Real-Life Use of [68Ga]Ga-DOTANOC PET/CT in Confirmed and Suspected NETs from a Prospective 5-Year Electronic Archive at an ENETS Center of Excellence: More Than 2000 Scans in More Than 1500 Patients.

The recent introduction of novel treatments for advanced neuroendocrine tumors (NETs) and the well-established impact of clinical case discussion within dedicated multidisciplinary teams indicates the need to promote the centralization of rare diseases, such as NENs (neuroendocrine neoplasms). Data on the real-life use of and indications for [68Ga]Ga-DOTANOC PET/CT were collected from a prospective monocentric 5-year electronic archive including consecutive patients with confirmed and suspected NETs (September 2017 to May 2022). Overall, 2082 [68Ga]Ga-DOTANOC PET/CT scans (1685 confirmed NETs, 397 suspected NETs) were performed in 1537 patients. A high positivity rate was observed across different clinical settings (approximately 70%). Approximately 910/2082 scans were requested by the local oncology ward (851 confirmed NETs, 59 suspected NETs). The following observations were found: (i) the detection rate across all indications was 73.2% (higher for staging, peptide receptor radioligand therapy (PRRT) selection, and treatment response assessment); (ii) in suspected NETs, PET was more often positive when based on radiological findings. This systematic data collection in a high-volume diagnostic center represents a reliable cohort reflecting the global trends in the use of [68Ga]Ga-DOTANOC PET/CT for different clinical indications and primary tumor sites, but prompts the need for further multicenter data sharing in such a rare and slowly progressive disease setting.

Association of CSF and PET markers of neurodegeneration with electroclinical progression in Lafora disease.

Purpose: To evaluate the electro-clinical features in association with laboratory and instrumental correlates of neurodegeneration to detect the progression of Lafora disease (LD). Methods: We investigated the electro-clinical longitudinal data and CSF Aß42, p-tau181 and t-tauAg, amyloid, and 18F-FDG PET of five unrelated LD families. Results: Three progressive electro-clinical stages were identified. The early phase was characterized by rare, generalized tonic-clonic and focal visual seizures, followed by the occurrence of myoclonus after a period ranging from 2 to 12 months. The intermediate stage, usually occurring 2 years after the onset of epilepsy, is characterized by a worsening of epilepsy and myoclonus associated with progressive dementia and cerebellar signs. Finally, the late stage, evolving after a mean period of 7 ± 1.41 years from the onset of the disease, was characterized by gait ataxia resulting in bedriddenness, severe dementia, daily/pluri-daily myoclonus, drug-resistant epilepsy, clusters of seizures or status epilepticus, and medical complications. Amyloid (CSF Aß42, amyloid PET) and neurodegenerative (CSF p-tau181 and t-tauAg, FDG-PET) biomarkers indicate a pattern of cognitive impairment of the non-Alzheimer's disease type. A total of 80% of the LD patients showed more severe hypometabolism in the second FDG-PET scan compared to the first scan performed in a lower phase; the lateral temporal lobe and the thalamus hypometabolism were associated with the presence of intermediate or late phase. Conclusions: Three electroclinical and 18F-FDG PET evolutive stages are useful biomarkers for the progression of LD and could help to evaluate the efficacy of new disease-modifying treatments. The combination of traditional CSF biomarkers improves the diagnostic accuracy of cognitive decline in LD patients, indicating a cognitive impairment of the non-Alzheimer's disease type.

A Peculiar 18 F-FDG Spinal Uptake Helps Diagnosis and Effective Treatment of Polymyalgia Rheumatica : "The Corset Sign".

ABSTRACT: Polymyalgia rheumatica is the most common inflammatory rheumatic disease in elderly people, usually develops in patients older than 50 years, more frequently in females. An emerging imaging tool in the diagnostic workup of this condition is whole-body PET/CT, which allows an overall assessment of the articular and extra-articular structures involved.

Two birds with one stone: can [68Ga]Ga-DOTANOC PET/CT image quality be improved through BMI-adjusted injected activity without increasing acquisition times?

OBJECTIVES: To assess how patients' dependent parameters may affect [68Ga]Ga-DOTANOC image quality and to propose a theoretical body mass index (BMI)-adjusted injected activity (IA) scheme, to improve imaging of high weight patients. METHODS: Among patients prospectively enrolled (June-2019 and May-2020) in an Institutional Ethical Committee-approved electronic archive, we included those affected by primary gastro-entero-pancreatic (GEP) or lung neuroendocrine tumour and referred by our Institutional clinicians (excluding even minimal radiopharmaceutical extravasation, movement artefacts, renal insufficiency). All PET/CT images were acquired following EANM guidelines and rated for visual quality (1 = non-diagnostic, 2 = poor, 3 = moderate, 4 = good). Collected data included patient's body mass, height, BMI, age, IA (injected activity), IA/Kg (IAkg), IA/BMI (IABMI), liver SUVmean, liver SUVmax standard deviation, liver-signal-to-noise (LSNR), normalised_LSNR (LSNR_norm) and contrast-to-noise ratio (CNR) for positive scans and were compared to image rating (poor vs moderate/good). RESULTS: Overall, 77 patients were included. Rating concordance was high (agreement = 81.8%, Fleiss k score = 0.806). All patients' dependent parameters resulted significantly different between poor-rated and moderate/good-rated scans (IA: p = 0.006, IAkg: p =< 0.001, body weight: p =< 0.001, BMI: p =< 0.001, IABMI: p =< 0.001). Factors significantly associated with moderate/good rating were BMI (p =< 0.001), body weight (p =< 0.001), IABMI (p =< 0.001), IAkg (p = 0.001), IA (p = 0.003), LSNR_norm (p = 0.01). The BMI-based model presented the best predictive efficiency (81.82%). IABMI performance to differentiate moderate/good from poor rating resulted statistically significant (IA-AUC = 0.78; 95% CI: 0.68-0.89; cut-off value of 4.17 MBq*m2/kg, sensitivity = 81.1%, specificity = 66.7%). If BMI-adjusted IA (=4.17*BMI) would have been applied in this population, the median IA would have slightly inferior (-4.8%), despite a different IA in each patient. ADVANCES IN KNOWLEDGE: BMI resulted the best predictor of image quality. The proposed theoretical BMI-adjusted IA scheme (4.17*BMI) should yield images of better quality (especially in high-BMI patients) maintaining practical scanning times (3 min/bed).

Can Q.Clear reconstruction be used to improve [68 Ga]Ga-DOTANOC PET/CT image quality in overweight NEN patients?

AIM/INTRODUCTION: Digital PET/CT allows Q.Clear image reconstruction with different Beta (ß) levels. However, no definitive standard ß level for [68 Ga]Ga-DOTANOC PET/CT has been established yet. As patient's body mass index (BMI) can affect image quality, the aim of the study was to visually and semi-quantitatively assess different ß levels compared to standard OSEM in overweight patients. MATERIALS AND METHODS: Inclusion criteria: (1) patients with NEN included in a prospective CE-approved electronic archive; (2) [68 Ga]Ga-DOTANOC PET/CT performed on a digital tomograph between September2019/March2021; (3) BMI ≥ 25. Images were acquired following EANM guidelines and reconstructed with OSEM and Q.Clear with three ß levels (800, 1000, 1600). Scans were independently reviewed by three expert readers, unaware of clinical data, who independently chose the preferred ß level reconstruction for visual overall image quality. Semi-quantitative analysis was performed on each scan: SUVmax of the highest uptake lesion (SUVmax-T), liver background SUVmean (SUVmean-L), SUVmax-T/SUVmean-L, Signal-to-noise ratio for both liver (LSNR) and the highest uptake lesion (SNR-T), Contrast-to-noise ratio (CNR). RESULTS: Overall, 75 patients (median age: 63 years old [23-87]) were included: pre-obesity sub-group (25 ≤ BMI < 30, n = 50) and obesity sub-group (BMI ≥ 30, n = 25). PET/CT was positive for disease in 45/75 (60.0%) cases (14 obese and 31 pre-obese patients). Agreement among readers' visual rating was high (Fleiss κ = 0.88) and the ß1600 was preferred in most cases (in 96% of obese patients and in 53.3% of pre-obese cases). OSEM was considered visually equal to ß1600 in 44.7% of pre-obese cases and in 4% of obese patients. In a minority of pre-obese cases, OSEM was preferred (2%). In the whole population, CNR, SNR-T and LSNR were significantly different (p < 0.001) between OSEM and ß1600, conversely to SUVmean-L (not significant). These results were also confirmed when calculated separately for the pre-obesity and obesity sub-groups ß800 and ß1000 were always rated inferior. CONCLUSIONS: Q.Clear is a new technology for PET/CT image reconstruction that can be used to increase CNR and SNR-T, to subsequently optimise overall image quality as compared to standard OSEM. Our preliminary data on [68 Ga]Ga-DOTANOC PET/CT demonstrate that in overweight NEN patients, ß1600 is preferable over ß800 and ß1000. Further studies are warranted to validate these results in lesions of different anatomical region and size; moreover, currently employed interpretative PET positivity criteria should be adjusted to the new reconstruction method.

"2-step MCI-AD": a simple scoring system to predict rapid conversion from mild cognitive impairment to Alzheimer dementia.

BACKGROUND: Several techniques are available to identify, among patients with mild cognitive impairment (MCI), those at risk of conversion to Alzheimer dementia (CAD). However, simple cost-effective methods to assess the risk are not available yet. METHODS: This retrospective study included 143 MCI outpatients (76.6±5.2 years, 46.8% women). Baseline variables were common neuropsychological tests (including Mini Mental State Examination-MMSE and Montreal Cognitive Assessment-MoCA), brain CT and 18F-fluorodeoxyglucose (FDG)-PET. Outcome variable was CAD after 1 year. RESULTS: At follow-up, 31 (21.7%) patients had CAD. In multivariable analysis (OR, 95% CI), female sex (4.7, 1.6-14.0), MoCA-executive component <3 (6.3, 2.1-19.2), left medial temporal atrophy (MTA) ≥3 (5.4, 1.9-15.7) and FDG-PET suggesting CAD (5.4, 1.9-15.7) were associated with CAD (area under ROC curve 0.873). Without FDG-PET, MMSE score <28 remained associated with CAD (6.0, 2.2-16.9). As first step (before FDG-PET execution), we counted 1 point for MMSE <28, executive MoCA <3 and left MTA ≥3. With 2-3 points CAD probability was high (75%) and with 0 points it was low (6.5%). Thus, FDG-PET (second step) might be performed only in patients with 1 point (probability 19.7%, 42.7% of patients). Among them, 35% had a positive FDG-PET, suggesting high risk. Overall, 28.0% of patients were considered at high risk (specificity 83.9%, sensitivity 71.0%, accuracy 81.1%). CONCLUSION: With a 2-step procedure, less than half of MCI patients might undergo FDG-PET and nearly a quarter of our patients was found to be at high CAD risk, including almost three quarters of future CADs.

Prognostic Value of 68Ga-DOTANOC PET/CT SUVmax in Patients with Neuroendocrine Tumors of the Pancreas.

UNLABELLED: This study was performed to investigate the role of (68)Ga-DOTANOC SUVmax as a potential prognostic factor in patients with pancreatic neuroendocrine tumor (pNET). METHODS: Among the patients who underwent (68)Ga-DOTANOC PET/CT, we retrospectively collected the data of those who had G1 or G2 pNET (2010 World Health Organization classification), presented with disease on PET/CT and CT, and had at least 6 mo of follow-up. Patients with multiple endocrine neoplasia were excluded. RESULTS: Overall, 43 patients were included. No significant differences in SUVmax were observed with respect to sex, tumor syndrome, stage, World Health Organization classification, or Ki-67. During follow-up (median, 20 mo), 11 patients (35.6%; median, 33 mo; interquartile range, 20-48 mo) had stable disease and 32 (74.4%; median, 19 mo; interquartile range, 14-26 mo) had progressive disease. SUVmax at 24 mo of follow-up was significantly higher (P = 0.022) in patients with stable disease than in patients with progressive disease. The best SUVmax cutoff ranged from 37.8 to 38.0. The major risk factors for progression included an SUVmax of no more than 37.8 (hazard ratio, 3.09; P = 0.003), a Ki-67 of more than 5% (hazard ratio, 2.89; P = 0.009), and medical therapy alone (hazard ratio, 2.36; P = 0.018). Advanced stage (IV) (P = 0.026), an SUVmax of less than 37.8 (P = 0.043), and medical therapy alone (P = 0.015) were also confirmed at multivariate analysis. Median progression-free survival was 23 mo. Significant differences in progression-free survival were observed in relationship to Ki-67 (median, 45 mo for Ki-67 ≤ 5% and 20 mo for Ki-67 > 5%; P = 0.005), SUVmax (<37.8 vs. >38.0: 16.0 vs. 27.0 mo; P = 0.002), and type of therapy (medical vs. peptide receptor radionuclide therapy: 16.0 vs. 26.0 mo; P = 0.014). CONCLUSION: (68)Ga-DOTANOC SUVmax is a relevant prognostic factor in patients with G1 and G2 pNET, and its routine use will improve disease characterization and management in these patients, who may present with atypical cases showing heterogeneous clinical behavior.

Pretherapeutic dosimetry in patients affected by metastatic thyroid cancer using 124I PET/CT sequential scans for 131I treatment planning.

PURPOSE: This study evaluates the use of sequential I PET/CT for predicting absorbed doses to metastatic lesions in patients with differentiated thyroid cancer undergoing I therapy. METHODS: From July 2011 until July 2013, 30 patients with metastatic differentiated thyroid cancer were enrolled. Each participant underwent PET/CT at 4, 24, 48, and 72 hours with 74 MBq of I. Blood samples and whole-body exposure measurements were obtained to calculate blood and red marrow doses. Activity concentrations and lesion volumes obtained from PET/CT were used to evaluate tumor doses with medical internal radiation dose formalism and spheres modeling. Mean administered I therapeutic dose was 5994 MBq (range, 1953-11,455 MBq). RESULTS: I PET/CT demonstrated all lesions detected by posttherapy I whole-body scans. Mean dose rates for blood, red marrow, and lesions were as follows: 0.07 ± 0.02 mGy/MBq, 0.05 ± 0.02 mGy/MBq, and 46.5 ± 117 mGy/MBq, respectively. Despite the high level of thyroid-stimulating hormone and CT detectable lesions, 15 of 30 patients did not show any abnormal I uptake. CONCLUSIONS: The quantitative value of I PET/CT allows simple and accurate evaluation of lesion dosimetry following medical internal radiation dose formalism. Negative I PET/CT predicts absence of iodine avidity, potentially allowing avoidance of therapeutically ineffective I administration.

Incidentally detected increased FDG uptake in bowel and its correlation with hystopathological data: our experience in a case series study.

When an intense intestinal FDG accumulation occurs, especially if focal, it can be referred to either physiological intestinal activity or bowel disease, thus leading to a radical change in patient's prognosis. Within a year, we recommended a colonoscopy to 103 of 7365 patients who were subjected to a total body FDG PET/CT. In a case-series study, we re-evaluated the patients and their lesions if already investigated with colonoscopy and biopsy. Only 18 patients were included in our study, but in none of them biopsy was negative and 3 adenocarcinomas, 8 adenomas, 5 inflammatory patterns, 1 hyperplastic polyp and 1 eosinophilic infiltrate were diagnosed. In 16 patients, no suspicion was present and diagnosis was absolutely incidental. Besides, among the three major groups (adenocarcinomas, adenomas and phlogosis), SUVmax values were significantly different. Adenocarcinomas are linked with high SUVmax values (ranging from 8.3 to 20.2) and large size (ranging from 26 to 43 mm). PET/CT sensitivity is low in detecting adenomas, being 71.4% if they are larger than 6 mm and 50% if SUVmax is lower than 4.9. SUVmax values in inflammatory lesions can range from 5.7 to 12. Colorectal cancer is still the second leading cause of cancer death, for this reason in many countries screening programs have been approved and colonoscopy is considered the golden standard. PET/CT cannot be considered as a screening test, but if it incidentally reveals intestinal abnormalities, this data cannot be underestimated and colonoscopy is highly recommended.

18F-FDG PET/CT impact on testicular tumours clinical management.

PURPOSE: Testicular tumour is the most common malignancy in young men. The diagnostic work-up is mainly based on morphological imaging. The aim of our study was to evaluate the clinical impact of (18)F-FDG PET/CT in patients with testicular tumour. METHODS: We retrospectively evaluated all patients studied by (18)F-FDG PET/CT at our centre. Inclusion criteria were: pathological confirmation of testicular tumour, contrast-enhanced CT scan performed within a month of the PET/CT scan, and clinical/imaging follow-up performed at the Oncology Unit of our hospital. Overall, 56 patients were enrolled and 121 PET/CT scans were evaluated. (18)F-FDG PET/CT was performed following standard procedures and the results were compared with clinical, imaging and follow-up data. Clinicians were contacted to inquire whether the PET/CT scan influenced the patient's management. Answers were scored as follows: start/continue chemotherapy or radiotherapy, indication for surgery of secondary lesions, and clinical surveillance. RESULTS: On a scan basis, 51 seminoma and 70 nonseminoma (NS) cases were reviewed. Of the 121 cases. 32 were found to be true-positive, 74 true-negative, 8 false-positive and 6 false-negative by PET/CT. PET/CT showed good sensitivity and specificity for seminoma lesion detection (92% and 84%, respectively), but its sensitivity was lower for NS forms (sensitivity and specificity 77% and 95%, respectively). The PET/CT scan influenced the clinical management of 47 of 51 seminomas (in 6 chemotherapy was started/continued, in 3 radiotherapy was started/continued, in 2 surgery of secondary lesions was performed, and in 36 clinical surveillance was considered appropriate), and 59 of 70 NS (in 18 therapy/surgery was started/continued, and in 41 clinical surveillance was considered appropriate). CONCLUSION: Our preliminary data demonstrate the potential usefulness of PET/CT for the assessment of patients with testicular tumour. It provides valuable information for the clinical management, particularly for clinical surveillance, post-therapy assessment and when relapse is suspected.

The clinical use of PET with (11)C-acetate.

The aim of this review is to evaluate clinical applications of (11)C-acetate positron emission tomography (PET). Acetate is quickly metabolized into acetyl-CoA in human cells. In this form it can either enter into the tricarboxylic acid cycle, thus producing energy, as happens in the myocardium, or participate in cell membrane lipid synthesis, as happens in tumor cells. (11)C-acetate PET was originally employed in cardiology, to study myocardial oxygen metabolism. More recently it has also been used to evaluate myocardial perfusion, as well as in oncology. The first studies of (11)C-acetate focused on its use in prostate cancer. Subsequently, (11)C-acetate was studied in other urological malignancies, as well as renal cell carcinoma and bladder cancer. Well differentiated hepatocellular carcinoma represents an (18)F-fluoro-deoxyglucose ((18)F-FDG) PET pitfall, so many authors have proposed to use (11)C-acetate in addition to (18)F-FDG in studying this tumor. (11)C-acetate PET has also been used in other malignancies, such as brain tumors and lung carcinoma. Some authors reported a few cases in which (11)C-acetate PET incidentally found multiple myeloma or rare tumors, such as thymoma, multicentric angiomyolipoma of the kidney and cerebellopontine angle schwannoma. Lastly, (11)C-acetate PET was also employed in a differential diagnosis case between glioma and encephalitis. The numerous studies on (11)C-acetate have demonstrated that it can be used in cardiology and oncology with no contraindications apart from pregnancy and the necessity of a rapid scan. Despite its limited availability, this tracer can surely be considered to be a promising one, because of its versatility and capacity to even detect non (18)F-FDG-avid neoplasm, such as differentiated lung cancer or hepatocellular carcinoma.

F-18 FDG PET/CT detects muscle involvement in Erdheim-Chester disease.

A case of Erdheim-Chester disorder, a rare non-Langerhans' cell histiocytosis, was referred for restaging by F-18 FDG PET/CT more than 10 years after initial diagnosis. The patient presented diabetes insipidus, hypergondotropic hypogonadism, and osteosclerotic lesions. Previous bone scintigraphy documented pathognomonic long bones' involvement. Chronic steroid and hormone replacement therapy was administered, and the patient was asymptomatic. F-18 FDG PET/CT was useful for disease restaging at cardiac and soft tissues level.

Value of FDG PET/CT in patients with treated ovarian cancer and raised CA125 serum levels.

PURPOSE: Patients treated for ovarian cancer are usually referred for 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) in case of increased Carcinoma Antigen 125 (CA125) but negative conventional imaging. However, there is not enough in the literature to support the value of FDG PET/CT in this context. This study aimed to assess role of FDG PET/CT in a cohort of patients with treated ovarian cancer and correlate the results with serum levels of CA125. PROCEDURES: We retrospectively studied 175 patients, mean age 65.2 years (range 24-88 years) who had radical treatment for ovarian cancer (chemotherapy, surgery or combination). The patients had a standard FDG PET/CT and measurement of serum CA125 within a month of the scan. PET/CT was considered positive if demonstrated areas of abnormally increased metabolic activity unrelated to physiological distribution, on the basis of a visual analysis. The results of PET/CT imaging were compared to the level of CA125, and receiver operating characteristic (ROC) curves were plotted and area-under-the curve (AUC) statistics were computed. Cytologic or histologic data or clinical and imaging follow-up were taken as gold standard. RESULTS: Patients were divided into five groups based on CA125 values. The average level of CA125 was 107.7 (range 3-867, SD 166.1). PET/CT was positive in 125/175 cases (71.4%), mean value of CA125 132.2 (SD 182.9) and negative in 50/175 (28.6%), mean value of CA125 46.4 (SD 89.3). In descriptive ROC analyses, the discriminatory power of this marker was relatively high (AUC statistics 0.77, range = 0.703-0.8). The optimal cut-off point of CA125 after treatment to reflect active disease on PET/CT was 18 U/mL achieving a detection rate of 85.6%. There was no relation between PET/CT negativity and the histological type of the tumor. CONCLUSION: PET/CT was able to detect active disease at relatively low levels of CA125, thereby facilitating the early diagnosis of recurrence or residual disease. Also in patients with low CA125 levels (<30), PET/CT had a relatively high detection rate (53%). According to our preliminary results, the use of FDG PET/CT in this setting is justified even with low serum CA125 levels.

I-123 MIBG scintigraphy and 68Ga-DOTANOC PET/CT negative but F-18 DOPA PET/CT positive pheochromocytoma: a case report.

We observed a 34-year-old man who was incidentally found to have an adrenal mass during surgical follow-up for perforated ulcer. The patient was subjected to I-123 MIBG scintigraphy, 68Ga-DOTANOC PET/CT, and F-18 DOPA PET/CT. Only F-18 DOPA PET/CT showed evidence of an avid adrenal mass. A CT-guided biopsy was performed and it was suggestive for pheochromocytoma. He underwent surgery and a pheochromocytoma, about 40 mm in diameter, was detected. Traditionally, I-123 MIBG scintigraphy has been used in detecting chromaffin cell tumors, but more recently it had been demonstrated that a certain part of pheochromocytoma could be false-negative on scintigraphy.

FDG-PET/CT in advanced ovarian cancer staging: value and pitfalls in detecting lesions in different abdominal and pelvic quadrants compared with laparoscopy.

INTRODUCTION AND AIM: Ovarian carcinoma (OC) is a common cancer in the Western Countries, and an important cause of death in patients suffering with gynaecologic malignancies. The majority of patients present with advanced disease at the time of diagnosis. Treatment with debulking surgery followed by chemotherapy is the standard approach while chemotherapy is contemplated when surgery is not possible. A correct pre-operative staging is important to ensure a most appropriate management. Laparoscopy (LPS) is the standard diagnostic tool for the assessment of intraperitoneal infiltration but is invasive and requires general anaesthesia. FDG-PET/CT is increasingly used for staging different types of cancer, and the aim of this study is to assess the value of FDG-PET/CT in staging advanced OC and its sensitivity to detect lesions in different quadrants of the abdominal-pelvic area compared to laparoscopy. MATERIALS AND METHODS: From September 2004 till April 2008, 40 patients with high suspicion of OC were referred to our hospital for diagnostic LPS to explore the possibility of optimal debulking surgery. Those who were not suitable for surgery were referred for chemotherapy. Before chemotherapy, the patients underwent an FDG-PET/CT scan. The findings in 9 quadrants of abdominal-pelvic area (total 360 quadrants) for PET/CT and LPS were recorded and compared. RESULTS: In 14/360 areas (3.8%), surgical evaluation was not possible because of presence of adhesions, thus the number of areas explored by laparoscopy was 346. Tumour was found in 308 quadrants (38 quadrants free of disease). PET/CT was positive in all 40 patients with true negative results in 26/346 quadrants (7.5%), and true positives results in 243/346 quadrants (70.2%). False positive and negative PET/CT results were found in 12/346 and 65/346 quadrants, respectively. False positive PET/CT findings were evenly present in all quadrants. False negative PET/CT findings were present in 31/109 (28.4%) upper abdominal quadrants (epigastrium and diaphragmatic areas). Final analysis showed a sensitivity and specificity for PET/TC of 78.9 and 68.4% respectively with a positive predictive value of 95.3%. A significant difference was noted between mean SUVmax associated with lesions smaller or larger than 0.5 cm (p=0.006). CONCLUSION: Our results suggest that PET/CT may prove a useful tool for pre-surgical staging of ovarian cancer with a sensitivity and specificity of 78 and 68%, respectively. However, it may be used in combination with laparoscopy for better results. PET/CT showed an adequate correlation between SUVmax values and laparoscopy findings of lesions>5mm, but a high rate of false negative results in lesions<5mm such as in carcinomatosis. PET/CT should be used carefully in early stage disease, with low risk of peritoneal infiltration, because of high rate of false positive results, to avoid unnecessary therapy procedures.