Nuklearmedizin. Nuclear medicine最新文献

To determine the value of radiomics data extraction from baseline 18F FDG PET/CT in the prediction of tumor-infiltrating lymphocytes (TILs) among patients with primary breast cancer (BC).We retrospectively evaluated 74 patients who underwent baseline 18F FDG PET/CT scans for BC evaluation between October 2020 and April 2022. Radiomics data extraction resulted in a total of 131 radiomic features from primary tumors. TILs status was defined based on histological analyses of surgical specimens and patients were categorized as having low TILs or moderate & high TILs. The relationships between TILs groups and tumor features, patient characteristics and molecular subtypes were examined. Features with a correlation coefficient of less than 0.6 were analyzed by logistic regression to create a predictive model. The diagnostic performance of the model was calculated via receiver operating characteristics (ROC) analysis.Menopausal status, histological grade, nuclear grade, and four radiomics features demonstrated significant differences between the two TILs groups. Multivariable logistic regression revealed that nuclear grade and three radiomics features (Morphological COMShift, GLCM Correlation, and GLSZM Small Zone Emphasis) were independently associated with TIL grouping. The diagnostic performance analysis of the model showed an AUC of 0.864 (95% CI: 0.776-0.953; p < 0.001). The sensitivity, specificity, PPV, NPV and accuracy values of the model were 69.6%, 82.4%, 64%, 85.7% and 78.4%, respectivelyThe pathological TIL scores of BC patients can be predicted by using radiomics feature extraction from baseline 18F FDG PET/CT scans.

In this retrospective study, we evaluated the diagnostic value of [¹⁸F]FDG PET/CT in preoperative assessment of extrahepatic cholangiocarcinoma (ECC) and to develop a PET-based diagnostic algorithm for ECC.Patients with suspected ECC with biliary obstruction were included. Patients received [¹⁸F]FDG PET/CT scan and image analysis. FDG uptake was semi-quantified using the SUV_max of the suspected primary tumor, lymph nodes and metastatic lesions. Sex, age, tumor location, enhancement patterns and tumor size were analyzed using binary logistic regression for prediction of ECC on PET images.The study included 238 ECC patients and 42 patients with benign diseases. The lesion was located in the common bile duct in 67.50% patients and in the hilar region in 31.79% patients. [¹⁸F]FDG PET/CT scan showed a sensitivity of 70.6% and a specificity of 76.2% for the diagnosis of cholangiocarcinoma in patients with extrahepatic lesions, with a positive predictive value of 94.4% and a negative predictive value of 31.4% and an accuracy of 71.4%. Forced entry logistic regression analysis showed that age (OR 1.07, 95%CI, 1.03 to 1.10) and detection of ECC by [¹⁸F]FDG PET/CT scan (OR 6.15, 95% CI, 2.00 to 19.10) were predictors of ECC. A PET-based scoring algorithm had an AUC of 0.81 (95% CI, 0.75 to 0.88) and had a sensitivity of 61.3% and a specificity of 88.1% for ECC. The algorithm had a significantly better diagnostic performance than [¹⁸F]FDG PET/CT scan (Chi square test, P <0.001).The PET-based algorithm shows improved diagnostic performance for the detection of ECC and could facilitate early diagnosis and staging of ECC.

In patients with primary hyperparathyroidism (pHPT), the importance of oxyphil cells for ^99mTc-sestamibi uptake is uncertain.This retrospective observational study of pHPT patients evaluated independent associations between oxyphil cell content (OCC) and preoperative scintigraphic (SC) findings, using logistic regression analyses.We studied 76 patients with pHPT before and after operation. Preoperative SC was able to definitively identify abnormal parathyroid tissue in 47 patients (61.8%). The median relative OCC (postoperative histopathological examination) was 10% (IQR 0.25% - 40%) and the median absolute OCC was 0.09 cm³ (IQR 0.00 - 0.59 cm³). After adjustment for confounders, an iPTH concentration >200 pg/ml and increasing OCC was the only significant independent predictor of a definitively positive SC result (per category of relative OCC: adjusted odds ratio (aOR) 2.40, 95% confidence interval (CI) 1.02 - 5.65, p=0.045).In patients with pHPT, a higher OCC was associated with a significantly higher probability of a clearly positive SC finding.

Quantifying small tumors is still a challenge due to the partial volume effect (PVE). Although iterative reconstruction had promising results with a better recovery coefficient (RC), it suffers from the PVE. RC values typically depend on the reconstruction method, which may affect on ¹⁷⁷Lu quantifying. In this study, we investigated the effect of different reconstruction methods on RC values for ¹⁷⁷Lu SPECT/CT images.A water-filled cylindrical polymethylmethacrylate (PMMA) phantom without background radioactivity with two solid cylinders which represent the bone and soft tissue equivalent was used for SPECT/CT imaging. We placed syringes with different volumes containing ¹⁷⁷Lu in the vicinity of the cylinders as tumors. The iterative reconstructions of xSPECT, xSPECT Bone, and Flash3D was performed on SPECT/CT images.The effect of the reconstruction algorithms on the RC values was determined by calculating the radioactivity concentration in volumes of interest which were drawn manually and by a threshold method.The xSPECT Bone reconstruction has shown an RC value of approximately 100%, while the other reconstructions typically show an RC value of 93%. The RC values for all the reconstructions were decreased for smaller tumors. The smallest tumor showed a minimum RC between 52% and 72% compared to the largest tumor.In this study, it was possible to obtain an RC value close to 100% when the xSPECT Bone reconstruction algorithm was used. The xSPECT results were slightly lower RC values compared to the Flash3D algorithm. In using standard RC curves for tumors close to the bone, special care has to be taken since RC values relative to bone are higher than in tissue.

A 65-year-old man, who denied a smoking history, presented with chest distress and pain persisting for over a week. A contrast-enhanced chest CT scan revealed a large irregular mass in the right thoracic cavity with heterogeneous enhancement. The 18F-FDG PET/CT showed a large mass in the right thoracic cavity with heterogeneous markedly high FDG uptake. The patient subsequently underwent a bronchoscopic-guided mucosal biopsy at the opening of the right upper lobe. The histological and immunohistochemical findings were consistent with thoracic SMARCA4-deficient undifferentiated tumor.