastasis in one patient. 68Ga-FAPI showed greater number of skeletal metastasis in 1 patient and revealed an 18F-FDG negative liver metastasis in another patient. 68Ga-FAPI PET/CT changed management in 6 patients (12 %). Exploratory subgroup analyses demonstrated that 68Ga-FAPI PET/CT maintained a 100 % detection rate across all evaluated biological subgroups, whereas the detectability of 18F-FDG PET/CT varied according to tumor biology, with the lowest detection rate observed in Grade 1 tumors; paired subgroup comparisons using the exact McNemar test did not demonstrate statistically significant differences in detectability rates, although 68Ga-FAPI PET/CT showed significantly higher SUVmax values in several biological subgroups, particularly in hormone receptor-positive and Grade 1 tumors. CONCLUSION:68Ga-FAPI PET/CT demonstrated promising diagnostic performance for the detection of primary breast tumors, lymph node metastases, and selected distant metastatic lesions. Although paired statistical analysis did not demonstrate significant differences compared with 18F-FDG PET/CT, 68Ga-FAPI PET/CT provided additional clinically relevant findings in a subset of patients. Larger multicenter studies are needed to further define its clinical role in breast cancer staging.

To evaluate the prognostic utility of a novel quantitative imaging metric, whole-body metabolic burden (WB-MB), derived from [11C]-Methionine PET/CT, in patients with multiple myeloma (MM), and to assess its correlation with clinical biomarkers and survival outcomes. In this prospective, single-center study, 34 patients with biopsy-confirmed MM underwent whole-body [11C]-Methionine PET/CT for staging or restaging. WB-MB was calculated using a semi-quantitative method incorporating both the extent and intensity of methionine uptake across 12 anatomical regions. Liver- and aorta-normalized WB-MB ratios (WB-MB/liver and WB-MB/aorta) were also computed. Correlations with laboratory biomarkers were analyzed using regression models, and prognostic performance was assessed through Kaplan-Meier survival analysis and hazard ratios for progression-free survival (PFS) and overall survival (OS). WB-MB showed significant inverse correlation with hemoglobin and positive correlations with LDH, beta-2 microglobulin (B2M), and serum kappa free light chain levels. No significant associations were observed with platelet count, WBC, or lambda light chains. WB-MB, WB-MB/liver, and WB-MB/aorta were all significantly associated with OS and PFS (p < 0.05), while maximum SUVmean was not. A WB-MB threshold of 164.79 was identified as predictive for PFS. Notably, no deaths occurred in patients with WB-MB < 101 during follow-up. WB-MB scoring with [11C]-Methionine PET/CT is a promising, reproducible imaging biomarker for evaluating disease burden and prognosis in MM. It correlates with key laboratory markers and outperforms static SUV-based metrics in predicting survival outcomes. Further multicenter studies are needed to validate these findings and explore integration into therapeutic decision-making.

Importance:In recent decades, there has been marked worldwide growth in diagnostic testing for coronary artery disease (CAD), with several common imaging modalities exposing patients to ionizing radiation. Objective:To examine worldwide radiation doses for patients undergoing noninvasive CAD diagnostic testing. Design, Setting, and Participants:This worldwide, cross-sectional study was conducted of radiation dose from noninvasive CAD imaging in 2023, using a consecutive sample of all 19 302 adults undergoing noninvasive CAD diagnostic testing at 742 centers in 101 countries during a single week in October to December 2023. Exposures:Participants underwent CAD testing with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) nuclear cardiac imaging, cardiac computed tomography for coronary artery calcium scoring (CACS), or coronary computed tomography angiography (CCTA). Main Outcomes and Measures:The primary outcomes were radiation effective dose to patients and the percentage of centers with median effective dose less than or equal to 9 mSv, as recommended in guidelines. Results:Of 19 302 patients, 8515 (44%) were females and the median (IQR) age was 63 (54-71) years. Effective dose varied considerably across diagnostic modalities, with median (IQR) effective dose of 1.2 (0.7-2.2) mSv for CACS, 2.0 (1.6-2.4) mSv for PET, 6.5 (3.9-8.6) mSv for SPECT, and 7.4 (3.5-15.5) mSv for CCTA. Significantly more centers performing nuclear cardiology than CCTA (81% vs 56%; P < .001) and patients undergoing nuclear cardiology studies than CCTA (79% vs 56%; P < .001) achieved median dose of less than or equal to 9 mSv. Doses for the same procedure differed significantly between world regions, being lowest in Western Europe (median [IQR], 4.8 [2.3-7.3] mSv for nuclear cardiology and 4.6 [2.4-9.8] mSv for CCTA) and highest in Latin America for nuclear cardiology (median [IQR], 7.8 [5.3-9.7] mSv) and Africa (median [IQR], 25.2 [14.7-35.3] mSv) for CCTA (P < .001 for all). In regression modeling, there was an inverse relationship between country income level and dose. Patient dose was 20% (95% CI, 3.6%-38.4%) higher in low- and middle-income countries than in high-income countries for nuclear cardiology, and as much as 96% (95% CI, 41.7%-170.8%) higher in low- and lower-middle-income countries than in high-income countries for CCTA (P < .001). Marked variation was observed within income levels and world regions. Conclusions and Relevance:Given increasing rates of CAD worldwide, these findings of marked variation in radiation dose to patients from diagnostic testing identify a critical need for training, standardized protocols, and updated equipment to reduce radiation worldwide. This especially affects patients in low- and middle-income countries and patients undergoing CCTA. There are therefore important opportunities to improve the quality of CAD diagnosis for patients across the globe.

PURPOSE:In this study we aimed to investigate prediction of response with [68Ga]Ga-PSMA PET-derived parameters and the effectiveness of RECIP criteria and PSA response in predicting survival after [177Lu]Lu-PSMA therapy. METHODS:Patients who received at least 2 cycles of [177Lu]Lu-PSMA therapy were retrospectively included in the study. All lesions in the PET images were segmented and PSMA PET-based parameters were extracted. The treatment response was evaluated according to RECIP and PSA criteria. ROC analyses were performed to assess their discriminatory power in predicting response. Correlation of overall survival with RECIP and PSA-based response was evaluated using Kaplan-Meier survival analysis. RESULTS:A total of 41 patients were included in the study. SUVmax, SUVpeak, SUVmean, qPSG-max and qPSG-mean values were significant factors in predicting PSA response. However, in predicting RECIP response (CR + PR), the AUC values for the SUV parameters were not significantly higher than 0.5. In predicting RECIP disease control (CR + PR + SD), the AUC values for SUVmax, SUVpeak, and SUVmean were 0.742(p = 0.002), 0.742(p = 0.002), and 0.722(p = 0.006). In the RECIP-responder and non-responder groups, the median survival was 33.5 and 15.2 months (p = 0.005). In patients with RECIP-disease control and progressive disease, the median survival was 25.1 and 15.2 months (p = 0.002). However, the survival difference between PSA-responder and non-responders groups did not reach significance (p = 0.127). CONCLUSION:PSMA PET imaging is a useful method to select patients who will most likely to benefit from [177Lu]Lu-PSMA treatment. Also, it has been shown that RECIP has significantly performed better than PSA-based response evaluation in terms of predicting overall survival.

68 Ga-FAPI has emerged as an alternative tracer for tumor imaging, as FAP is expressed in >90% of epithelial cancers. Although promising data on this new radiotracer are increasing, false-positive results due to nonmalignant diseases with FAP uptake are also reported (for instance, chronic inflammation, arthritis, and fibrosis). In this case, we demonstrated 68 Ga-FAPI PET/CT involvement in a patient diagnosed with hepatic sarcoidosis.

Objectives The objective of this study is to evaluate the diagnostic performance of neck fluorodeoxyglucose (FDG) PET/MRI in addition to whole-body PET/computed tomography (CT) and to compare it with MRI in the detection of suspicion of disease relapse in patients with differentiated thyroid cancer (DTC) who underwent total thyroidectomy and radioactive iodine therapy. Methods Twenty-nine patients with DTC who underwent whole-body 18F-FDG PET/CT followed by neck PET/MRI because of increased serum thyroglobulin (Tg) or anti-Tg antibody levels and negative 131I whole-body scan were included. At least 6 months of clinical and radiological (neck ultrasound) follow-up or histopathological examination results were accepted as the gold standard. Lesion and compartment-based analyses were performed to evaluate the diagnostic performances of PET/CT, MRI, and PET/MRI. In addition, changes of clinical management were evaluated. Results On lesion-based analysis, for PET/CT, MRI, and PET/MRI: sensitivity: 33.3, 33.3, and 37%; specificity: 90.1, 87.9, and 95.9%; accuracy: 87.5, 85.4, and 93.2 were calculated, respectively. Specificity of PET/MRI was significantly superior to PET/CT and MRI (P of0.001); however, sensitivity of PET/MRI was not significant to PET/CT and MRI (P of0.05). On compartment-based analysis, specificity of PET/MRI and MRI were comparable but significantly superior to PET/CT at levels 1 and 2; however, specificity of PET/CT and PET/MRI were comparable but significantly superior than MRI, especially at levels 3, 4, and 5. Conclusion PET/MRI especially helps in the accurate exclusion of findings that are suspicious on PET/CT and MRI, and has the potential to change the clinical management by identifying uncertain neck findings.

Objective: The aim of this study was to examine how radioactive iodine (RAI) therapy affected the levels of serum endocan and carotid intima media thickness (CIMT) as well as how these changed over time in the group receiving medical treatment. Method: A total of 52 hyperthyroid patients were included in the study, 26 of whom were planned to receive RAI treatment and 26 of whom were followed up with medical treatment. Measurements of CIMT and serum endocan levels were taken before and 3 months after RAI therapy. The group also received medical treatment at the time of their inclusion in the trial and 3 months later. Results: Older age found to be related with higher CIMT value in all patients (p

INTRODUCTION:Advanced-stage lung adenocarcinoma is associated with poor survival, highlighting the need for improved prognostic tools. PET/computed tomography (CT) metrics and mutation profiling may enhance risk stratification when integrated with clinical parameters. METHODS:This retrospective cohort study included 109 advanced-stage lung adenocarcinoma between 2018 and 2023. PET/CT metrics - standardized uptake value (SUV max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) - were assessed for primary tumors and thoracic regions. ECOG performance status and mutation profiles were also recorded. Cox regression analysis was performed to identify independent predictors of overall survival (OS). RESULTS:In univariate analysis, all PET/CT parameters were significantly associated with OS. In multivariate analysis, thoracic MTV emerged as the strongest independent prognostic factor (HR = 2.85, 95% CI: 1.69-4.81, P < 0.001), followed by ECOG ≥2 (HR = 2.31, 95% CI: 1.18-3.72, P = 0.004). Although KRAS mutations were associated with poorer OS in univariate analysis, they did not retain significance in the multivariate model. CONCLUSION:Our findings emphasize the prognostic value of thoracic MTV as a robust, independent biomarker for advanced-stage lung adenocarcinoma. Integrating PET/CT metrics with clinical and molecular data may improve staging accuracy and inform treatment decisions, particularly in settings where mutational status alone is insufficient.

Pozitron emisyon tomografisi (PET) ile miyokart perfüzyon görüntüleme, son yıllarda kullanımı giderek artan bir modalite olarak ortaya çıkmaktadır.Stres ile indüklenmiş miyokardiyal perfüzyon defektlerini göstermek koroner arter hastalarına (KAH) yaklaşımda önemli tanısal ve prognostik bilgiler sağlamaktadır

A 73-year-old woman with known diagnosis of chronic hepatitis B infection referred for 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and magnetic resonance imaging (MRI) after detection of a liver mass with 9 cm diameter in contrast enhanced CT. However, 18F-FDG PET/CT and MRI revealed diffuse infiltrating hepatocellular carcinoma lesions other than previously defined mass. After 9 months of Sorafenib treatment serum alpha feto protein levels dropped from 60,500 ng/mL to 801 ng/mL. Later 18F-FDG PET/MRI was performed for evaluation of response to treatment and revealed marked response to treatment.

INTRODUCTION Staphylococcus aureus bacteremia (SAB) can be complicated with metastatic foci as a result of seeding to any body site. It is very important to detect metastatic infections for determining the appropriate treatment modality and duration. Here, we presented a S. aureus bacteremia patient complicated with multiple paravertebral and psoas abscess diagnosed with 18F-fluorodeoxyglucose-positron emission tomography in combination with computed tomography (FDG PET/CT). CASE PRESENTATION A sixty nine year-old male patient presented to the emergency department with hip pain, fever and septic clinical findings. His temperature was 390C, pulse rate was 110 beats/min, blood pressure was 100/70 mmHg. Methicilline sensitive S. aureus growth was detected on all blood cultures. Ceftriaxone treatment started in the emergency room was discontinued and cefazolin was started. Transthoracic, transesophageal echocardiography and abdominal ultrasonography was normal. FDG PET-CT scan was planned to investigate the etiology of fever and identify any metastatic infectious foci. PET-CT imaging revealed that increased metabolic activity in the paraspinal regions at the level of thoraco-lumbar vertebrae, psoas muscle and pubic symphisis. Further imaging directed at the areas identified on PET-CT confirmed the presence of a broad paravertebral abscess and psoas. These abcsess were partially drained by neurosurgery specialists because of multiple and wide area involvement. The patient's treatment was continued with oral amoxicillin clavulonic asit until resolution of abcesses. CONCLUSION Previous studies had shown that 18F-FDG PET/CT had a positive impact on outcome and the management of SAB. Diagnostic PET-CT imaging plays a crucial role in targeted management and timely intervention for SAB.

Büyük damar vaskülitleri, Takayasu arteriti ve dev hücreli arterit (DHA) olmak üzere iki ana varyantı olan, esas olarak büyük arterleri etkileyen enflamatuvar bir

IntroductionSeveral neuroimaging studies have been conducted to demonstrate the specific structural and functional brain correlations of conversion disorder. Although the findings of neuroimaging studies are not consistent, when evaluated as a whole, they suggest the presence of significant brain abnormalities. The aim of this study is to investigate brain metabolic activity through F-18 fluorodeoxyglucose PET/MRI in order to shed light on the neural correlates of conversion disorder.Methods20 patients diagnosed with conversion disorder were included in the study. Hamilton Depression and Anxiety Rating Scales, Somatosensory Amplification Scale and Somatoform Dissociation Scale were administered. Then, brain F-18 FDG-PET/MRI was performed..ResultsHypermetabolism was found in posterior cingulate R, while glucose metabolisms of other brain regions were observed to be within the normal limits. When compared with the control group, statistically significant differences in z-scores were observed among all brain regions except for parietal superior R and cerebellum. No correlation was observed between the metabolisms of the left ACC and left medial PFC; left ACC and left temporal lateral cortex; cerebellum and left parietal inferior cortex despite the presence of positive correlations between these regions in the opposite hemisphere.DiscussionResults of the study suggest a potential involvement of the DMN which is associated with arousal and self-referential processing as well as regions associated with motor intention and self-agency.

Ürogenital tümörlerde pozitron emisyon tomografi/manyetik rezonans görüntüleme (PET