Nuklearmedizin. Nuclear medicine最新文献

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.

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.

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.

Aim: The early diagnosis of atherosclerotic changes to prevent ischemic events represents a clinical challenge.Prostate-specific membrane antigen (PSMA) as an established diagnostic in the field of prostate cancer also appears to detect neovascularization and inflammation in other diseases. We hypothesized that it might be also suited for detection of inflammation in atherosclerosis.

Methods: We analyzed data of 78 prostate cancer patients who received a PSMA ligand PET/CT for re-staging. The cardiovascular risk factors (CVRF) of each patient were documented. Target-to-background-ratios (TBR) were calculated from the individual uptake values for three different sections of thoracic aorta [ascending (AA) and descending aorta (AD), aortic arch (AoAC)]. Statistical analyses included a linear regression analysis with the PSMA ligand uptake values of the different arterial segments versus different CVRF as independent variables.

Results: The meanTBRmax was measured highest in the AoAC (1.66 ± 0.33) compared to both other vessel sections (AA: 1.46 ± 0.21, p=0.001; AD: 1.59 ± 0.41, p=0.371). There was a correlation between the PSMA ligand uptake in all measured segments of the aorta and BMI, but only a significant correlation in the ascending aorta (r=0.347, p=0.001). This was confirmed in a subgroup analysis, which showed significantly higher uptake values in preadiposity (BMI >25) and obesity (BMI >30) patients in the ascending aorta (p=0.048).

Conclusion: PSMA ligand uptake in the ascending aorta was linked to BMI. PET detection of vascular PSMA ligand uptake may be indicative of vessel wall inflammation to some extent. However, PSMA ligands appear to be less suitable than other tracers for this purpose, given their absent correlation with most established CVRFs.

Objective: To determine whether [¹⁸F]FDG PET/CT and hematological parameters provide supportive data to determine HPV status in HNSCC patients.

Methods: Retrospective analysis of clinical and diagnostic data from 106 patients with HNSCC: 26.4% HPV-positive and 73.6% HPV-negative was performed. The following semiquantitative PET/CT parameters for the primary tumor and hottest lymph node and liver were evaluated: SUV_max, SUV_mean, TotalSUV, MTV, TLG, maximum, mean and TLG tumor-to-liver ratio (TLR_max, TLR_mean,TLR_TLG) and heterogeneity index (HI). Following hematological variables were assessed: white blood cell (WBC); lymphocyte (LYMPH); neutrophil (NEU),monocyte (MON); platelet (PLT); neutrophil-to-lymphocyte ratio (NRL); lymphocyte-to-monocyte ratio (LMR); platelet-to lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR). Conventional statistical analyses were performed in parallel with an artificial neural network analysis (Neural Analyzer, v. 2.9.5).

Results: Significant between-group differences were observed for two of the semiquantitative PET/CT parameters, with higher values in the HPV-negative group: primary tumor MTV (22.2 vs 9.65; p=0.023), and TLR_max (3.50 vs 2.46; p=0.05). The HPV-negative group also had a significantly higher NEU count (4.84 vs. 6.04; p=0.04), NEU% (58.2 vs. 66.2; p=0.007), and NRL% (2.69 vs. 3.94; p=0.038). Based on ROC analysis (sensitivity 50%, specificity 80%, AUC 0.5), the following variables were independent predictors of HPV-negativity: primary tumor with SUV_max >10; TotalSUV >2800; MTV >23.5; TLG >180; TLR_max >3.7; TLR_TLG >5.7; and oropharyngeal localization.

Conclusion: Several semiquantitative parameters derived from [¹⁸F]FDG PET/CT imaging of the primary tumor (SUV_max, TotalSUV, MTV, TLG, TLR_max and TLR_TLG) were independent predictors of HPV-negativity.

In this study, standard 2D lung lobe quantification is compared with two 3D lung lobe quantification software tools to investigate the clinical benefit of a 3D approach. The accuracy of 2D versus 3D lung lobe quantification is evaluated based on the calculated numerical ventilation-perfusion ratio (VQR) using a receiver operating curve (ROC) analysis.A study group of 50 consecutive patients underwent a planar lung scintigraphy (anterior/posterior) as well as ventilation/perfusion single photon emission computed tomography (SPECT/CT) to exclude acute pulmonary embolism. All data were acquired with SPECT OPTIMA NM/CT 640 (GE Healthcare). 2D analysis was performed for all ventilation/perfusion scans using a lung analysis tool (Syngo Workstation, Siemens Healthineers). 3D quantification analysis was performed using QLUNG (Q. Lung, Xeleris 4.0, GE Healthcare) and LLQ (Hermes Hybrid 3D Lung Lobar Quantification, Hermes Medical Solutions). The area under the ROC curve (AUC) served as a decision criterion to find the best agreement between clinical PE findings and calculated PE candidates of the 2D and 3D methods. The significance of the ROC curves was evaluated using the DeLong comparison.A significant difference between 2D/3D could be determined. Both 3D approaches showed robust and comparable results. The AUC range of [0.10, 0.67] was given for 2D lobar analysis, QLUNG AUC range revealed in [0.39,0.74] and LLQ AUC range was [0.42,0.72]. Averaged over all lung lobes an AUC=0.39 was given for 2D analysis and AUC=0.58 was given for LLQ/QLUNG.We could demonstrate the better performance of 3D analysis compared to 2D analysis. Consequently, is recommended to use a 3D approach in clinical practice.

Purpose: This study aims to establish a normal range for the thyroid uptake derived from ^99mTc pertechnetate scans. In particular, variations of uptake with TSH stimulation and other factors such as urinary iodine concentration are taken into account and compared with the calculation of a raw uptake value.

Methods: Clinical multicentric (center A, B and C) prospective study on 125 consecutive healthy patients undergoing thyroid scans for thyroid nodules. Normal functional thyroid status was assured by normal TSH, normal thyroid size, no thyroid antibodies and no symptoms of thyroid functional disorders. Calculations of raw Tc-uptake (uptake) and modified uptake values regarding current TSH value (uptake_TSH1), urinary iodine concentration (uptake_TSH1&uic), gland volume, age, smoking status, weight and tissue thickness ventral to the thyroid were performed.

Results: There is a positive correlation of thyroid uptake with TSH allowing for the calculation of a normalized uptake value (uptake_TSH1). The normal range for uptake_TSH1 compares favourable to that for raw uptake in that it yields a clear distinction from thyroid functional disorders. The additional normalization for urinary iodine concentration (uptake_TSH1&uic) may even improve the distinctive power whereas further normalizations such as for gland volume, age and others are not warranted by this study. The 95% CI of uptake_TSH1 for sites A, A&B, and A&B&C were 0.21%-2.06%, 0.22%-2.38% and 0.24%-2.40%.

Conclusion: A normal range for the thyroid uptake can be established with respect to the current TSH stimulation. This normalization (uptake_TSH1) overcomes the drawback of raw uptake by yielding a clinically useful parameter with obviously high distinctive power against functional thyroid disorders.

Selective internal radiotherapy (SIRT) or transarterial radioembolisation (TARE) is an alternative treatment for hepatocellular carcinoma (HCC) or hepatic metastatic colorectal carcinoma (mCRC) and is now anchored in many guidelines. The article summarises the current guidelines on SIRT/TARE in HCC and mCRC.