Nuclear Medicine Communications最新文献

Background: Microvascular infiltration (MVI) before liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) is associated with postoperative tumor recurrence and survival. MVI is mainly assessed by pathological analysis of tissue samples, which is invasive and heterogeneous. PET/computed tomography (PET/CT) with 18 F-labeled fluorodeoxyglucose ( 18 F-FDG) as a tracer has been widely used in the examination of malignant tumors. This study investigated the association between 18 F-FDG PET/CT metabolic parameters and MVI before LT in HCC patients.

Methods: About 124 HCC patients who had 18 F-FDG PET/CT examination before LT were included. The patients' clinicopathological features and 18 F-FDG PET/CT metabolic parameters were recorded. Correlations between clinicopathological features, 18 F-FDG PET/CT metabolic parameters, and MVI were analyzed. ROC curve was used to determine the optimal diagnostic cutoff value, area under the curve (AUC), sensitivity, and specificity for predictors of MVI.

Result: In total 72 (58.06%) patients were detected with MVI among the 124 HCC patients. Univariate analysis showed that tumor size ( P  = 0.001), T stage ( P  < 0.001), maximum standardized uptake value (SUV max ) ( P  < 0.001), minimum standardized uptake value (SUV min ) ( P  = 0.031), mean standardized uptake value (SUV mean ) ( P  = 0.001), peak standardized uptake value (SUV peak ) ( P  = 0.001), tumor-to-liver ratio (SUV ratio ) ( P  = 0.010), total lesion glycolysis (TLG) ( P  = 0.006), metabolic tumor volume (MTV) ( P  = 0.011) and MVI were significantly different. Multivariate logistic regression showed that tumor size ( P  = 0.018), T stage ( P  = 0.017), TLG ( P  = 0.023), and MTV ( P  = 0.015) were independent predictors of MVI. In the receiver operating characteristic curve, TLG predicted MVI with an AUC value of 0.645. MTV predicted MVI with an AUC value of 0.635. Patients with tumor size ≥5 cm, T3-4, TLG > 400.67, and MTV > 80.58 had a higher incidence of MVI.

Conclusion: 18 F-FDG PET/CT metabolic parameters correlate with MVI and may be used as a noninvasive technique to predict MVI before LT in HCC patients.

Salivary gland scintigraphy (SGS) is an imaging technique to evaluate functional aspects of the salivary glands. First described in 1965, visual analyses of summed images and of time-activity curves generated through regions of interest (ROI) are still the main evaluation tools used in clinical practice. An alternative to ROI-based analysis is the use of parametric images, which are images generated through pixel-by-pixel calculation of parameters from the original frames. In this article, we would like to present some parametric images for SGS studies and how to create and use them. Two images, vascular flow and uptake velocity, were created using the intercept and slope of a linear model of the frames from after the first to fifth minute of acquisition. And two others, excretion fraction and absolute excretion, by subtraction and division methods of the frames before and after sialogogue stimulation. These images allow the visualization of the spatial distribution and heterogeneity of these quantitative parameters, favoring different forms of analysis and helping with image segmentation. After more than a year of using these images in daily routine, our general impression is that they have been very helpful. This article, however, still represents only our early experiences with this technique, and clinical studies are yet needed to better evaluate this method.

[ 75 Se]tauroselcholic acid (SeHCAT) retention measurement provides a noninvasive test for bile acid diarrhea (BAD); however, it is sensitive to the presence of other radionuclides. Two SeHCAT patients at the Royal Free Hospital (RFH) had significant discrepancies between the lower photopeak (111-159 keV) and central photopeak (242-296 keV) windows, indicating contamination with a radionuclide other than 75 Selenium. These patients had received lutetium-177 oxodotreotide ( 177 Lu-DOTATATE) therapy 98 and 151 days before their SeHCAT tests. Traces of 177 Lu may be retained longer than typically modeled, along with the contaminant 177m Lu. This work includes a retrospective audit to examine the prevalence of SeHCAT tests being affected by 177 Lu and phantom measurements to investigate the potential impact. Of 579 patients who received 177 Lu-DOTATATE therapy at our center, 11 subsequently attended for a SeHCAT test. The two previously identified patients may have had compromised SeHCAT results; however, the other patients had longer intervals between their therapy and test, and their tests are believed to be valid. Spectra were acquired from a phantom containing either a SeHCAT capsule or a mixture of 177 Lu/ 177m Lu representative of a patient >90 days after their treatment. The SeHCAT spectrum was scaled to produce simulated day-7 spectra, and the SeHCAT retention that would have been calculated if 177 Lu/ 177m Lu were present was determined. All SeHCAT measurement windows are affected by the 177 Lu/ 177m Lu, producing clinically significant errors. Patients requiring SeHCAT testing should be asked whether they have ever received 177 Lu-DOTATATE. Patient-specific background measurements may be useful for checking for significant levels of other radionuclides.

Objective: Visual assessments of amyloid-β PET, used for Alzheimer's disease (AD) diagnosis and treatment evaluation, require a careful approach when different PET ligands are utilized. Because the gray matter (GM) and white matter (WM) ligand bindings vary with age, the objective was to investigate the agreement between visual reads of 11 C- and 18 F-PET scans.

Methods: Cognitively unimpaired (CU) younger adults ( N  =   30; 39.5   ±   6.0   years), CU older adults ( N  =   30; 68.6   ±   5.9   years), and adults with AD ( N  =   22; 67.0   ±   8.5   years) underwent brain MRI, 11 C-Pittsburgh compound-B (PiB)-PET, and 18 F-flutemetamol-PET. Amyloid-β deposition was assessed visually by two nuclear medicine specialists on 11 C-PiB-PET and 18 F-flutemetamol-PET, and quantitatively by PET centiloids.

Results: Seventy-two 11 C-PiB-PET and 18 F-flutemetamol-PET visual reads were concordant. However, 1 18 F-flutemetamol-PET and 9 11 C-PiB-PET were discordant with quantitative values. In four additional cases, while 11 C-PiB-PET and 18 F-flutemetamol-PET visual reads were concordant, they were discordant with quantitative values. Disagreements in CU younger adults were only with 11 C-PiB-PET visual reads. The remaining disagreements were with CU older adults.

Conclusion: Age, GM/WM binding, amyloid-β load, and disease severity may affect visual assessments of PET ligands. Increase in WM binding with age causes a loss of contrast between GM and WM on 11 C-PiB-PET, particularly in CU younger adults, leading to false positivity. In CU older adults, increased WM signal may bleed more into cortical regions, hiding subtle cortical uptake, especially with 18 F-flutemetamol, whereas 11 C-PiB can detect true regional positivity. Understanding these differences will improve patient care and treatment evaluation in clinic and clinical trials.

Objective: This study was conducted to explore the differential diagnostic value of PET/computed tomography (PET/CT) combined with high-resolution computed tomography (HRCT) in predicting the invasiveness of ground-glass nodules (GGNs).

Materials and methods: This retrospective analysis included 67 patients (mean age 62.5 ± 8.4, including 45 females and 22 males) with GGNs who underwent preoperative 18 F-fluorodeoxyglucose ( 18 F-FDG) PET/CT and HRCT examinations between January 2018 and October 2022. Based on the postoperative pathological results of lung adenocarcinoma, the patients were classified into two groups: invasive adenocarcinoma (IAC) and non-IAC. Besides, the clinical and imaging information of these patients was collected. HRCT signs include the existence of air bronchial signals, vascular convergence, pleural indentation, lobulation, and spiculation. Moreover, the diameter of solid components (D Solid ), diameter of ground-glass nodules (D GGN ), and computed tomography values of ground-glass nodules (CT GGN ) were measured concurrently. Furthermore, the mean standardized uptake value, maximal standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis were assessed during PET/CT. Associations between invasiveness and these factors were evaluated using univariate and multivariate analyses.

Results: The results of logistic regression analysis demonstrated that D GGN , D Solid , consolidation tumor ratio (CTR), CT GGN , and SUVmax were independent predictors in the IAC group. The combined diagnosis based on these five predictors revealed that area under the curve was 0.825.

Conclusion: The D GGN , D Solid , CTR, CT GGN , and SUVmax in GGNs were independent predictors of IAC, and combining 18 F-FDG PET/CT metabolic parameters with HRCT may improve the predictive value of pathological classification in lung adenocarcinoma.

Objectives: The aim of this study is to investigate the jaw pathologies of patients with medication-related osteonecrosis of the jaw (MRONJ) using a computer program to assess the bone scan index (BSI), especially comparison of standardized uptake values (SUVs) with bone single-photon emission-computed tomography/computed tomography (SPECT/CT).

Methods: Sixty-three patients with MRONJ underwent bone SPECT/CT in this prospective study. BSI and high-risk hot spot as bone metastases in the patients with MRONJ were evaluated using a computer program for BSI that scanned SPECT/CT and automatically defined the data. The maximum and mean SUVs with SPECT/CT were obtained using commercially available software. Statistical analyses were performed by Pearson chi-square test, Mann-Whitney U -test, or one-way analysis of variance with Tukey's honestly significant difference test. A P value lower than 0.05 was considered statistically significant.

Results: The maximum and mean SUVs for a high-risk hot spot of the jaw with MRONJ [28.2 ± 10.2 and 11.7 ± 3.8; n  = 6 (6/63 : 9.5%)] were significantly higher than those for a low-risk hot spot [18.5 ± 6.4 and 6.2 ± 1.9; n  = 23 (23/63 : 36.5%)] and no-risk hot spot [14.2 ± 9.4 and 5.3 ± 5.1; n  = 34 (34/63 : 54.0%)], respectively.

Conclusion: The computer program for BSI indicated that 9.5% of the jaw with MRONJ were false positive of bone metastases. The study suggests that high-risk hot spots of the jaw with MRONJ depend on the SUVs.

Purpose: To investigate the diagnostic value of 18 F-fluorodeoxyglucose(FDG) PET/computed tomography (CT) for infiltrative subsolid nodules at different stages of lung adenocarcinoma and to explore predictive factors for invasive adenocarcinoma, providing compelling evidence for timely intervention.

Methods: A retrospective analysis was conducted on PET/CT imaging data of 170 subsolid nodules lesions confirmed postoperatively as lung adenocarcinoma or precursor glandular lesions. Lesions were categorized into preinvasive lesions including atypical adenomatous hyperplasia and adenocarcinoma in situ, microinvasive adenocarcinoma, and invasive adenocarcinoma. Compared the differences in imaging features and metabolic parameters among different groups and used a multifactor logistic regression model and receiver operating characteristic curve analysis to identify predictive factors for invasive adenocarcinoma.

Results: From preinvasive lesions through microinvasive adenocarcinoma to invasive adenocarcinoma, there was a gradual increase in nodule diameter, nodule area, and proportion of part-solid nodule. Statistical significance ( P  < 0.05) was observed in the rates of spiculation and pleural indentation between preinvasive lesions versus microinvasive adenocarcinoma and invasive adenocarcinoma groups. The maximum standardized uptake value and maximum standardized uptake ratio show statistically significant differences ( P  < 0.05) between the invasive adenocarcinoma group and the other groups. Logistic regression analysis indicated that nodule composition, nodule diameter, and maximum standardized uptake ratio were predictive factors for invasive adenocarcinoma ( P  < 0.05). For part-solid nodules, the longest diameter of the solid component has a high diagnostic value.

Conclusion: The imaging features of 18 F-FDG PET/CT contribute to the diagnosis of infiltrative subsolid nodules at different stages of lung adenocarcinoma, providing robust evidence for timely intervention.

Background: PET-Magnetic Resonance (PET-MR) imaging is an upcoming investigative modality with a few installations in Asia and only three in India. PET-Computed Tomography (PET-CT) is an established diagnostic cornerstone for oncological indications but with limited resolution for small lesions due to low soft-tissue contrast and additional radiation exposure.

Objective: Our primary objective was to evaluate the diagnostic performance of simultaneous PET-MR and PET-CT in lesion detection in oncological practice. Secondly to assess the referral pattern and study the clinical utility of PET-MR in a university hospital practice.

Materials and methods: A total of 100 consecutive biopsy-proven cancer patients (breast or lung malignancy with suspected metastases) underwent 18 F Fluorodeoxyglucose (FDG) PET-MR and PET-CT for staging as a single injection, double examination protocol. Morphological lesion detection on correlative imaging/histopathology was used as the gold standard. Analysing the referral pattern, a total of 9366 patients underwent simultaneous PET-MR imaging for various indications in the past 5 years since installation.

Results: 18 F FDG PET-MR detected 100% of primary tumours in breast/lung carcinoma patients while PET-CT was positive in 96%. Overall accuracy of nodal metastases detection for PET-MR and PET-CT was 96 and 88%, while for distant metastases the accuracy was 100 and 93%, respectively. FDG PET-MR proved more sensitive and specific than PET-CT for regional nodal ( P  = 0.011 and P  < 0.001) and distant metastases detection ( P  = 0.017 and P < 0.001, respectively). Analysing the general referral pattern for PET-MR, the majority were oncology referrals when compared to nononcological indications (66.5, 33.5%). About 66.24% were FDG based, followed by 68 Ga Prostate-Specific Membrane Antigen (PSMA) and dodecane tetraacetic acid (DOTA). The general utility of PET-MR was found incremental in better delineation of small lesions especially in head, neck, liver, brain and gynaecological malignancies.

Conclusion: In our past 5 years of PET-MR practice, we found that simultaneous PET-MR is a highly recommended ideal imaging technique for oncological and nononcological indications. It has excellent diagnostic performance with high sensitivity, specificity and accuracy when compared to PET-CT in primary tumour, nodal and distant metastases (TNM) staging in specific subgroup of breast and lung malignancy patients.

Objectives: Here, we have compiled all key statements derived from these guidelines and delved into details on which scenarios the diagnostic whole-body iodine scan (DxWBIS) might be useful.

Methods: We identified all relevant guidelines by searching the MEDLINE/PubMed databases, Google Scholar, and Ovid from 2006 onwards using keywords related to DxWBIS, RxWBIS, iodine scintigraphy, and iodine scan. We excluded case reports/series, original articles, and clinical trials while including guidelines or consensus opinions. Additionally, we reviewed existing literature to ensure no guidelines were overlooked.

Results: Overall, 23 relevant guidelines or consensus opinions discussed their views on the role of DxWBIS. Different indications for DxWBIS have been largely discussed in the last few years. However, the role of DxWBIS has been well established after treatment with 131I, with still limited evidence in the other clinical assessments.

Conclusions: Most guidelines find DxWBIS appealing for higher-risk patients, particularly those with a chance of recurrence; additional well-designed studies are required to address further indications.