Diagnostic Accuracy Of 18F-FDG Research Articles

Advantage of PET/CT in Target Delineation of MRI-negative Cervical Lymph Nodes In Intensity-Modulated Radiation Therapy Planning for Nasopharyngeal Carcinoma.

Introduction: In intensity-modulated radiation therapy (IMRT) planning for nasopharyngeal carcinoma (NPC), cervical lymph nodes (CLNs) that appear negative on magnetic resonance imaging (MRI) scans can be difficult to target. The purpose of this study was to assess the advantage of 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) for distinguishing MRI-negative CLNs and the effect of 18F-FDG PET/CT on diagnosis, target delineation, and dose prescription in IMRT planning for NPC.Methods: Thirty-five NPC patients with 37 MRI-negative CLNs underwent 18F-FDG PET/CT imaging before treatment. Ultrasonography-guided fine-needle aspiration cytology (USgFNAC) was performed to examine the pathology of CLNs. The 18F-FDG PET/CT and cytopathological results were compared, and the diagnostic accuracy of 18F-FDG PET/CT was calculated. The cytopathologically confirmed CLNs were delineated and treated as the gross tumor volume of lymph nodes (denoted as GTVnd).Results: Nineteen of the 37 MRI-negative CLNs were positive on 18F-FDG PET/CT, and metastasis was confirmed by USgFNAC in 16 CLNs. Of the remaining 18 18F-FDG PET/CT-negative lymph nodes, metastasis was confirmed in one. The diagnostic accuracy, sensitivity, and specificity of 18F-FDG PET/CT were 89.2%, 94.1%, and 85.0%, respectively. The positive and negative predictive values were 84.2% and 94.4%, respectively. With a median follow-up of 48.3 months, no relapse was observed among the 18F-FDG PET/CT-positive CLNs with metastasis confirmed by USgFNAC and treated as GTVnd.Conclusion: 18F-FDG PET/CT had high accuracy, sensitivity, and specificity for distinguishing MRI-negative CLNs. 18F-FDG PET/CT-positive CLNs could reasonably be categorized as high-risk clinical tumor volume in IMRT planning for NPC.

Diagnostic accuracy of 18F-FDG PET/CT for detecting synchronous advanced colorectal neoplasia in patients with gastric cancer.

Preoperative screening for synchronous colorectal neoplasia (CRN) has been recommended in patients with gastric cancer because patients with gastric cancer are at increased risk for synchronous CRN. The aim of this study was to investigate the diagnostic accuracy of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for detecting synchronous advanced CRN in patients with gastric cancer.A total of 256 patients who underwent colonoscopy and 18F-FDG PET/CT for preoperative staging were enrolled in this study. The diagnosis of focal colonic 18F-FDG uptake on 18F-FDG PET/CT image was made based on histopathologic results from the colonoscopic biopsy. The 18F-FDG PET/CT result was considered as true positive for advanced CRN when focal 18F-FDG uptake matched colorectal carcinoma or adenoma with high-grade dysplasia in the same location on colonoscopy.Synchronous advanced CRN was detected in 21 of the 256 patients (4.7%). Sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 76.2%, 96.2%, and 94.5%. The size of CRN with a true positive result was significantly larger than that with a false negative result.18F-FDG PET/CT demonstrated high diagnostic accuracy for detecting synchronous advanced CRN in patients with gastric cancer. Colonoscopy is recommended as the next diagnostic step for further evaluation of a positive 18F-FDG PET/CT result in patients with gastric cancer.

The role of early 18F-FDG PET/CT in therapeutic management and ongoing risk stratification of high/intermediate-risk thyroid carcinoma.

Little is known about the role in ongoing risk stratification of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) performed early after radioactive iodine (RAI) ablation in differentiated thyroid carcinoma (DTC). The aim of the study is to investigate whether 18F-FDG PET/CT performed early after RAI ablation is useful to detect disease and to influence therapy and ongoing risk stratification. Patients with high/intermediate risk of recurrent DTC were included. 18F-FDG PET/CT scan was performed within 6 months after RAI ablation. We confirmed results with other imaging techniques, pathology reports, or follow-up. We classified the patient response as excellent, acceptable, or incomplete. Modified Hicks criteria were used to evaluate clinical impact. We included 81 patients with high/intermediate risk of recurrent DTC. Forty-one (50.6%) had positive uptake in 18F-FDG PET/CT, with negative (131)I whole-body scan ((131)I WBS). Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT were 92.5, 90.2, and 91.4%, respectively. 18F-FDG PET/CT results had an impact on therapy in 38.3% of patients. One year after initial therapy, 45.7% showed excellent response, 8.6% acceptable response, and 45.7% incomplete response. A statistically significant relationship was found between negative 18F-FDG PET/CT and excellent response (80 vs. 12.2%, p < 0.001; OR 52.8). 18F-FDG PET/CT scan performed early in surveillance of patients with high/intermediate-risk thyroid carcinoma provides important additional information not available with conventional follow-up methods and had a high impact on therapy. A negative 18F-FDG PET/CT predicts an excellent response to therapy in the new ongoing risk stratification.

NI-69 * UTILITY OF 18F-FDG PET/MR IN DIFFERENTIATION OF RECURRENT HIGH-GRADE GLIOMA FROM DELAYED RADIATION TISSUE INJURY: COMPARISON OF PET/CT TO PET/MR

PURPOSE: In a prior study of malignant brain tumors, we found 18F-FDG PET/MR to be superior to 18F-FDG PET/CT for distinguishing between progressive disease (PD) and radiation change (RC) (unpublished data). The purpose of this study is to compare the diagnostic accuracy of 18F-FDG PET/CT vs. 18F-FDG PET/MR in differentiating PD from RC in a subpopulation of malignant gliomas. METHODS: We evaluated 10 patients with high-grade gliomas whom had previously undergone chemoradiation therapy and developed MR evidence of PD per RANO criteria. All patients underwent 18F-FDG PET/CT, 18F-FDG PET/MR (MR attenuation correction, PET/MRAC), and conventional diagnostic MR (PET/MRD). pMR was also performed. Separate consensus blinded readings by two fellowship-trained radiologists (1 neuroradiology; 1 nuclear) were performed to assess the diagnostic efficacy of PET/CT, PET/MRAC, and PET/MRD. A qualitative subjective rating was given to each lesion (1 = definite RC; 2 = probable RC; 3 = equivocal; 4 = probable PD; 5 = definite PD). Sensitivity, specificity, and accuracy were determined for the three interpretation sessions after binary reclassification, with a rating of 1-3 defined as RC and 4-5 defined as PD. Wilcoxon-rank test was used for rating comparison between the three interpretations. RESULTS: PET/CT yielded sensitivity, specificity, and accuracy of 0.78, 1.00, and 0.80, respectively. Both PET/MRAC and PET/MRD demonstrated a sensitivity, specificity, and accuracy of 1.00, 1.00, and 1.00. There was no statistically significant difference in interpretation between PET/CT, PET/MRAC or PET/MRD. CONCLUSION: In this small series, 18F-FDG PET/MR utilizing either diagnostic or attenuation-only MR sequences had higher sensitivity and overall accuracy in delineating progressive disease from radiation change in glioma patients compared to 18F-FDG PET/CT. However, the difference was not statistically significant. A larger series is in progress to increase the power of the study in interpretation between 18F-FDG PET/MR and 18F-FDG PET/CT.

Diagnostic accuracy of 18F-FDG PET/CT for detection of advanced colorectal adenoma

To determine the accuracy of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) in the detection of advanced colorectal adenomas. In this retrospective study, patient consent was waived by the institutional review board. Combined FDG whole-body PET and computed tomography (CT) images (2000-2009) were re-read and compared with reports of complete colonoscopy performed up to 1 year after the PET examination. One or more areas of focal colonic uptake greater than the background indicated a positive PET result, irrespective of standardized uptake value (SUV). Lesion and patient-level measures of PET accuracy with their 95% confidence intervals (CI) were calculated. One hundred and eighty patients undergoing colonoscopy with or without biopsy underwent PET within 1 year prior to colonoscopy. There were 92 women and 88 men (mean age 63.3 years). Indications for PET were extent of disease and treatment response in all cases. Patients had non-colorectal cancer (n = 160) or colon cancer (n = 20). One hundred and fourteen FDG-avid lesions were present. In 33, there was no colonoscopic correlate. Two hundred and fifty-eight biopsies revealed tubular adenomas (n = 91, one with intra-mucosal cancer), tubulovillous adenomas (n = 28), adenocarcinoma (n = 37), inflammation (n = 22), hyperplastic polyps (n = 54), serrated adenoma (n = 5), metastatic disease (n = 5), normal/benign mucosa or submucosal benign tumors (n = 13) or miscellaneous (n = 3). Per-lesion performance of PET showed a sensitivity of 38% (95% CI: 31-46; 64/167) for all adenomas and carcinomas and 58% (95% CI: 49-67; 57/98) for lesions ≥ 10 mm. At the patient level, for all adenomas and carcinomas the sensitivity was 54% (95% CI: 44-63; 61/113), specificity 100% (pre-defined), positive predictive value (PPV) 100% (pre-defined), and negative predictive value (NPV) 56% (95% CI: 47-65; 67/119). For patients with advanced adenoma, PET sensitivity was 49% (95% CI: 35-63; 26/53) specificity, 100%, PPV 100% and NPV 82% (95% CI: 76-88; 127/154). Five of 37 adenocarcinomas were not detected, one of which was mucinous at histology. FDG PET detected most cancers, but only identified one-half of patients harbouring advanced adenomas. Based on the data, PET cannot be relied upon to accurately identify patients with advanced adenoma.

Diagnostic accuracy of 18F-FDG PET/CT for detection of suspected recurrence in patients with oesophageal carcinoma

To evaluate the role of (18)F-FDG PET/CT in the detection of recurrence in patients with oesophageal carcinoma, suspected clinically or following conventional investigations. This was a retrospective study. Data from 180 patients (age 56.3 ± 10.4 years; 126 men, 54 women) with histopathologically proven oesophageal carcinoma (squamous cell 115, adenocarcinoma 59, neuroendocrine carcinoma 4, small cell 1, poorly differentiated 1) who had undergone 227 (18)F-FDG PET/CT studies for suspected recurrence were analysed. Recurrence was suspected clinically or following conventional investigations. PET/CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local, nodal and distant recurrence. Results were compared to those from contrast-enhanced (CE) CT when available (109 patients). Clinical/imaging follow-up (minimum 6 months) with histopathology (when available) was taken as the reference standard. Of the 227 (18)F-FDG PET/CT studies,166 were positive and 61 were negative for recurrent disease. PET/CT showed local recurrence in 134, nodal recurrence in 115 and distant recurrence in 47, with more than one site of recurrence in 34. The PET/CT findings were true-positive in 153 studies, true-negative in 54, false-positive in 13 and false-negative in 7. The sensitivity of (18)F-FDG PET/CT was 96%, the specificity was 81%, the positive and negative predictive values were 92% and 89%, respectively, and the accuracy was 91%. PET/CT showed similar accuracy in patients with squamous cell carcinoma and in those with adenocarcinoma (P = 0.181).(18)F-FDG PET/CT was more specific than CECT (67% vs. 21%; P < 0.0001). PET/CT was superior to CECT for the detection of nodal recurrence (P < 0.0001), but not local recurrence (P = 0.093) or distant metastases (P = 0.441). (18)F-FDG PET/CT shows high accuracy in the detection of suspected recurrence in patients with oesophageal carcinoma. It is more specific than and is superior to CECT in the detection of nodal recurrence.

Diagnostic Accuracy of 18F-FDG PET/CT in Detection of Local Recurrence in Rectal Cancer and the Added Value of Dual Time Point Scanning

Objectives: To assess diagnostic accuracyof FDG PET/CT and the added value ofdual time point PET/CT (DTP) in detectionof local recurrence (LR) in patients withrectal cancer (RC). Methods: Patients (n =50, 41 males and 9 female, mean age 52 ±11 years). All patients underwent resection± chemotherapy and/or radiotherapy. 37patients were suspicious for LR on contrastenhanced CT (ce CT). All patientsunderwent whole body FDG PET/CT scan.In 18 patients 2 hours delayed pelvicPET/CT images were done. SUVmax cutoff of 3.0 was set to differentiate benignfrom malignant lesions based on ROCanalysis. Suspicious pelvic lesions werecorrelated with biopsies in 28 patients(56%) and with clinical and/or imagingfollow-up (FDG PET/CT, CT or MRI) in22 patients (44%). Sensitivity, specificity,positive and negative predictive values, andaccuracy in detection of LR using ce CTdata and following PET/CT werecalculated. Results: Nine patients had LR(18%). SUV max was higher in all patientswith LR. Sensitivity specificity, PPV,NPV, and accuracy for detecting recurrentlesions were significantly higher forPET/CT and PET/CT with tumor markersversus ce CT (p 0) in 4/18 patients withconfirmed LR (true positive) and revealedincrease in delayed SUV max (ΔSUV max>0) 4/18 with no evidences of LR (falsepositive) while 10/18 showed decrease inSUV max (ΔSUV max ≤0) in delayedimages with confirmed no LR (truenegative). The combined early SUVmaxand delayed increase in SUVmax revealedimprovement in overall accuracy comparedto either parameter alone. Conclusions:PET/CT has an excellent sensitivity and ahigher overall accuracy for detection oflocal rectal cancer recurrence whencompared to ce CT. Delayed PET/CT whenperformed is capable of improving thespecificity, PPV and accuracy of thePET/CT study.

Diagnostic accuracy of 18F-FDG PET/CT for assessing response to radiofrequency ablation treatment in lung metastases: a multicentre prospective study

To assess diagnostic accuracy of (18)F-FDG PET/CT at 3 months for the detection of local recurrence after radiofrequency ablation (RFA) of lung metastases. The PET/CT scan at 3 months was compared with a baseline PET/CT scan from a maximum of 2 months before RFA, with the reference standard as recurrence diagnosed by CT during a 12-month follow-up. Local recurrence was diagnosed on the PET/CT scan if lesional uptake was greater than the mediastinal background. Maximum standardized uptake values (SUVmax) were recorded. ROC curve analysis for SUVmax was performed. Overall survival (OS) and time to local relapse were computed from the date of RFA using the Kaplan-Meier method (www.clinicaltrials.gov: NCT 00382252). Between 2005 and 2009, 89 patients (mean age 65 years) underwent RFA for 115 lung metastases (mean size 16.2 ± 6.9 mm). The median SUVmax before RFA was 5.8 ± 4. PET/CT at 3 months and the reference standard were available in 77 patients and 100 lesions. Accuracy was 66.00% (95% CI 55.85-75.18%), sensitivity 90.91% (95 % CI 58.72-99.77 %), specificity 62.92% (95% CI 52.03-72.93%), PPV 23.26% (95% CI 11.76-38.63%), and NPV 98.25% (95% CI 90.61-99.96%). One-year OS was 94.2% (95% CI 86.6-97.5%) and the probability of being free of local recurrence 1 year after RFA was 84.6% (95% CI 75.0-90.8%). The specificity of PET/CT at 3 months is low because of persistent inflammation, especially when the lesion is close to the pleura. This technique is useful for its negative predictive value, but positive findings need to be confirmed by histology before new treatment is planned.

Diagnostic accuracy of 18F-FDG PET/CT for detecting recurrence in patients with primary skeletal Ewing sarcoma

To evaluate the diagnostic accuracy of (18)F-FDG PET/CT for detecting recurrence in patients with primary skeletal Ewing sarcoma. We retrospectively analysed data from 53 patients (age 20.1 ± 10.5 years, 39 male) who had undergone 71 (18)F-FDG PET/CT studies for suspected recurrence (52 studies) or for routine follow-up (19 studies) after primary therapy of skeletal Ewing sarcoma. (18)F-FDG PET/CT studies were evaluated qualitatively and quantitatively (maximum standardized uptake value, SUVmax) by two nuclear medicine physicians in consensus. Sensitivity, specificity, predictive values and accuracy were calculated on per study basis. Clinical/imaging follow-up (minimum 6 months) and/or histopathology (when available) were taken as the reference standard. Of the total of 71 (18)F-FDG PET/CT studies, 42 (59.1%) were positive for recurrence and 29 (40.9%) were negative for recurrence. Local recurrence was most common (38 studies) followed by bone metastasis (9 studies), and node and lung metastasis (2 studies each). Of the 71 studies, 38 were true-positive, 27 were true-negative, 4 were false-positive and 2 were false-negative. Overall per study based sensitivity was 95%, specificity was 87%, PPV was 90%, NPV was 93% and accuracy was 91.5%. No significant difference was found in the accuracy of PET/CT between the suspected recurrence group and the routine follow-up group (94% vs. 84%; P = 0.390). Overall mean lesion SUVmax was 7.8 ± 4.1 (range 1.9-17.2). No site-based difference was found in SUVmax. (18)F-FDG PET/CT demonstrates high diagnostic accuracy for detecting recurrence in patients with primary skeletal Ewing sarcoma, when it is suspected (clinically or on imaging) or during routine follow-up.

Virtual 18F-FDG PET/CT bronchoscopy for lymph node staging in non-small-cell lung cancer patients: present and future applications

Virtual 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) bronchoscopies provide virtually realistic, 3D endoscopic views of the airways combining anatomical and functional data at a high resolution. Today, even very small airways can be imaged by virtual bronchoscopy. 18F-FDG PET/CT bronchoscopy images are generated from standard whole-body 18F-FDG PET/CT scan source data without any additional radiation exposure. The purpose of this review was to give an overview over the studies that are currently available, to provide the technical background of 18F-FDG PET/CT bronchoscopy and to explain the diagnostic accuracy of 18F-FDG PET/CT bronchoscopy. Moreover, this manuscript highlights potential future applications of this promising new imaging technique.

Does hyperglycemia affect the diagnostic value of 18F-FDG PET/CT?

BackgroundNet cellular uptake of 18F-FDG is adversely affected by elevated plasma glucose levels. The purpose of our study was to investigate the influence of hyperglycemic state at the time of 18F-FDG injection on the diagnostic accuracy of 18F-FDG PET/CT. MethodPre-scan plasma glucose levels of all patients who were referred for PET/CT with an oncologic indication during the year 2005 were reviewed. All seventy-six patients (50 men, 26 women, mean age±SD: 65.5±9.7 years) with pre-scan glucose level higher than 140mg/dL (mean plasma glucose level±SD: 168.7±30.8, ranging from 140 to 260mg/dL) were enrolled into our study. The accuracy of PET/CT scans was assessed using concurrent or follow-up CT, MRI and histologic evidences as well as clinical follow-up as the reference standard. ResultsPET/CT was true positive in 37 patients, true-negative in 30 patients, false negative in 6 patients and false positive in 3 patients. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 18F-FDG PET/CT on a patient basis were 86%, 90.9%, 92.5%, 83.3% and 88.1%, respectively. Diabetes mellitus was recorded in 50 patients. No significant diagnostic accuracy difference between diabetics and non-diabetics was noticed. ConclusionOur study suggests that 18F-FDG accumulation of malignant lesions remains sufficiently high for reliable qualitative clinical diagnosis in chronic and acute hyperglycemic states. However, regarding the discordant and inconclusive results of the available reports and the remarkable concerns with reference to the adverse effects of elevated plasma glucose levels on the diagnostic accuracy of 18F-FDG PET/CT scans, further direct clues seems to be required and should be provided by future studies.

Does hyperglycemia affect the diagnostic value of 18F-FDG PET/CT?

BackgroundNet cellular uptake of 18F-FDG is adversely affected by elevated plasma glucose levels. The purpose of our study was to investigate the influence of hyperglycemic state at the time of 18F-FDG injection on the diagnostic accuracy of 18F-FDG PET/CT. MethodPre-scan plasma glucose levels of all patients who were referred for PET/CT with an oncologic indication during the year 2005 were reviewed. All seventy-six patients (50 men, 26 women, mean age±SD: 65.5±9.7 years) with pre-scan glucose level higher than 140mg/dL (mean plasma glucose level±SD: 168.7±30.8, ranging from 140 to 260mg/dL) were enrolled into our study. The accuracy of PET/CT scans was assessed using concurrent or follow-up CT, MRI and histologic evidences as well as clinical follow-up as the reference standard. ResultsPET/CT was true positive in 37 patients, true-negative in 30 patients, false negative in 6 patients and false positive in 3 patients. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 18F-FDG PET/CT on a patient basis were 86%, 90.9%, 92.5%, 83.3% and 88.1%, respectively. Diabetes mellitus was recorded in 50 patients. No significant diagnostic accuracy difference between diabetics and non-diabetics was noticed. ConclusionOur study suggests that 18F-FDG accumulation of malignant lesions remains sufficiently high for reliable qualitative clinical diagnosis in chronic and acute hyperglycemic states. However, regarding the discordant and inconclusive results of the available reports and the remarkable concerns with reference to the adverse effects of elevated plasma glucose levels on the diagnostic accuracy of 18F-FDG PET/CT scans, further direct clues seems to be required and should be provided by future studies.

Diagnostic accuracy of 18F-FDG and 11C-PIB-PET for prediction of short-term conversion to Alzheimer’s disease in subjects with mild cognitive impairment

In recent years, the role of PET imaging in the prediction of mild cognitive impairment (MCI) to Alzheimer's disease (AD) conversion has been the subject of many longitudinal studies. The purpose of this study was to perform a meta-analysis to estimate the diagnostic accuracy of (18) F-fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) and (11) C-Pittsburgh Compound B-positron emission tomography (PIB-PET) for prediction of short-term conversion to AD in patients with MCI. The MEDLINE and EMBASE databases were systematically searched for relevant studies. Methodological quality of the included studies was assessed. Sensitivities and specificities of PET in individual studies were calculated and meta-analysis was undertaken with a random-effects model. A summary receiver operating characteristic (SROC) curve was constructed with the Moses-Shapiro-Littenberg method. Heterogeneity was tested, and the presence of publication bias was assessed. Potential sources for heterogeneity were explored by assessing whether or not certain covariates significantly influenced the relative diagnostic odds ratio (DOR). Pooled estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), DOR and the SROC curve of each PET imaging were determined. A total of 13 research studies (seven FDG-PET and six PIB-PET) met inclusion criteria and had sufficient data for statistical analysis. FDG-PET pooled estimates had 78.7% sensitivity (95% CI, 68.7-86.6%),74.0% specificity (95% CI, 67.0-80.3%), 18.1 LR+(95% CI, 7.3-45.0) and 0.32 LR-(95% CI, 0.16-0.61); and PIB-PET pooled estimates had 93.5% sensitivity (95%CI, 71.3-99.9%), 56.2% specificity (95% CI, 47.2-64.8%), 2.01 LR+ (95% CI, 1.57-2.58) and 0.17 LR-(95% CI, 0.08-0.36). Overall DOR was 17.3 (95% CI, 5.08-59.2) for FDG-PET and 12.8 (95% CI, 5.35-30.54) for PIB-PET. Area under the SROC curve was 0.88 ± 0.05 for FDG-PET and 0.85 ± 0.04 for PIB-PET. The data from FDG-PET research studies had high heterogeneity and funnel plot suggested a publication bias. The diagnostic accuracy determined for both FDG-PET and PIB-PET in this meta-analysis suggests that they are potentially valuable techniques for prediction of progression in patients with MCI. Both have their advantages and their combined use is a promising option for prediction purposes depending on availability and experience.

Correspondence: Diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions

Correspondence: Diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions

Diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions and staging ovarian cancer: Correlation with transvaginal ultrasonography, computed tomography, and histology

To (a) assess the accuracy of 18F-FDG PET/CT in distinguishing malignant from benign pelvic lesions, compared to transvaginal ultrasonography (TVUS) and (b) to establish the role of whole-body 18F-FDG PET/CT, compared to contrast enhanced computed tomography (CT), in staging patients with ovarian cancer. Fifty consecutive patients with a pelvic lesion, already scheduled for surgery on the basis of physical examination, TVUS, and serum Ca125 levels, were enrolled in the study. Patients' age ranged between 23 and 89 years (mean 64). All patients underwent TVUS including a colour Doppler study followed by a thorax and abdominal CT scan, and whole-body 18F-FDG PET/CT within 2 weeks prior to surgery. Histological findings obtained at surgery were taken as the 'gold standard' to compare 18F-FDG PET/CT and TVUS, and 18F-FDG PET/CT vs. CT. When tissue analysis showed ovarian cancer, the accuracy of 18F-FDG PET/CT and CT were compared for the purpose of obtaining a precise staging. At surgery, the ovarian lesions were malignant in 32/50 patients (64%) and benign in the remaining 18/50 patients (36%). The sensitivity, specificity, NPV, PPV and accuracy of 18F-FDG PET/CT were 87%, 100%, 81%, 100% and 92%, respectively, compared with 90%, 61%, 78%, 80% and 80%, respectively, for TVUS. In staging ovarian cancer, 18F-FDG PET/CT results were concordant with final pathological staging in 22/32 (69%) patients while CT results were concordant in 17/32 (53%) patients. CT incorrectly down-staged four out of six stage IV patients by missing distant metastasis in the liver, pleura, mediastinum, and in left supraclavicular lymph nodes, which were correctly detected by 18F-FDG PET/CT. PET/CT with 18F-FDG provides additional value to TVUS for the differential diagnosis of benign from malignant pelvic lesions, and to CT for the staging of ovarian cancer patients.