Primary Tumor Fluorine-18 Fluorodeoxydglucose (18F-FDG) Is Associated With Cancer-Associated Weight Loss in Non-Small Cell Lung Cancer (NSCLC) and Portends Worse Survival.

Aim: To investigate the diagnostic potential of and associations between tumor 18F-FDG uptake on PET imaging and cancer-associated weight loss. Methods: 774 non-small cell lung cancer (NSCLC) patients with pre-treatment PET evaluated between 2006 and 2014 were identified. Using the international validated definition of cachexia, the presence of clinically significant pretreatment cancer-associated weight loss (WL) was retrospectively determined. Maximum Standardized Uptake Value (SUVMax) of 18F-FDG was recorded and dichotomized based on 3 experimental cutpoints for survival analyses. Each SUVMax cutpoint prioritized either survival differences, total cohort comparison sample sizes, or sample size by stage. Patient outcomes and associations between SUVMax and cancer-associated weight loss were assessed by multivariate, categorical, and survival analyses. Results: Patients were found to have an increased likelihood of having WL at diagnosis associated with increasing primary tumor SUVMax after controlling for potentially confounding patient and tumor characteristics on multivariate logistic regression (OR 1.038; 95% CI: 1.012, 1.064; P=0.0037). After stratifying the cohort by WL and dichotomized SUVMax, both factors were found to be relevant in predicting survival outcomes when the alternative variable was constant. Of note, the most striking survival differences contributed by WL status occurred in high SUVMax groups, where the presence of WL predicted a median survival time detriment of up to 10 months, significant regardless of cutpoint determination method applied to categorize high SUVMax patients. SUVMax classification was found to be most consistently relevant in both WL and no WL groups. Conclusions: The significant positive association between significant pretreatment cancer-associated weight loss and primary tumor SUVMax underscores increased glucose uptake as a component of catabolic tumor phenotypes. This substantiates 18F-FDG PET analysis as a prospective tool for assessment of cancer-associated weight loss and corresponding survival outcomes. Furthermore, the survival differences observed between WL groups across multiple SUVMax classifications supports the importance of weight loss monitoring in oncologic workups. Weight loss in the setting of NSCLCs with higher metabolic activity as determined by 18F-FDG PET signal should encourage more aggressive and earlier palliative care interventions.

Quantifying the contribution of 18F-FDG PET to the diagnostic assessment of pediatric patients with fever of unknown origin: a systematic review and meta-analysis.

BACKGROUND: The value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the diagnostic assessment of pediatric fever of unknown origin is not known, and evidence from adults is not applicable. OBJECTIVE: To quantify the contribution of 18F-FDG PET to pediatric fever of unknown origin, considering its diagnostic limitations. MATERIALS AND METHODS: We searched PubMed, EMBASE and Cochrane Central Register of Controlled Trials up to Feb. 18, 2021. We included studies on patients with pediatric fever of unknown origin presenting sufficient data to calculate the likelihood of achieving definite diagnosis (based on pathology or clinical follow-up) between those with abnormal PET findings versus those with normal PET findings. We assessed the risk of bias using a modified Newcastle-Ottawa quality assessment scale and quantified the value of PET by pooling the likelihood of achieving definite diagnosis using a random-effects model. RESULTS: We included 6 studies and found that pediatric patients with abnormal PET findings were about 17 times more likely to achieve definite diagnoses than those with normal PET findings (odds ratio [OR]: 16.75, 95% confidence interval [CI] 8.0-35, P < 0.00001). Sensitivity analyses using a fixed-effect model (OR 16.91, 95% CI 8.1-35, P < 0.0001) or removing one study at a time (OR 12-20, 95% CI lower bound 3.8-8.6, 95% CI upper bound 33-45, P < 0.0001) did not significantly alter the results. Sample size (interaction P = 0.75), imaging modality (interaction P = 0.29), length of follow-up (interaction P = 0.37), fever of unknown origin subclasses (interaction P = 0.89) and geographical areas (interaction P = 0.74) of studies showed no statistically significant influence on the results. CONCLUSION: 18F-FDG PET is a promising approach in the diagnostic work-up of pediatric fever of unknown origin. Further studies are warranted to support routine use in clinical care.

AuntMinnie Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Leads to Diagnosis of Immunoglobulin G4-Related Disease.

A 61-year-old male underwent fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) for evaluation of fever and weight loss with clinical suspicion of occult malignancy or tuberculosis. The scan showed hypermetabolism in bilateral submandibular salivary glands, biliary radicles, pancreas, bilateral kidneys, prostate, and multiple lymph nodes. Based on the concomitant involvement of these sites, suspicion of immunoglobulin G4 (IgG4)-related disease was raised in PET-CT report. Further evaluation with serum IgG4 levels and histopathology of the submandibular salivary gland confirmed the diagnosis of IgG4-related disease. The ability of FDG PET-CT to evaluate the whole-body status of disease played a crucial role in this case.

Ultrafast Ultrasound Imaging for Super-Resolution Preclinical Cardiac PET.

PURPOSE: Physiological motion and partial volume effect (PVE) significantly degrade the quality of cardiac positron emission tomography (PET) images in the fast-beating hearts of rodents. Several Super-resolution (SR) techniques using a priori anatomical information have been proposed to correct motion and PVE in PET images. Ultrasound is ideally suited to capture real-time high-resolution cine images of rodent hearts. Here, we evaluated an ultrasound-based SR method using simultaneously acquired and co-registered PET-CT-Ultrafast Ultrasound Imaging (UUI) of the beating heart in closed-chest rodents. PROCEDURES: The method was tested with numerical and animal data (n = 2) acquired with the non-invasive hybrid imaging system PETRUS that acquires simultaneously PET, CT, and UUI. RESULTS: We showed that ultrasound-based SR drastically enhances the quality of PET images of the beating rodent heart. For the simulations, the deviations between expected and mean reconstructed values were 2 % after applying SR. For the experimental data, when using Ultrasound-based SR correction, contrast was improved by a factor of two, signal-to-noise ratio by 11 %, and spatial resolution by 56 % (~ 0.88 mm) with respect to static PET. As a consequence, the metabolic defect following an acute cardiac ischemia was delineated with much higher anatomical precision. CONCLUSIONS: Our results provided a proof-of-concept that image quality of cardiac PET in fast-beating rodent hearts can be significantly improved by ultrasound-based SR, a portable low-cost technique. Improved PET imaging of the rodent heart may allow new explorations of physiological and pathological situations related with cardiac metabolism.

18 F-FDG PET/CT imaging of small intestinal metastasis from pulmonary sarcomatoid carcinoma: Brief report and review of the literature.

We herein report two cases of small intestinal metastasis from pulmonary sarcomatoid carcinoma (PSC) detected by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT). We reviewed the literature on 18 F-FDG PET/CT features in gastrointestinal metastasis of PSC patients since 1992, and further analyzed the imaging features. According to the literature review, 23 eligible cases were identified from eight studies, and no cases underwent 18 F-FDG PET/CT imaging. In this study, clinical and PET/CT imaging data of two patients are reported. In our cases, clinical and the CT images of lung masses were not typical, but the uptake of 18 F-FDG was remarkably high, with SUVmax exceeding 30. Small intestinal metastases may not be related to obstruction, or even the local intestinal cavity may be dilated. Therefore, in PSC patients with mild or without abdominal symptoms, 18 F-FDG PET/CT imaging could identify intestinal metastasis at a relatively early stage and may be used to determine the preferred biopsy site, or early intervention by surgery. KEY POINTS: 18 F-FDG PET/CT imaging of small intestinal metastasis of PSC has not been previously reported in the literature and here we report the 18 F-FDG PET/CT features of two cases. The uptake of 18 F-FDG was remarkably high in both the primary tumor and metastatic intestinal lesion. 18 F-FDG PET/CT imaging may therefore be used to determine the preferred biopsy site or early intervention by surgery.

Manifestation of medullary thyroid carcinoma on 18F-FDG PET/CT / 天津医药

Objective To investigate the 18F-FDG PET/CT features of medullary thyroid carcinoma (MTC), and to improve its diagnosis preoperatively.Methods Data of 18F-FDG PET/CT findings and clinical materials of 7 patients with MTC confirmed by pathology were retrospectively analyzed. SUVmaxEand SUVmaxDwere measured in primary tumor, and retention index(RI)was calculated.Results There were four patients with single lesion,two patients with double lesions, one patient with multiple lesions,four patients with lesions of irregular shape,four patients with lesions of unclear border, seven patients with lesions of uneven decreased density and five patients with calcifications in lesions.Uptake of 18F-FDG in primary tumor was lower in 2 patients,their SUVmaxEvalues were 2.5 and 2.1 respectively,and RI values were-20% and-14.3% respectively.The other five patients showed higher metabolism in both early and delayed imaging,and SUVmaxEwas 3.6-9.1 with an average of 5.8±2.1.RI was 7.5%-45.8% with the average of 21.3%±16.2%.There were five patients with cervical lymph node metastasis.The high metabolism was found in both early and delayed imaging of FDG.The ranges of SUVmaxEand SUVmaxDwere 3.2-8.2 and 3.3-9.8 respectively.None of 7 patients showed distant metastasis.Conclusion 18F-FDG PET/CT is helpful for identifying MTC and providing information about biological behavior and evaluating metastasis of MTC.

The clinical value of 18F-FDG PET/CT for diagnosing tumor in physical examination people with unexplained elevated serum CEA / 天津医药

Objective To evaluate the clinical value of 18F-FDG PET/CT for detecting tumor on physical examination people with unexplained elevated serum carcinoembryonic antigen (CEA). Methods A total of 100 physical examination people with unexplained elevated serum levels of CEA in our hospital from June 2010 to December 2014 were involved in the study. All the people were detected with 18F-FDG PET/CT. The pathology, clinical follow ups and conventional medical imaging results were combined to evaluate the value of 18F-FDG PET/CT in diagnosing tumor. The doubling time (DT) of CEA was calculated in the patients who were received more than twice of serum CEA detection. The relationships between serum CEA levels, CEA DT and 18F-FDG PET/CT imaging were analyzed. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of serum CEA. Results Twenty-seven patients were confirmed with malignant tumor, and the rest of 73 cases were excluded. The 18F-FDG PET/CT reported one false positive and one false negative respectively. The sensitivity, specificity, accuracy, positive and negative predictive values of 18F-FDG PET/CT in diagnosing malignant tumors were 96.3%, 98.6%, 98.0%, 96.3% and 98.6% respectively. The median serum CEA levels were significantly higher in the positive 18F-FDG PET/CT patients than those in the negative patients (Z=5.796, P180 d and DT180 d and patients with DT0.05). The area under the curve (AUC) of serum CEA was 0.894, the optimal diagnostic cutoff value was 14.24μg/L. Conclusion 18F-FDG PET/CT is a useful image modality for detecting malignant tumors in patients with unexplained elevated serum CEA, especially for patients with CEA≥14.24μg/L and increase progressively.

Manejo exitoso de infección de injerto vascular: rol del 18 fluorodeoxyglucose positron emission tomography/computed tomography / Successful management of vascular graft infection: The role of 18fluorodeoxyglucose positron emission tomography/computed tomography

La opción de un injerto vascular es una medida correctiva para pacientes con enfermedad arterial periférica o aneurismas y para acceso arteriovenoso en pacientes con hemodiálisis crónica. A partir de la colocación de una prótesis de injerto vascular se puede desarrollar infección asociada en el 1-6% de los pacientes, con una alta incidencia de mortalidad del 13 al 58%. El diagnóstico de una infección asociada a injerto vascular se realiza a partir de hallazgos clínicos, microbiológicos e imagenológicos, para así definir, además de su presencia, su compromiso y extensión. El manejo ideal requiere de tratamiento quirúrgico y antibioticoterapia; sin embargo, el tratamiento quirúrgico no siempre es posible. Reportamos este caso de manejo médico exitoso de una infección de injerto vascular de aorta en la cual el 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) presentó utilidad como método diagnóstico y de seguimiento.

The option of a vascular graft is a corrective intervention for patients with peripheral artery disease, aneurisms, and to achieve arterio-venous access in patients on chronic hemodialysis. Infections from a prosthetic vascular graft occurs in 1 to 6% of patients, and this development is related to the incidence of mortality of 13 to 58%. The diagnosis of a vascular graft infection is made via the combination of clinical, microbiologic and imaging findings that allow a definition of not only the presence of infection but also its severity and spread. The ideal approach requires both surgical and antimicrobial therapy; however, the former is not always possible. We report a case of successful medical management of an aortic vascular graft infection and the usefulness of a 18F-fluorodeoxyglucose positron emission tomography/computedtomography (18F-FDG-PET/CT) scan as a tool for diagnosis and follow-up.

Clinical Significance of 18F-FDG PET/CT in the Etiological Diagnosis of Postoperative Intestinal Obstruction in Patients with Gastrointestinal Cancer / 中国医科大学学报

Objective To explore the significance of 18fluorodeoxyglucose positron emission tomography(18F?FDG PET/CT)in the etiological diag?nosis of postoperative intestinal obstruction in patients with gastrointestinal cancer. Methods A total of 51 patients with postoperative intestinal ob?struction undergone 18F?FDG PET/CT were enrolled for the study. The images were interpreted by visual and semi?quantitative analysis(maximum standard uptake value,SUVmax). All the cases were confirmed by pathology and clinical follow?up for more than half a year. The sensitivity,specifici?ty and accuracy of 18F?FDG PET/CT for detecting malignant intestinal obstruction were calculated. Results Of the 51 patients,35 cases were con?firmed for malignant intestinal obstruction,and 16 cases were caused by other benign diseases. 18F?FDG PET/CT imaging was positive in 36 cases, and 33 cases were diagnosed as malignant and recurrent intestinal obstruction. Three cases of PET false?positive were peritonitis adhesion and anasto?motic inflammation. Two cases of PET false negative were peritoneal micrometastasis. The SUVmax of malignant lesions was 8.86±4.82,and the SUVmax of benign lesions was 2.05±1.95. The uptake of FDG was significantly higher in malignant intestinal obstruction than in benign intestinal obstruction (t=7.15,P<0.01). The sensitivity,specificity,and accuracy of 18F?FDG PET/CT diagnosis of malignant lesion were 94.3%,81.3%,and 90.2%, respectively. Conclusion The uptake of 18F?FDG in malignant intestinal obstruction was higher than that in benign intestinal obstruction. 18F?FDG PET/CT have a good diagnostic value for the intestinal obstruction of postoperative gastrointestinal cancer.

Impact of three threshold segmentation of 18FDG PET image on target volume delineation and radiotherapy treatment planning of non-small cell lung cancer / 中华放射肿瘤学杂志

Objective To evaluate the accuracy, of different threshold segmentation of 18FDG PET for target volume delineation of non-small cell lung cancer(NSCLC) and the potential influence on radiotherapy treatment planning. Methods Eight NSCLC patients who had tumor with clear margin on CT scan and the amplitude of tumor movements not more than 5 mm were enrolled. PET scans were carried out at 1 h after intravenous injection of 18FDG with CT image for attenuation revisement. Gross target volume (GTV) delineated on CT image ( GTVCT ) was used as the standard. Then, GTVs were delineated on PET image with three different threshold segmentation of 42% Imax(total) (42% of maximum voxel intensity within the tumor) ,Iback + 20% Imax-back(max) (mean background intensity + 20% of normalized background-subtracted maximum voxel intensity within the tumor) and Iback -20% Imax-back(slice) (mean background intensity + 20% of normalized background-subtracted maximum voxel intensity of each slice within the tumor) ,the corresponding GTV was named as GTV42%, GTV20%max and GTV20%slice. Both the size of GTV42%, GTV20%max, GTV20%slice and GTVCT,and the coverage over GTVCT for each GTV were compared. A three dimensional margin of 1 cm were added to GTVCT, GTV42%, GTV20%max and GTV20%slice to form corresponding PTVCT, PTV42%, PTV20%max and PTV20%slic e. Three dimensional conformal radiotherapy treatment plans were designed based on PTVCT,PTV42% , PTV20%max and PTV20%slice respectively for each patient. The prescription dose of all PTVs was 66 Gy in 33 fractions in 6.6 weeks. Both the volume accepting dose less than 95% of prescription dose within PTVCT ( VPTV ) and the lung V20 were compared among the four plans based on different PTVs. Tumor control probability(TCP) as well as lung normal tissue complication probability (NTCP) were also compared. Resuits Eight patients were enrolled in this study. Median deviation of volume between GTVPET and GTVCT were -54.1% , -21.5 % and 5.3 % for GTV42% , GTV20%max and GTV20%slice, respectively. Median coverage over GTVCT of GTV42% , GTV20%max and GTV20%slice was 45.9% ,78.0% and 95.3% respectively( F = 57.50,P＜0.01). Median 7.5% of VPTV was observed for radiotherapy treatment plan based on PTV42% ,which meant that it might induce median 1% decrease of TCP comparing with that of radiotherapy treatment plan based on PTVCT. Whereas,there were only 1.3% and 0.0% of VPTV for treatment plans based on PTV20%max and PTV20%slice respectively. As far as TCP was concemed, both PTV20%max group and PTV20%slice group were superior to PTV42% group,there was no significant difference among PTV20%max group, PTV20%slice group and PTVCT group. Lung V20 and lung NTCP showed no significant difference among all groups. Conclusions The threshold segmentation of Iback + 20% Imax-back(slice) , being slice specialized, might be an optimal threshold segmentation for target volume delineation of lung caner. Independent of information of target volume provided by CT scan in advance,it is recommended to use for the target volume delineation of NSCLC with atelectasis.