Fluorine-18 Fluorodeoxyglucose Research Articles

Effect of Epidermal Growth Factor Receptor Mutation on Positron Emission Tomography/Computed Tomography in Lung Cancer.

This study analyzed the effect of epidermal growth factor receptor (EGFR) mutations on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) results in lung cancer and the pathological findings in patients subjected to surgery. A total of 210 patients diagnosed with lung cancer by F-18 FDG PET/CT at Inje University Busan Paik Hospital between January 2018 and December 2023 were recruited. EGFR mutation tests were performed on biopsy specimens. Overall, 78 patients (37.1%) with EGFR mutations were included in this study. Twenty-seven patients (12.9%) had distant metastases at the time of diagnosis. Of all patients, 69 (32.9%) underwent surgery at our hospital, and their pathological findings were analyzed. The maximum standardized uptake value (SUVmax) of F-18 FDG PET/CT was <10 in patients with EGFR mutations. Patients with EGFR mutations were not commonly diagnosed with diabetes. When analyzing the pathological findings after surgery in the 69 patients, adenocarcinoma was more common in those with EGFR mutations. In contrast, perineural invasion was more common in patients without EGFR mutations. When analyzing the results of 69 patients with postoperative pathology, 25 relapsed during the median follow-up of 21.7 months (range=0.9-58.4 months). Patients who underwent surgery and had EGFR mutations (n=26) exhibited lower recurrence rates compared to those without EGFR mutations. Disease-free survival was longer in patients with EGFR mutations. In non-small-cell lung cancer with an EGFR mutation, the F-18 FDG PET/CT SUVmax value and the probability of recurrence were lower. EGFR mutations are associated with low-glucose metabolism.

The value of dual time-point fluorine-18 fluorodeoxyglucose PET/computed tomography imaging in predicting lymph node metastasis in non-small cell lung cancer patients.

The purpose of this study was to analyze the correlation between specified dual time-point fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) imaging parameters and pathological characteristics in non-small cell lung cancer (NSCLC) patients. This study retrospectively analyzed 47 patients with NSCLC. All patients underwent dual time-point 18F-FDG PET/CT imaging. We obtained the metabolic parameters, standardized uptake value (SUV) maximum, SUVmean, delayed standardized uptake value (DSUV) maximum, DSUVmean, delay index standardized uptake value (DISUV) maximum, and DISUVmean, of the primary tumor. The tumor size was measured by CT. All lymph nodes had a definite pathological diagnosis. We next evaluated the status of the lymph node metastases (LNM) and the correlations between metabolic parameters and clinical characteristics. Receiver operating characteristic curves were drawn for the prediction of LNM. We found that the DSUVmax, DISUVmax, DSUVmean, and tumor size were significantly related to LNM (P = 0.036, 0.009, and 0.049, respectively). Multivariate analysis revealed that tumor size and DISUVmax were independent risk factors for LNM in lung cancer patients. According to the receiver operating characteristic curve analysis, the optimal cutoff values for DISUVmax and tumor size were 0.33 and 2.8 cm, respectively. When these two parameters were combined, the area under the curve for predicting LNM in NSCLC was 0.768, and the sensitivity was 95.7% for predicting LNM in lung cancer patients. We further allocated the patients to three groups: the high-risk group (tumor size ≥ 2.8 cm, DISUVmax ≥ 0.33), the moderate-risk group (tumor size ≥ 2.8 cm, DISUVmax < 0.33, or tumor size < 2.8 cm, DISUVmax ≥ 0.33), and the low-risk group (tumor size < 2.8 cm, DISUVmax < 0.33). The rates of LNM were 70, 50, and 0%, respectively. Tumor size and DISUVmax are risk factors for predicting LNM, and they are more useful in combination. Compared with standard PET/CT imaging, dual time-point PET/CT imaging has added value in predicting LNM in NSCLC patients.

Predictive value of SUVmax from initial 18F-FDG PET/CT scans for treatment outcomes in endometrial cancer patients undergoing fertility sparing management

ObjectiveTo evaluate whether the maximum standardized uptake value (SUVmax) from initial 18F-FDG PET/CT (fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography) scans could be a predictor of complete response and recurrence in...

Association of Localizing 18F-FDG-PET Hypometabolism and Outcome Following Epilepsy Surgery: Systematic Review and Meta-Analysis.

Although commonly used in the evaluation of patients for epilepsy surgery, the association between the detection of localizing 18fluorine fluorodeoxyglucose PET (18F-FDG-PET) hypometabolism and epilepsy surgery outcome is uncertain. We conducted a systematic review and meta-analysis to determine whether localizing 18F-FDG-PET hypometabolism is associated with favorable outcome after epilepsy surgery. A systematic literature search was undertaken. Eligible publications included evaluation with 18F-FDG-PET before epilepsy surgery, with ≥10 participants, and those that reported surgical outcome at ≥12 months. Random-effects meta-analysis was used to calculate the odds of achieving a favorable outcome, defined as Engel class I, International League Against Epilepsy class 1-2, or seizure-free, with localizing 18F-FDG-PET hypometabolism, defined as concordant with the epilepsy surgery resection zone. Meta-regression was used to characterize sources of heterogeneity. The database search identified 8,916 studies, of which 98 were included (total patients n = 4,104). Localizing 18F-FDG-PET hypometabolism was associated with favorable outcome after epilepsy surgery for all patients with odds ratio (OR) 2.68 (95% CI 2.08-3.45). Subgroup analysis yielded similar findings for those with (OR 2.64, 95% CI 1.54-4.52) and without epileptogenic lesion detected on MRI (OR 2.49, 95% CI 1.80-3.44). Concordance with EEG (OR 2.34, 95% CI 1.43-3.83), MRI (OR 1.69, 95% CI 1.19-2.40), and triple concordance with both (OR 2.20, 95% CI 1.32-3.64) was associated with higher odds of favorable outcome. By contrast, diffuse 18F-FDG-PET hypometabolism was associated with worse outcomes compared with focal hypometabolism (OR 0.34, 95% CI 0.22-0.54). Localizing 18F-FDG-PET hypometabolism is associated with favorable outcome after epilepsy surgery, irrespective of the presence of an epileptogenic lesion on MRI. The extent of 18F-FDG-PET hypometabolism provides additional information, with diffuse hypometabolism associated with worse surgical outcome than focal 18F-FDG-PET hypometabolism. These findings support the incorporation of 18F-FDG-PET into routine noninvasive investigations for patients being evaluated for epilepsy surgery to improve epileptogenic zone localization and to aid patient selection for surgery.

Fluorine-18 fluorodeoxyglucose uptake change in liver, mediastinal blood pool, and lymphoid cell-rich organs during programmed cell death-1 immunotherapy in lymphoma.

The aim of this study was to evaluate metabolism change in reference organs (liver and mediastinum) and lymphoid cell-rich organs (spleen and bone marrow) during programmed cell death-1 immunotherapy in relapsed or refractory lymphoma patients. A total of 66 patients with baseline and serial monitoring fluorodeoxyglucose (FDG) PET/computed tomography scans were retrospectively enrolled. Mean standardized uptake value (SUV) and maximum SUV of evaluated organs were obtained by two reviewers, and their association with tumor burden and clinical response were evaluated. Immune-related adverse events detected by FDG PET/computed tomography were also recorded. The SUV values of reference organs and lymphoid cell-rich organs did not change significantly during the immunotherapy process. The intersubject variability of these values ranged from 13.0 to 28.5%. Meanwhile, metabolism of reference organs was affected by neither the tumor burden nor clinical response. SUV change of lymphoid cell-rich organs was associated with clinical response to immunotherapy. Responders showed decreased metabolism, while nonresponders showed a reverse trend (spleen SUVmaximum: -0.30 ± 0.47 vs. 0.18 ± 0.39, P = 0.001, spleen SUVmean: -0.24 ± 0.39 vs. 0.14 ± 0.31, P = 0.001; and bone marrow SUVmaximum: -0.14 ± 0.37 vs. 0.07 ± 0.46, P = 0.042, respectively). The influence of immune-related adverse events on the SUV change in evaluated organs was NS. During programmed cell death-1 immunotherapy, metabolism change of reference organs is influenced neither by tumor burden nor by clinical response, while FDG uptake change of lymphoid cell-rich organs is significantly associated with clinical response.

Prospective pilot study utilizing changes in quantitative values obtained on serial fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) in dogs with appendicular osteosarcoma before and after stereotactic body radiation therapy (SBRT) and carboplatin chemotherapy to assess for prediction of survival and therapeutic effectiveness.

Serial fluorine 18 fluorodeoxyglucose (18F-FDG) positron emission tomography-CT (PET/CT) is commonly used in human oncology to prognosticate and evaluate for therapeutic effectiveness. In this pilot study, dogs with naturally occurring appendicular osteosarcoma were evaluated with serial 18F-FDG PET/CT in an attempt to assess for response to therapy, prognostic factors, and appropriateness of imaging intervals. Fourteen dogs were enrolled in the trial. All dogs had the initial 18F-FDG PET/CT (PET1), with nine dogs having their end-of-therapy 18F-FDG PET/CT (EoT PET) 3 months after stereotactic body radiation therapy (SBRT) to the primary tumor. The median percent change from the PET1 to the EoT PET for the standard uptake value maximum (SUVmax%) was -58% (range: -17 to -88%), metabolic tumor volume (MTV%) was -99.8% (range: -65 to -100%), and total lesion glycolysis (TLG%) was -99.8% (range: -75 to -100%), all of which were significant (P<.05, <.05, and <.05, respectively). On evaluation, it was found that volumes of GTV and CTV were significant for survival (P<.05 and <.05), MTV1, TLG1, and SUVmax on the EoT PET (SUVmaxEoT) were predictive of metastasis (P<.05), and the SUVmax% was significantly correlated to the time to first event (P<.05). Based on this data, serial 18F-FDG PET/CT performed 3 months after SBRT can show a significant reduction in avidity, and the quantitative data collected may help predict metastatic disease in canine appendicular osteosarcoma.

Cardiac metastasis of lung cancer diagnosed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)

Cardiac metastasis of lung cancer diagnosed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)

Sociodemographic factors and Child Opportunity Index disparities associated with missed care opportunities in pediatric patients with lymphoma and leukemia referred for FDG-PET/CT.

Little data exists on the association of missed care opportunities (MCOs) in children referred for nuclear medicine/nuclearoncology imaging examinations and socioeconomic disparities. To determine the prevalence of MCOs in children with lymphoma/leukemia scheduled for fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the impact of sociodemographic factors and Child Opportunity Index (COI). Retrospective analysis of MCOs in children with lymphoma/leukemia scheduled for FDG-PET/CT (2012 to 2022)was performed. In univariate analysis, patient, neighborhood, and appointment data were assessed across MCOs and completed appointments. Logistic regression evaluated independent effects of patient-, neighborhood-, and appointment-level factors with MCOs. Two-sided P-value < .05 was considered statistically significant. In 643 FDG-PET/CT appointments (n = 293 patients; median age 15years (IQR 11.0-17.0years); 37.9% female), there were 20 MCOs (3.1%) involving 16 patients. Only 8.2% appointments involved Black/African American non-Hispanic/Latino patients, yet they made up a quarter of total MCOs. Patients living in neighborhoods with very low or low COI experienced significantly higher MCOs versus zip codes with very high COI (6.9% vs. 0.8%; P = 0.02). Logistic regression revealed significantly increased likelihood of MCOs for patients aged 18 to 21 [odds ratio (OR) 4.50; 95% CI 1.53-13.27; P = 0.007], Black/African American non-Hispanic/Latino (OR 3.20; 95% CI 1.08-9.49; P = 0.04), zip codes with very low or low COI (OR 9.60; 95% CI 1.24-74.30; P = 0.03), and unknown insurance status. Children with lymphoma/leukemia, living in zip codes with very low or low COI, and who identified as Black/African American non-Hispanic/Latino experienced more MCOs. Our study supports the need to address intersecting sociodemographic, neighborhood, and health system factors that will improve equitable access to necessary healthcare imaging for children.

Unexpected focal fluorodeoxyglucose uptake in main organs; pass through or pass by?

Since the inception of fluorine-18 fluorodeoxyglucose (F-18 FDG), positron emission tomography/computed tomography (PET/CT) utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of oncology, with global prevalence in clinical practice. Given that a single Torso PET/CT scan encompasses the anatomical region from the skull base to the upper thigh, the detection of incidental abnormal focal hypermetabolism in areas of limited clinical interest is both feasible and not uncommon. Numerous investigations have been undertaken to delineate the distinctive features of these findings, yet the outcomes have proven inconclusive. The incongruent results of these studies present a challenge for physicians, leaving them uncertain about the appropriate course of action. This article provides a succinct overview of the characteristics of fluorodeoxyglucose, followed by a comprehensive discussion of the imaging findings and clinical significance associated with incidental focal abnormal F-18 FDG activity in several representative organs. In conclusion, while the prevalence of unrecognized malignancy varies across organs, malignancies account for a substantial proportion, ranging from approximately one-third to over half, of incidental focal uptake. In light of these rates, physicians are urged to exercise vigilance in not disregarding unexpected uptake, facilitating more assured clinical decisions, and advocating for further active evaluation.

Validation of the 2018 FIGO staging system for stage IIIC cervical cancer by determining the metabolic and radiomic heterogeneity of primary tumors based on 18F-FDG PET/CT.

This study aimed to validate the 2018 FIGO staging system of cervical cancer (CC) by determining the metabolic and radiomic heterogeneity of primary tumors between stage IIIC1 and IIIC2. 168 patients with squamous cell CC underwent pre-treatment fluorine-18 fluorodeoxyglucose positron emission computed tomography (18F-FDG PET/CT) and were randomly allocated to training and testing cohorts with a 7:3 ratio. Radiomics features were extracted from the primary tumors based on CT and PET data. Ten metabolic parameters of the primary tumors were also assessed. After feature selection, three logistic regression radiomics models, involving (1) 2 CT features, (2) 3 PET features, and (3) 2 CT features + 3 PET features, respectively, and one random forest model were established. Finally, area under the curve (AUC) values and calibration curves were used to evaluate the 4 models. The IIIC1 and IIIC2 groups did not differ significantly in age, weight, height, or the 10 major metabolic parameters (P > 0.05). The AUCs of the 4 models were 0.577, 0.639, 0.763, and 0.506, respectively, in the training cohort, and 0.789, 0.699, 0.761, and 0.538, respectively, in the testing cohort. The model fit of the logistic regression model based on CT + PET data was good in both the training and testing cohorts. Our study offers additional diagnostic options for PALN metastasis, which could impact treatment decisions. Our results indirectly support the conclusions of previous studies recommending that primary tumors should be considered during IIIC staging.

Evaluating Prognosis of Gastrointestinal Metastatic Neuroendocrine Tumors: Constructing a Novel Prognostic Nomogram Based on NETPET Score and Metabolic Parameters from PET/CT Imaging.

The goal of this study is to compare the prognostic performance of NETPET scores, based on gallium-68 DOTANOC (68Ga-DOTANOC) and fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography-Computed Tomography (PET-CT), and PET-CT metabolic parameters in metastatic gastrointestinal neuroendocrine tumors (GI-NET), while constructing and validating a nomogram derived from dual-scan PET-CT. In this retrospective study, G1-G3 GI-NET patients who underwent 68Ga-DOTANOC and 18F-FDG PET scans were enrolled and divided into training and internal validation cohorts. Three grading systems were constructed based on NETPET scores and standardized uptake value maximum (SUVmax). LASSO regression selected variables for a multivariable Cox model, and nomograms predicting progression-free survival (PFS) and overall survival (OS) were created. The prognostic performance of these systems was assessed using time-dependent receiver-operating characteristic (ROC) curves, concordance index (C-index), and other methods. Nomogram evaluation involved calibration curves, decision curve analysis (DCA), and the aforementioned methods in both cohorts. In this study, 223 patients (130 males; mean age ± SD: 52.6 ± 12 years) were divided into training (148) and internal validation (75) cohorts. Dual scans were classified based on NETPET scores (D1-D3). Single 68Ga-DOTANOC and 18F-FDG PET-CT scans were stratified into S1-S3 and F1-F3 based on SUVmax. The NETPET score-based grading system demonstrated the best OS and PFS prediction (C-index, 0.763 vs. 0.727 vs. 0.566). Nomograms for OS and PFS exhibited superior prognostic performance in both cohorts (all AUCs > 0.8). New classification based on NETPET score predicts patient OS/PFS best. PET-CT-based nomograms show accurate OS/PFS forecasts.

Musculoskeletal Pitfalls on Molecular Imaging Studies of Oncologic Patients: How to Stay Out of Trouble.

An increasing amount of molecular imaging studies are ordered each year for an oncologic population that continues to expand and increase in age. The importance of these studies in dictating further care for oncologic patients underscores the necessity of differentiating benign from malignant findings, particularly for a population in whom incidental findings are common. The aim of this review is to provide pictorial examples of benign musculoskeletal pathologies which may be found on molecular imaging and which may be mistaken for malignant processes. Imaging examples are provided in the form of radiographs, bone scintigraphy, computed tomography, and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scans. Special attention is paid to specific features that help narrow the differential diagnosis and distinguish benign from malignant processes, with the goal of avoiding unnecessary invasive procedures.

Radiologic Parameters Predicting the Histologic Invasiveness of Pure Ground-glass Nodules

BackgroundThis study aimed to investigate the diagnostic performance of combined computed tomography (CT) and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for predicting histologic invasiveness of pure ground-glass nodules (pGGNs). MethodsThe study analyzed 91 patients who underwent resection of pGGNs and examined the correlation of pathologic invasiveness with preoperative CT and FDG PET findings. ResultsOverall, 24, 36, and 31 patients had adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAD), respectively. Compared with AIS and MIA, IAD was significantly correlated with larger CT size (P = .001), maximum CT value (P = .026), and high maximum standardized uptake value (SUVmax; P < .001). Multivariable logistic analyses revealed that CT size (odds ratio [OR], 3.848; P = .019) and SUVmax (OR, 4.968; P = .009) were independent predictors of histologic invasiveness. Receiver operating characteristic curve analysis revealed that a cutoff CT size value of 18 mm predicted histologic invasiveness with a sensitivity and specificity of 65% and 80%, respectively; similarly, a cutoff SUVmax value of 1.5 predicted histologic invasiveness with a sensitivity and specificity of 61% and 90%, respectively. Of 20 lesions with CT size ≥18 mm and SUVmax ≥1.5, 16 (80%) were IAD. Of 54 lesions with CT size <18 mm and SUVmax <1.5, 46 (85%) were non-IAD lesions. Furthermore, all pGGNs with SUVmax ≥2.5 were IAD. ConclusionsCT size and SUVmax were significantly correlated with the histologic invasiveness of pGGNs. These factors may aid in determining optimal surgical procedures.

Novel Functional Radiomics for Prediction of Cardiac Positron Emission Tomography Avidity in Lung Cancer Radiotherapy.

Traditional methods of evaluating cardiotoxicity focus on radiation doses to the heart. Functional imaging has the potential to provide improved prediction for cardiotoxicity for patients with lung cancer. Fluorine-18 (18F) fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) imaging is routinely obtained in a standard cancer staging workup. This work aimed to develop a radiomics model predicting clinical cardiac assessment using 18F-FDG PET/CT scans before thoracic radiation therapy. Pretreatment 18F-FDG PET/CT scans from three study populations (N = 100, N = 39, N = 70) were used, comprising two single-institutional protocols and one publicly available data set. A clinician (V.J.) classified the PET/CT scans per clinical cardiac guidelines as no uptake, diffuse uptake, or focal uptake. The heart was delineated, and 210 novel functional radiomics features were selected to classify cardiac FDG uptake patterns. Training data were divided into training (80%)/validation (20%) sets. Feature reduction was performed using the Wilcoxon test, hierarchical clustering, and recursive feature elimination. Ten-fold cross-validation was carried out for training, and the accuracy of the models to predict clinical cardiac assessment was reported. From 202 of 209 scans, cardiac FDG uptake was scored as no uptake (39.6%), diffuse uptake (25.3%), and focal uptake (35.1%), respectively. Sixty-two independent radiomics features were reduced to nine clinically pertinent features. The best model showed 93% predictive accuracy in the training data set and 80% and 92% predictive accuracy in two external validation data sets. This work used an extensive patient data set to develop a functional cardiac radiomic model from standard-of-care 18F-FDG PET/CT scans, showing good predictive accuracy. The radiomics model has the potential to provide an automated method to predict existing cardiac conditions and provide an early functional biomarker to identify patients at risk of developing cardiac complications after radiotherapy.

Follicular Thyroid Carcinoma with Unusual Mandible Metastasis.

Follicular thyroid cancer is the second-most common type of thyroid cancer after papillary thyroid cancer. Metastases to the mandible and maxillofacial region are rare. Our study presents a 55-year-old patient who underwent total thyroidectomy for follicular thyroid cancer and subsequent radioactive iodine therapy. Sixteen years after diagnosis, elevated thyroglobulin levels suggested disease recurrence. Using advanced imaging techniques - Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan, bone scintigraphy, and posttreatment I-131 scan-an unexpected metastatic site was identified: the left mandibular condyle. A biopsy confirmed the presence of metastatic follicular thyroid cancer.

Semiquantitative 18F-FDG PET/CT in monitoring glucocorticoid response of immunoglobulin G4-related effusive constrictive pericarditis: a case report

BackgroundImmunoglobulin G4 (IgG4)-related effusive constrictive pericarditis (ECP) is a rare manifestation of IgG4-related disease (IgG4-RD). It can lead to persistent pericardial fibrosis, resulting in cardiac tamponade, diastolic dysfunction, and heart failure. Glucocorticoids are the primary treatment for effectively reducing inflammation and preventing fibrosis. However, guidelines for monitoring treatment response are lacking and tapering glucocorticoid therapy for specific target organs remains a challenge. Recent studies on IgG4-RD have demonstrated that semiquantitative measurements of fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in the main involved organs in positron emission tomography/computed tomography (PET/CT) scanning are correlated to disease activity. We present a case of IgG4-related ECP to demonstrate the usefulness of 18F-FDG PET/CT for diagnosing and treatment follow-up of IgG4-related ECP.Case presentationHerein, a 66-year-old woman diagnosed with IgG4-related ECP presented with breathlessness, leg swelling, rales, and fever. Laboratory tests revealed markedly elevated levels of C-reactive protein, and transthoracic echocardiography revealed constrictive physiology with effusion. High IgG4 levels suggested an immune-related pathogenesis, while viral and malignant causes were excluded. Subsequent pericardial biopsy revealed lymphocyte and plasma cell infiltration in the pericardium, confirming the diagnosis of IgG4-related ECP. 18F-FDG PET/CT revealed increased uptake of 18F-FDG in the pericardium, indicating isolated cardiac involvement of IgG4-RD. Treatment with prednisolone and colchicine led to a rapid improvement in the patient’s condition within a few weeks. Follow-up imaging with 18F-FDG PET/CT after 3 months revealed reduced inflammation and improved constrictive physiology on echocardiography, leading to successful tapering of the prednisolone dose and discontinuation of colchicine.ConclusionThe rarity of IgG4-related ECP and possibility of multiorgan involvement in IgG4-RD necessitates a comprehensive diagnostic approach and personalized management. This case report highlights the usefulness of 18F-FDG PET/CT in the diagnosis and treatment follow-up of isolated pericardial involvement in IgG4-RD.

Predicting programmed death-ligand 1 (PD-L1) expression with fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) metabolic parameters in resectable non-small cell lung cancer.

Programmed death-ligand 1 (PD-L1) expression is a predictive biomarker for immunotherapy in non-small cell lung cancer (NSCLC). PD-L1 and glucose transporter 1 expression are closely associated, and studies demonstrate correlation of PD-L1 with glucose metabolism. The aim of this study was to investigate the association of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) metabolic parameters with PD-L1 expression in primary lung tumour and lymph node metastases in resected NSCLC. We conducted a retrospective analysis of 210 patients with node-positive resectable stage IIB-IIIB NSCLC. PD-L1 tumour proportion score (TPS) was determined using the DAKO 22C3 immunohistochemical assay. Semi-automated techniques were used to analyse pre-operative [18F]FDG-PET/CT images to determine primary and nodal metabolic parameter scores (including max, mean, peak and peak adjusted for lean body mass standardised uptake values (SUV), metabolic tumour volume (MTV), total lesional glycolysis (TLG) and SUV heterogeneity index (HISUV)). Patients were predominantly male (57%), median age 70 years with non-squamous NSCLC (68%). A majority had negative primary tumour PD-L1 (TPS < 1%; 53%). Mean SUVmax, SUVmean, SUVpeak and SULpeak values were significantly higher (p < 0.05) in those with TPS ≥ 1% in primary tumour (n = 210) or lymph nodes (n = 91). However, ROC analysis demonstrated only moderate separability at the 1% PD-L1 TPS threshold (AUCs 0.58-0.73). There was no association of MTV, TLG and HISUV with PD-L1 TPS. This study demonstrated the association of SUV-based [18F]FDG-PET/CT metabolic parameters with PD-L1 expression in primary tumour or lymph node metastasis in resectable NSCLC, but with poor sensitivity and specificity for predicting PD-L1 positivity ≥ 1%. Whilst SUV-based fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography metabolic parameters may not predict programmed death-ligand 1 positivity ≥ 1% in the primary tumour and lymph nodes of resectable non-small cell lung cancer independently, there is a clear association which warrants further investigation in prospective studies. Non-applicable KEY POINTS: • Programmed death-ligand 1 immunohistochemistry has a predictive role in non-small cell lung cancer immunotherapy; however, it is both heterogenous and dynamic. • SUV-based fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) metabolic parameters were significantly higher in primary tumour or lymph node metastases with positive programmed death-ligand 1 expression. • These SUV-based parameters could potentially play an additive role along with other multi-modal biomarkers in selecting patients within a predictive nomogram.

The Neuroprotective Effect of Therapeutic Hypothermia in Cognitive Impairment of an Ischemia/Reperfusion Injury Mouse Model.

Background and Objectives: Therapeutic hypothermia (TH) shows promise as an approach with neuroprotective effects, capable of reducing secondary brain damage and intracranial pressure following successful mechanical thrombectomy in the acute phase. However, its effect on cognitive impairment remains unclear. This study investigated whether TH can improve cognitive impairment in a mouse model of transient middle cerebral artery occlusion followed by reperfusion (tMCAO/R). Materials and Methods: Nine-week-old C57BL/6N mice (male) were randomly assigned to three groups: sham, tMCAO/R, and tMCAO/R with TH. Cognitive function was assessed 1 month after model induction using the Y-maze test, and regional cerebral glucose metabolism was measured through positron emission tomography with fluorine-18 fluorodeoxyglucose. Results: tMCAO/R induced cognitive impairment, which showed improvement with TH. The TH group exhibited a significant recovery in cerebral glucose metabolism in the thalamus compared to the tMCAO/R group. Conclusions: These findings indicate that TH may hold promise as a therapeutic strategy for alleviating ischemia/reperfusion-induced cognitive impairment.

Clinical application of combination [11C]C-methionine and [13N]N-ammonia PET/CT in recurrent functional pituitary adenomas with negative MRI or [18F]F-FDG PET/CT

BackgroundWe assessed the value of positron emission tomography/computed tomography (PET/CT) with [13N]N-ammonia ([13N]N-NH3) and [11C]C-methionine ([11C]C-MET) for the evaluation and management of recurrent secreting pituitary adenoma, which could not be detected by magnetic resonance imaging (MRI) or fluorine-18 fluorodeoxyglucose ([18F]F-FDG) PET.MethodsNine consecutive patients with biochemical and clinical evidence of active recurrent tumor not detected by MRI and [18F]F-FDG PET were enrolled in this study. All of the patients underwent [13N]N-NH3 and [11C]C-MET PET/CT, after which the pattern of tracer uptake was studied, the tumor position was located, and a clinical decision was made.ResultsIn general, [11C]C-MET had a higher uptake in pituitary adenomas (PAs) than that in pituitary tissues, while [13N]N-NH3 had a higher uptake in pituitary tissue than in pituitary adenomas. Increased [11C]C-MET uptake was observed in all nine PAs and three pituitary tissues, while all pituitary tissues and only one pituitary adenoma showed increased [13N]N-NH3 uptake. Four patients had concordant imaging and surgical findings indicative of biochemical remission without hypopituitarism after treatment. Radiotherapy was adopted in two patients, medication in another two, and follow-up observation in one case.ConclusionCombined [11C]C-MET and [13N]N-NH3 PET/CT is effective in the differentiation of PAs from pituitary tissue in recurrent functional PAs with negative MRI or [18F]F-FDG PET. These results provide a valuable reference for further disease management.

Prognostic thresholds of fluorine-18 fluorodeoxyglucose-positron emission tomography mean and maximum standardized uptake values for survival and nodal involvement in lung neuroendocrine neoplasms.

The mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose-positron emission tomography are prognostic biomarkers for survival and nodal involvement in non-small-cell lung cancer but their prognostic value in lung neuroendocrine neoplasms (NENs) remains unexplored. In this study, we aimed to examine whether they are also prognostic biomarkers for survival and nodal involvement in lung NENs. We retrospectively studied patients with typical carcinoid, atypical carcinoid or large cell neuroendocrine carcinoma who had been radically resected at our institution between 2008 and 2020. We measured SUVmean and SUVmax on all primary tumours and lymph nodes that were clinically and/or pathologically involved. We dichotomized the patients into groups of high or low SUVmean and SUVmax of the primary tumour using time-dependent receiver operating characteristic curves and compared their overall survival using Kaplan-Meier curves and Cox models. Lastly, we predicted the patients' pathological nodal status with SUVmean and SUVmax of the lymph nodes using binomial logistic models. The study included 245 patients. Patients died earlier if their SUVmean of the primary tumour exceeded 3.9 [hazard ratio 1.97, 95% confidence interval (CI) 1.27-3.04, P = 0.002] or SUVmax exceeded 5.3 (hazard ratio 1.85, 95% CI 1.20-2.87, P = 0.006). Likewise, patients had a higher risk of pathological nodal involvement if their SUVmean of the lymph nodes exceeded 3.3 (odds ratio 10.00, 95% CI 2.59-51.01, P = 0.002) or SUVmax exceeded 4.2 (odds ratio 4.00, 95% CI 1.20-14.65, P = 0.028). The fluorine-18 fluorodeoxyglucose-positron emission tomography SUVmean and SUVmax are strong prognostic biomarkers for survival and nodal involvement in lung NENs and could be important guides for making treatment decisions.