Hueisch Jy Ding

Meta-analysis of the diagnostic performance of [18F]FDG-PET and PET/CT in renal cell carcinoma.

Abstract Objectives: Positron emission tomography (PET) using fluorodeoxyglucose (FDG) is useful for restaging renal cell carcinoma (RCC) and detecting metastatic diseases but is less satisfactory for detecting primary disease. We evaluated whether the integration of computed tomography (CT) scans with the PET system could increase the applicability of FDG-PET for RCC. Methods: The MEDLINE databases were searched for relevant studies published since 2001. Two reviewers independently assessed the methodological quality of each study identified. We then performed a meta-analysis of the sensitivity and specificity of FDG-PET findings as reported in all the selected studies. Results: Fourteen studies were eligible for inclusion. The pooled sensitivity and specificity of FDG-PET were 62% and 88% respectively, for renal lesions. For detecting extra-renal lesions, the pooled sensitivity and specificity of FDG-PET were 79% and 90%, respectively, based on the scans, and 84% and 91% based on the lesions. The use of a hybrid FDG-PET/CT to detect extra-renal lesions increased the pooled sensitivity and specificity to 91% and 88%, respectively, with good consistency. Conclusions: For RCC, combining the FDG-PET and CT systems is helpful for detecting extra-renal metastasis rather than renal lesions. The hybrid PET/CT system has comparable sensitivity and specificity with PET in detecting extra-renal lesions of RCC. Advances in knowledge: The FDG-PET and PET/CT systems are both useful for detecting extra-renal metastasis in renal cell carcinoma.

A systematic review and meta-analysis of pretherapeutic lymph node staging of colorectal cancer by 18F-FDG PET or PET/CT.

The purpose of the present study was to conduct a systematic review and meta-analysis of the published literature to evaluate the diagnostic performance of fluorine-18 2-fluoro-2-deoxy-D-glucose (18F-FDG) PET in the pretherapeutic assessment of nodal staging in patients with colorectal cancer (CRC). We conducted a systematic MEDLINE search of articles in the published literature (last update, February 2012). Two reviewers independently assessed the methodological quality of each study. We estimated pooled sensitivity, specificity, summary receiver operating characteristic curves, and summary likelihood ratios. A total of 409 patients from 10 studies were analyzed. The pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 18F-FDG PET [PET/computed tomography (CT)] in the detection of pretherapeutic lymph node involvement in patients with CRC were 42.9% [95% confidence interval (CI): 36.0–50.0%], 87.9% (95% CI: 82.6–92.0%), 2.82 (95% CI: 1.96–4.07), and 0.69 (95% CI: 0.62–0.78), respectively. There is no solid evidence to support the routine clinical application of 18F-FDG PET (PET/CT) in the pretherapeutic evaluation of lymph node status in patients with CRC. However, 18F-FDG PET (PET/CT) could be used to strengthen the possibility of suspected metastatic lymph nodes detected by other imaging modalities.

Potential value of dual-time-point 18F-FDG PET compared with initial single-time-point imaging in differentiating malignant from benign pulmonary nodules: A systematic review and meta-analysis

We performed a meta-analysis to assess the potential value of dual-time-point (DTP) imaging as compared with initial single-time-point (STP) scanning with 18F-fluorodeoxyglucose (18F-FDG) PET in differentiating malignant from benign single pulmonary nodules. Data on the performance of DTP 18F-FDG PET imaging in assessing lung nodules were extracted from articles of prospective or retrospective original research published between January 2001 and April 2010. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used to assess the quality of study methodology. Heterogeneity in the results of the studies was assessed, and summary receiver operating characteristic (SROC) curves were constructed. Eleven studies comprising a total of 788 patients who underwent initial scanning, 778 of whom also underwent DTP imaging, were included in the final analysis. The quality of study methodology was judged to be moderate. Substantial heterogeneity in the results of the studies, with inconsistency (I2) index values above 85%, reflected important differences in study methods and populations, including varying lesion sizes, 18F-FDG avidity, uptake interval for delayed imaging, and threshold for positive result on DTP imaging. SROC curve analysis revealed a statistically nonsignificant trend toward higher sensitivity with DTP imaging, at moderate levels of specificity, when compared with initial STP scanning. The area under the curve (SE) values for DTP and initial STP imaging were 0.839 (0.079) and 0.757 (0.074), respectively. Although the results of our analysis do not support the routine use of DTP imaging with 18F-FDG PET in the differential diagnosis of pulmonary nodules, this technique may provide additional information in selected cases with equivocal results from initial scanning. Further prospective research is required to better define the potential benefits of DTP 18F-FDG PET imaging.

Impact of age on FDG uptake in the liver on PET scan.

PURPOSE The intensity of physiological 18F-2-deoxy-D-glucose (FDG) uptake in the liver varies. It is important to be familiar with the varying degree of FDG accumulation in the liver that represents normal distribution and physiological changes, before attempting to interpret whole-body positron emission tomography (PET) imaging for malignancy detection. The aim of this study is to evaluate the possible factors influencing the intensity of physiological FDG uptake in the liver on FDG PET imaging. MATERIALS AND METHODS From 2005 to 2007, a total of 339 consecutive healthy subjects, referred from the Department of Community Medicine and Health Examination Center of our hospital for health screening, were retrospectively recruited for analysis. Demographic data were collected from chart records. Whole body FDG PET imaging and serologic determination of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection status were performed on all subjects. The mean and maximum standard uptake values (SUVs) of the liver were calculated. The relationships between sex, age, HBV and HCV infection status, and SUVmax and SUVmean of the liver on FDG PET imaging were evaluated. RESULTS There was no statistically significant relationship between sex, HBV and HCV infection status and maximum standard uptake value (SUVmax) or mean standard uptake value (SUVmean) of the liver. After adjusting for covariables, age was a statistically significant predictor of SUVmax (B=0.18; P= .001) and SUVmean (B=0.16; P= .004) of the liver on FDG PET imaging. CONCLUSION Age has a significant and positive impact on both maximum and mean standard uptake values of the liver on FDG PET imaging. High physiological background FDG uptake will reduce diagnostic sensitivity and accuracy for malignancy detection in the liver.

F-18 FDG PET in detecting uterine leiomyoma

PURPOSE Uterine leiomyoma, benign tumors of the human uterus, are clinically apparent in about 25% of women and the most common solid pelvic tumors. The purpose of this study was to investigate the F-18 2-fluoro-2-deoxy-D-glucose (FDG) uptake in the uterine leiomyoma and assess the correlation between the intensity of FDG uptake in the uterine leiomyomas and menstrual cycle. METHODS A total of 589 charts of healthy females examined by whole body FDG positron emission tomography (PET) for health screening examination were reviewed retrospectively. Twenty-two of them were suspected gynacecological tumors and referred to the department of gynacecology to ascertain the nature of the causes. Final diagnosis as uterine leiomyomas were made based on uterine sonography, pelvic computed tomography, or pelvic magnetic resonance imaging scans. We defined FDG uptake as Grade I when FDG uptake was less than liver uptake, Grade II when FDG uptake was equal to liver uptake, and Grade III when FDG uptake was greater than liver uptake. The menstrual cycle was recorded on the day of performing FDG PET in premenopausal women. RESULTS The FDG uptake in the uterine region is Grade I in three of these 22 females (13.65%), Grade II in 16 (72.7%), and Grade III in 3 (13.65%). CONCLUSION There is no significant correlation between the intensity of FDG uptake in the uterine leiomyomas and menstrual cycle (P=.914).

FDG PET or PET/CT in Evaluation of Renal Angiomyolipoma

Objective Angiomyolipoma is the most common benign kidney tumor. However, literature describing FDG PET findings on renal angiomyolipoma (AML) is limited. This study reports the FDG PET and PET/CT findings of 21 cases of renal AML. Materials and Methods The study reviews FDG PET and PET/CT images of 21 patients diagnosed with renal AML. The diagnosis is based on the classical appearance of an AML on CT scan with active surveillance for 6 months. The study is focused on the observation of clinical and radiographic features. Results Six men and 15 women were included in our study. The mean age of the patients was 57.14 ± 9.67 years old. The mean diameter of 21 renal AML on CT scans was 1.76 ± 1.00 cm (Min: 0.6 cm; Max: 4.4 cm). CT scans illustrated renal masses typical of AMLs, and the corresponding FDG PET scans showed minimal FDG activities in the area of the tumors. None of the 21 AMLs showed a maximum standardized uptake value (SUVmax) greater than 1.98. No statistically significant correlation was present between SUVmax and tumor size. Conclusion Renal AMLs demonstrate very low to low uptake on FDG PET and PET/CT imaging in this study. When a fat-containing tumor in the kidney is found on a CT scan, it is critical to differentiate an AML from a malignant tumor including an RCC, liposarcoma, and Wilms tumor. This study suggests that FDG PET or PET/CT imaging is useful for differentiating a renal AML from a fat-containing malignant tumor.

Pretreatment metabolic tumor volumes to predict the short-term outcome of unresectable locally advanced squamous cell carcinoma of the esophagus treated with definitive chemoradiotherapy

PurposeThe aim of the study was to investigate the predictive role of pretreatment metabolic tumor volume (MTV) in patients with squamous cell carcinoma of locally advanced esophageal cancer treated with definitive chemoradiotherapy. Patients and methodsNinety patients received pretreatment with 18F-fluorodeoxyglucose (18F-FDG) PET/CT, and two types of MTVs were measured on the basis of either a maximal standardized uptake value (SUVmax) of 2.5 (MTV2.5) or a fixed threshold of 20% (MTV20%). Overall survival (OS) and disease-free survival (DFS) were examined, and independent prognosticators were identified by Cox regression analysis. ResultsOn a median follow-up of 15 months, 51 patients were seen to have died because of tumor recurrence or other illnesses. Multivariate analysis of OS revealed that MTV20%>40 ml was the only predictor of outcome with a lower 1-year OS [P=0.003, hazard ratio (HR)=2.29, 95% confidence interval (CI) 1.36–3.91]. Two independent predictors of DFS were MTV20%>40 ml (P=0.02, HR=1.78, 95% CI 1.09–2.91) and stage IV disease (P=0.01, HR=1.84, 95% CI 1.12–3.03). ConclusionPretreatment MTV20% is a novel marker for OS and DFS in patients with unresectable locally advanced esophageal cancer treated with definitive chemoradiotherapy. Treatment intensification must be considered for patients with higher MTVs.

Positive correlation between serum liver enzyme levels and standard uptake values of liver on FDG-PET.

PURPOSE The aim of the study is to assess the relationship between serum liver enzyme level, hepatic virus infectious state, and standard uptake value of liver on 2-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET). MATERIAL AND METHODS It is the retrospective review study from September 2005 to September 2007. A total of 354 healthy subjects referred from the Department of Community Medicine and Health Examination Center of our hospital for health screening were reviewed retrospectively and recruited for analysis. Whole-body FDG-PET, serum liver enzyme levels [aspartate aminotransferase (AST) or SGOT and alanine aminotransferase (ALT) or SGPT], and hepatic B (HBV)/hepatic C virus (HCV) infectious states by checking serum antibodies were performed in all subjects. The mean and maximal values of standard uptake values (SUV) of liver were calculated. The relationships between serum liver enzyme levels, hepatic virus infectious states, and standard uptake values of liver on FDG-PET were evaluated. RESULT There is statistically significant positive correlation between SGOT/SGPT and SUV of liver on FDG-PET. However, there are no significant differences in the SUV of liver on FDG-PET between HBV/HCV infection and nonhepatic virus infection subjects. CONCLUSION High FDG uptake in the liver because of high level of SGOT/SGPT may lower the diagnostic sensitivity of hepatic malignant or infectious lesions on FDG-PET. For avoiding false-negative findings, careful evaluation of liver on FDG-PET and correlation with other clinical manifestations should be recommended in patients with high level of SGOT/SGPT. Nevertheless, neither HBV/HCV infectious states significantly influences on the SUV of liver on FDG-PET.

Positive correlation between standardized uptake values of FDG uptake in the stomach and the value of the C-13 urea breath test.

Purpose: The distribution of FDG uptake in the stomach is variable. Gastritis is one of the causes of elevated FDG uptake. Helicobacter pylori (HP) infection was found in approximately 80% of patients with peptic ulcer and 30% to 60% of symptomatic gastritis. The C-13 urea breath test (UBT) is one of the gold standard tools in diagnosis of HP infection. The aim of this study was to assess the correlation between standardized uptake values (SUVs) of FDG uptake in the stomach and the value of the C-13 urea breath test (UBT). Methods: Sixteen patients, referred from the department of community medicine, for FDG PET for health examination were chronologically enrolled for detection of HP infection by using the C-13 UBT within 1 week. The maximal SUVs of FDG uptake in the gastric wall as well as the value of the C-13 UBT were measured. The correlation between maximal SUVs of FDG uptake in the stomach and the value of the C-13 UBT was observed. Results: We took the results of C-13 UBT as the final diagnosis of HP infection. Of 16 patients, 5 were HP-infected and 11 were uninfected. Standardized uptake values of FDG uptake in the gastric wall were strong positively correlated with the value of the C-13 UBT in this retrospective study (P < 0.001). Conclusion: Except for gastric cancer, HP infection has to be concerned when high SUVs of FDG uptake in the stomach are noted.

Detection of gastroesophageal reflux esophagitis using 2-fluoro-2-deoxy-d-glucose positron emission tomography.

Background. Gastroesophageal reflux disease (GERD) is a common disease and a major upper gastrointestinal problem. The purpose of the present study is to evaluate the use of noninvasive 2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) to detect gastroesophageal reflux esophagitis. Materials and Methods. This is a retrospective study reviewing 408 healthy check-up subjects (169 females and 239 men), who underwent both FDG-PET and upper gastrointestinal endoscopy during September 2008 to December 2009. Quantitative analysis of FDG uptake in the distal part of the esophagus was performed by calculating the maximum standard uptake value (SUVmax). This indicated the degree of esophagitis. FDG-PET findings were compared with endoscopic (modified version of the Los Angeles classification) diagnoses as the gold standard. Results. The SUVmax ranged from 1.30 to 3.40 in normal subjects and from 1.30 to 4.00 in subjects with gastroesophageal reflux esophagitis. In the esophagitis group, the SUVmax was 2.13 ± 0.42 in subjects with modified LA grade M, 2.21 ± 0.45 in subjects with LA grade A, and 2.48 ± 0.44 in subjects with LA grade B and C gastroesophageal reflux esophagitis. One-way ANOVA and post-hoc comparison with Bonferroni correction (P value = 0.003) identified statistical differences between the three groups. Conclusion. Noninvasive FDG-PET may be useful in the detection and evaluation of various degrees of gastroesophageal reflux esophagitis.