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Abstract: A 72-year-old woman, who was a nonsmoker, presented with chest distress persisting for over 10 days. Plain chest CT revealed thickening of the left pleura accompanied by hydrothorax. Subsequent 18 F-FDG PET/CT showed irregular thickening involving the visceral, parietal, and interlobular pleura on the left side, with diffuse high avidity of 18 F-FDG. The left pleural mesothelioma was suspected initially, but pathological examination from biopsied specimen later confirmed a thoracic SMARCA4-deficient undifferentiated tumor., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 72-year-old man presented with a painless penile mass for 3 months. Contrast-enhanced CT revealed heterogeneous enhancement, whereas 18 F-FDG PET/CT displayed inhomogeneous 18 F-FDG accumulation in the lesion without other abnormal activity. The histopathological examination from biopsied specimen confirmed the diagnosis of a plasmacytoma. However, the subsequent tests, including serum/urine immunofixation electrophoresis, serum/urine free light chain assay, and bone marrow smear/biopsy, did not show any abnormalities. The conclusive diagnosis was a solitary extramedullary plasmacytoma of the penis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Dedifferentiated liposarcoma is an extremely rare and highly malignant tumor. We demonstrated a case of a 75-year-old man with significantly PSMA-avid and mildly FDG uptake-dedifferentiated liposarcoma in the retroperitoneal area. The double-tracer (PSMA and FDG) PET scans could further contribute to differential diagnosis and the following treatment strategy for patients who were suspected with prostate cancer metastases and other malignant tumors simultaneously., Competing Interests: Conflicts of interest and sources of funding: This study was supported by the National High Level Hospital Clinical Research Funding (Interdepartmental Research Project of Peking University First Hospital) (2023IR50) and National High Level Hospital Clinical Research Funding (Scientific and Technological Achievements Transformation Incubation Guidance Fund Project of Peking University First Hospital:2023CX02)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

18 F-FDG uptake rate constant K i is the main physiology parameter measured in dynamic PET studies. A model-independent graphical analysis using Patlak plot with plasma input function (PIF) is a standard approach used to estimate K i . The PIF is the 18 F-FDG time activity curve (TAC) in plasma that is obtained by serial arterial blood sampling. The purpose of the study is to evaluate a Patlak plot-based optimization approach with reduced blood samples for noninvasive quantification of dynamic 18 F-FDG PET imaging. Eight 60 min rhesus monkey brain dynamic 18 F-FDG PET scans with arterial blood samples were collected. The measured PIF (mPIF) was determined by arterial blood samples. TACs of seven cerebral regions of interest were generated from each study. With a given number of blood samples, the population-based PIF (pPIF) was determined by either interpolation or extrapolation method using scale calibrated population mean of normalized PIF. The optimal sampling scheme with given blood sample size was determined by maximizing the correlations between the K i estimated from pPIF and those obtained by mPIF. A leave-two-out cross-validation method was used for evaluation. The linear correlations between the K i estimates from pPIF with optimal sampling schemes and those from mPIF were: K i (pPIF 1 sample at 40 min) = 1.015 K i (mPIF) - 0.000, R 2  = 0.974; K i (pPIF 2 samples at 35 and 50 min) = 1.052 K i (mPIF) - 0.001, R 2  = 0.976; K i (pPIF 3 samples at 12, 40, and 50 min) = 1.030 K i (mPIF) - 0.000, R 2  = 0.985; and K i (pPIF 4 samples at 10, 20, 40, and 50 min) = 1.016 K i (mPIF)- 0.000, R 2  = 0.993. As the sample size became greater or equal to 4, the K i estimates from pPIF with the optimal protocol were almost identical to those from mPIF. The Patlak plot-based optimization approach is a reliable method to estimate PIF for noninvasive quantification of non-human primate dynamic 18 F-FDG PET imaging and is potentially extendable to further translational human studies.

Purpose: To explore the potential parameters from F-FDG PET/CT that might be associated with the epidermal growth factor receptor (EGFR) gene mutation status in lung adenocarcinoma (ADC) patients., Methods: Data of the test cohort of 191 patients and the validation cohort of 55 patients with newly diagnosed ADC were retrospectively reviewed. All patients underwent F-FDG PET/CT scans and EGFR mutation tests prior to treatment. The metabolic parameters obtained from F-FDG PET/CT combining with clinical characteristics were analyzed by using univariate and multivariate logistic regression analyses. Then two cohorts were enrolled to validate the predictive model by area under the receiver-operating characteristic curve (AUC), respectively., Results: EGFR mutation-positive was seen of 33.0% (63/191) and 32.7% (18/55) in two cohorts, respectively. In univariate analysis, female, nonsmokers, metabolic parameters of primary tumor [mean standardized uptake value, metabolic tumor volume (pMTV), and total lesion glycolysis], non-necrosis of primary tumor, and serum tumor markers [carbohydrate antigen 19-9, squamous cell carcinoma antigen, and precursor of gastrin releasing peptide (proGRP)] were significantly relevant with EGFR mutation. In multivariate analysis with adjustment of age and TNM stage, pMTV (<8.13 cm), proGRP (≥38.44 pg/ml) and women were independent significant predictors for EGFR mutation. The AUC for the predictive value of these factors was 0.739 [95% confidence interval (CI) 0.665-0.813] in the cohort of 191 patients and 0.716 (95% CI 0.567-0.865) in the cohort of 55 patients, respectively., Conclusion: Low pMTV (<8.13 cm) was an independent predictor and could be integrated with women and high proGRP (≥38.44 pg/ml) to enhance the discriminability on the EGFR mutation status in ADC patients.

Aim: To assess the potential of using preoperative 18 F-FDG PET/CT to predict the prognosis of patients with clear cell renal cell carcinoma (ccRCC) after nephrectomy., Methods: Sixty-nine patients with newly diagnosed ccRCC who underwent 18 F-FDG PET/CT prior to surgery were retrospectively reviewed. The metabolic parameters of maximum standardized uptake value (SUVmax) and tumor-to-liver ratio (TLR) from 18 F-FDG PET/CT were obtained. Clinicopathological characteristics, including the World Health Organization/the International Society of Urological Pathology (WHO/ISUP) grade, pathological tumor node metastasis (pTNM) stage, venous tumor thrombus, and so on, were acquired. Univariate and multivariate Cox proportional hazards analyses were performed to identify the prognostic factors for disease-free survival (DFS)., Results: Of the 69 patients, 25 patients (36.2%) experienced disease progression during the follow-up period. In univariate analysis, the primary tumor size (>4.85 cm), pTNM stage (Ⅲ/Ⅳ), WHO/ISUP grade (G3/4), venous tumor thrombus, adjuvant therapy, SUVmax (>3.55), and TLR (>1.66) were found to correlate with the incidence of decreased DFS (P < 0.05). In multivariate analysis, TLR (P = 0.007, HR: 5.489, 95%CI: 1.605-18.774) and pTNM stage (P = 0.024, HR: 10.385, 95%CI: 1.361-79.238) were revealed to serve as independent prognostic predictors for DFS after adjustment for other variables. Only 3 cases (8.3%) with normal TLR showed disease progression, while 22 cases (66.7%) with elevated TLR experienced disease progression., Conclusion: ccRCC patients with preoperatively elevated TLR (>1.66) and high pTNM stages (Ⅲ/Ⅳ) had significantly unfavorable survival outcomes. These patients should be carefully monitored to detect the possibility of disease progression after nephrectomy as early as possible., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A 48-year-old woman presented with refractory oral ulcers and skin rashes on the palms and trunk, diagnosed as paraneoplastic pemphigus. The chest x-ray revealed a mass in the right lower chest, and the F-FDG PET/CT scan showed the lesion in the right anterior-inferior mediastinum with intense F-FDG uptake, accompanied by right parasternal adenopathy and pleural effusion. The surgical pathology proved a follicular dendritic cell sarcoma, with right parasternal lymph node metastasis.

Bilateral adrenal masses were found by ultrasound on a 55-year-old man with sudden onset of chest distress and palpitation after drinking alcohol. After the negative laboratory tests of plasma catecholamine and urinary vanillylmandelic acid, the F-FDG PET/CT revealed extremely intense metabolic activity in the bilateral adrenal lesions, and the subsequent I-meta-iodobenzylguanidine scintigraphy also showed increased radioactivity in the lesions. The pathology of surgery confirmed the diagnosis of bilateral pheochromocytomas.

A 41-year-old woman presented with irregular vaginal bleeding, and a vaginal tumor was found and proved to be a clear cell carcinoma by biopsy. An F-FDG PET/CT was performed to exclude its metastatic possibility, which showed the vaginal tumor was the only lesion with F-FDG avidity. The vaginectomy and hysterectomy were performed to resect the lesion, and primary clear cell carcinoma of the vagina was finally diagnosed.

An F-FDG PET/CT was performed on a 47-year-old man diagnosed as multiple myeloma with diffuse bone marrow infiltration on pathology. PET/CT findings presented as a pattern of skeletal "superscan," including diffuse and prominent hypermetabolism throughout the axial and proximal appendicular skeleton, which all alleviated after 5 cycles of chemotherapy.

An F-FDG PET/CT was performed on a 43-year-old woman with photosensitive skin rash, abnormal liver function, and pancytopenia, which demonstrated prominent hepatomegaly, splenomegaly, and diffuse liver F-FDG avidity. The liver biopsy revealed intrahepatic cholestasis with biliary fibrosis resulting from the deposition of protoporphyrin. X-linked erythroid-specific 5-aminolevulinate synthase gene analysis proved the diagnosis of X-linked protoporphyria.

Objective: To evaluate the potential clinical value of quantitative functional FDG PET and pathological amyloid-β PET with cerebrospinal fluid (CSF) biomarkers and clinical assessments in the prediction of Alzheimer’s disease (AD) progression. Methods: We studied 82 subjects for up to 96 months (median = 84 months) in a longitudinal Alzheimer’s Disease Neuroimaging Initiative (ADNI) project. All preprocessed PET images were spatially normalized to standard Montreal Neurologic Institute space. Regions of interest (ROI) were defined on MRI template, and standard uptake values ratios (SUVRs) to the cerebellum for FDG and amyloid-β PET were calculated. Predictive values of single and multiparametric PET biomarkers with and without clinical assessments and CSF biomarkers for AD progression were evaluated using receiver operating characteristic (ROC) analysis and logistic regression model. Results: The posterior precuneus and cingulate SUVRs were identified for both FDG and amyloid-β PET in predicating progression in normal controls (NCs) and subjects with mild cognitive impairment (MCI). FDG parietal and lateral temporal SUVRs were suggested for monitoring NCs and MCI group progression, respectively. 18F-AV45 global cortex attained (78.6%, 74.5%, 75.4%) (sensitivity, specificity, accuracy) in predicting NC progression, which is comparable to the 11C-PiB global cortex SUVR’s in predicting MCI to AD. A logistic regression model to combine FDG parietal and posterior precuneus SUVR and Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-Cog) Total Mod was identified in predicating NC progression with (80.0%, 94.9%, 93.9%) (sensitivity, specificity, accuracy). The selected model including FDG posterior cingulate SUVR, ADAS-Cog Total Mod, and Mini-Mental State Exam (MMSE) scores for predicating MCI to AD attained (96.4%, 81.2%, 83.6%) (sensitivity, specificity, accuracy). 11C-PiB medial temporal SUVR with MMSE significantly increased 11C-PiB PET AUC to 0.915 (p<0.05) in predicating MCI to AD with (77.8%, 90.4%, 88.5%) (sensitivity, specificity, accuracy). Conclusion: Quantitative FDG and 11C-PiB PET with clinical cognitive assessments significantly improved accuracy in the predication of AD progression. [ABSTRACT FROM AUTHOR]

Aim: To assess the potential of using preoperative 18F-FDG PET/CT to predict the prognosis of patients with clear cell renal cell carcinoma (ccRCC) after nephrectomy.Methods: Sixty-nine patients with newly diagnosed ccRCC who underwent 18F-FDG PET/CT prior to surgery were retrospectively reviewed. The metabolic parameters of maximum standardized uptake value (SUVmax) and tumor-to-liver ratio (TLR) from 18F-FDG PET/CT were obtained. Clinicopathological characteristics, including the World Health Organization/the International Society of Urological Pathology (WHO/ISUP) grade, pathological tumor node metastasis (pTNM) stage, venous tumor thrombus, and so on, were acquired. Univariate and multivariate Cox proportional hazards analyses were performed to identify the prognostic factors for disease-free survival (DFS).Results: Of the 69 patients, 25 patients (36.2%) experienced disease progression during the follow-up period. In univariate analysis, the primary tumor size (>4.85 cm), pTNM stage (Ⅲ/Ⅳ), WHO/ISUP grade (G3/4), venous tumor thrombus, adjuvant therapy, SUVmax (>3.55), and TLR (>1.66) were found to correlate with the incidence of decreased DFS (P < 0.05). In multivariate analysis, TLR (P = 0.007, HR: 5.489, 95%CI: 1.605-18.774) and pTNM stage (P = 0.024, HR: 10.385, 95%CI: 1.361-79.238) were revealed to serve as independent prognostic predictors for DFS after adjustment for other variables. Only 3 cases (8.3%) with normal TLR showed disease progression, while 22 cases (66.7%) with elevated TLR experienced disease progression.Conclusion: ccRCC patients with preoperatively elevated TLR (>1.66) and high pTNM stages (Ⅲ/Ⅳ) had significantly unfavorable survival outcomes. These patients should be carefully monitored to detect the possibility of disease progression after nephrectomy as early as possible. [ABSTRACT FROM AUTHOR]