Evaluation of quantitative criteria for glioma grading with static and dynamic 18F-FDopa PET/CT.

PURPOSE: The aim of this study was to compare various acquisition and processing protocols for noninvasive glioma grading using either static or dynamic (18)F-FDopa PET. METHODS: Dynamic studies were performed in 33 patients. Based on histopathological analysis, 18 patients had a high-grade (HG) tumor and 15 patients had a low-grade (LG) tumor. For static imaging, SUV(mean) and SUV(max) were calculated for different acquisition time ranges after injection. For dynamic imaging, the transport rate constant k1 was calculated according to a compartmental kinetic analysis using an image-derived input function. RESULTS: With the use of a 5-minute static imaging protocol starting at 38 minutes after injection, newly diagnosed HG tumors could be distinguished from LG tumors with a sensitivity of 70% and a specificity of 90% with a threshold of SUV(mean) of 2.5. In recurrent tumors, a sensitivity of 100% and a specificity of 80% for identifying HG tumors were obtained with a threshold set to 1.8. Dynamic imaging only slightly, but nonsignificantly, improved differential diagnosis. CONCLUSIONS: Static and dynamic imaging without blood sampling can discriminate between LG and HG for both newly diagnosed and recurrent gliomas. In dynamic imaging, excellent discrimination was obtained by considering the transport rate constant k1 of tumors. In static imaging, the best discrimination based on SUV was obtained for SUV(mean) calculated from a 5-minute acquisition started at 38 minutes after injection.

18F-FDG PET/CT imaging of Sister Mary Joseph's nodule.

An 82-year-old woman was followed up for an uterine cervical adenocarcinoma treated by surgery. A whole-body fluorodeoxyglucose positron emission tomography study revealed a pathologic fluorodeoxyglucose uptake located in the umbilicus associated to peritoneal carcinomatosis. Biopsy of the umbilical nodule demonstrated an umbilical metastasis from the uterine adenocarcinoma, the so-called "Sister Mary Joseph's nodule."

18F-Fluorodeoxyglucose positron emission tomography for the diagnosis of adrenocortical tumors: a prospective study in 77 operated patients.

CONTEXT: Most adrenal incidentalomas are nonfunctioning adrenocortical adenomas (ACAs). Adrenocortical carcinomas (ACCs) are rare but should be recognized at an early stage. OBJECTIVE: The objective of the study was to evaluate the usefulness of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) to predict malignancy in patients without a previous history of cancer. DESIGN: This was a prospective, multicenter study from 2001 to 2006. SETTING: The study was conducted at a network of seven university hospitals in Paris. PATIENTS: Seventy-seven patients were included. All underwent surgery because of hypersecretory and/or growing benign lesions (n = 18), obvious ACCs (n = 21), or radiologically indeterminate lesions (n = 38). MAIN OUTCOME MEASURE: The degree of (18)F-FDG PET uptake [maximum standardized uptake value (maxSUV)] was related to the pathological findings serving as a reference, and its diagnostic value was compared with that of computerized tomography (CT) scan. RESULTS: Pathology eventually diagnosed 43 ACAs, 22 ACCs, and 12 nonadrenocortical lesions. Using a cutoff value above 1.45 for adrenal to liver maxSUV ratio, the sensitivity and specificity to distinguish ACAs from ACCs were, respectively, 1.00 (95% confidence interval 0.85-1.00) and 0.88 (95% confidence interval 0.75-0.96). Among the 38 indeterminate lesions at CT scan, we could analyze a subgroup of 16 adrenocortical tumors with high unenhanced density (>10 HU) and an inappropriate washout: (18)F-FDG PET correctly predicted the benignity in 13 of 15 ACAs. CONCLUSIONS: In a multidisciplinary team approach, (18)F-FDG PET helps to manage suspicious CT scan lesions. An adrenal to liver maxSUV ratio less than 1.45 is highly predictive of a benign lesion.

High and typical 18F-FDG bowel uptake in patients treated with metformin.

PURPOSE: This prospective and bi-centric study was conducted in order to determine the impact of antidiabetic treatments (AD) on (18)F-FDG bowel uptake in type 2 diabetic patients. METHODS: Fifty-five patients with previously diagnosed and treated type 2 diabetes mellitus (group 1) were divided in two subgroups: AD treatment including metformin (n=32; group 1a) and AD treatment excluding metformin (n=23; group 1b). The 95 patients without diabetes mellitus made up controls (group 2). (18)F-FDG uptake in small intestine and colon was visually graded and semi-quantitatively measured using the maximum standardized uptake value. RESULTS: (18)F-FDG bowel uptake was significantly increased in AD patients (group 1) as compared to controls (group 2) (p<0.001). Bowel uptake was significantly higher in AD patients including metformin (group 1a) as compared to AD patients excluding metformin (group 1b) (p<0.01), whose bowel uptake was not significantly different from controls (group 2). A metformin treatment was predictive of an increased bowel uptake in the small intestine (odds ratio OR=16.9, p<0.0001) and in the colon (OR=95.3, p<0.0001), independently of the other factors considered in the multivariate analysis. Bowel uptake pattern in the patients treated with metformin was typically intense, diffuse and continuous along the bowel, strongly predominant in the colon, in both the digestive wall and lumen. CONCLUSION: This study emphasizes that metformin significantly increases (18)F-FDG uptake in colon and, to a lesser extent, in small intestine. It raises the question of stopping metformin treatment before an (18)F-FDG PET/CT scan is performed for intra-abdominal neoplasic lesion assessment.

[Positron emission tomography in internal medicine]. / Tomographie par émission de positons en médecine interne.

FDG-PET is now an established diagnostic tool in oncology. Fluorodeoxyglucose is not a specific tracer for malignant lesions but rather for elevated glucose metabolism, present not only in cancer but also in inflammatory and infectious lesions. FDG-PET has thus been suggested for diagnosis of fevers of unknown origin, deep bone or visceral infectious foci, inflammatory vasculitis or sarcoidosis and unknown primary tumors, all frequent situation in internal medicine. The main characteristics of FDG-PET are its ability to rule out focal inflammation or infection with a high degree of certainty when the examination is negative because of its good negative predictive value and its usefulness as an early marker of therapeutic response, compared with anatomy-based or conventional scintigraphic imaging. Large-scale prospective studies are necessary, however, before FDG-PET is integrated into routine clinical use. It should be compared with different techniques already validated (biology, radiology, conventional scintigraphic imaging) and its cost-effectiveness should be evaluated.

Pulmonary cement embolism after percutaneous vertebroplasty: a rare and nonthrombotic cause of pulmonary embolism.

Percutaneous vertebroplasty consists of injection of acrylic cement - polymethylmethacrylate - into a vertebral body to obtain pain relief and increase its mechanical stability. The procedure is indicated for painful hemangiomas and for painful vertebral compression fractures due to osteoporosis or malignancy. Although vertebroplasty is an efficient treatment, it is not free of complications. We present the case of a patient with pulmonary cement embolism after percutaneous vertebroplasty. Because such patients may be completely asymptomatic, but may also present with acute and severe, cardiovascular instability, clinicians and nuclear physicians should be aware that pulmonary embolism of polymethylmethacrylate may occur after percutaneous vertebroplasty.

[Understanding positon emission tomography (PET) with [18F]-FDG in clinical oncology. Informations dedicated to patients and relatives]. / Comprendre la tomographie par émission de positons au [ 18F]-FDG en cancérologie. Information à l'usage des personnes malades et de leurs proches.

In response to the evolution of the information-seeking behaviour of patients and concerns from health professionals regarding cancer patient information, the French National Federation of Comprehensive Cancer Centres (FNCLCC) introduced, in 1998, an information and education program dedicated to patients and relatives, the SOR SAVOIR PATIENT program (SSP). The methodology of this program adheres to established quality criteria regarding the elaboration of patient information. Cancer patient information, developed in this program, is based on clinical practice guidelines produced by the FNCLCC and the twenty French regional cancer centres, the National League against Cancer, the French Hospital Federation, the National Oncology Federation of Regional and University Hospitals, the French Oncology Federation of General Hospitals, many learned societies, as well as an active participation of patients, former patients and caregivers. The guidelines, "Standards, Options: Recommendations" (SOR) are used as primary information sources. The handbook SOR SAVOIR PATIENT Understanding positron emission tomography (PET) with [18F]-FDG in clinical oncology, integrally published in this issue of the Bulletin du Cancer, is an adapted version of the clinical practice guidelines (CPG) Standards, Options and Recommendations for positron emission tomography (PET) with [18F]-FDG in clinical oncology. The main objectives of this article are to allow persons affected by cancer and their close relatives to better understand this medical imaging technique and its implementation. This document also offers health professionals a synthetic evidence-based patient information source that should help them communicate that information during the physician-patient encounter. Positron emission tomography (PET) is a scintigraphy technique using a radiotracer, [18F]-fluorodeoxyglucose (abbreviated [18F]-FDG), administered intravenously into the patient's arm. This tracer, similar to glucose (sugar), binds to cancer cells and temporarily emits radiations that can be recorded by a special camera in the PET scanner. PET scanning can be used to obtain complementary information at different stages of the disease, whether for assessing diagnosis, treatment evolution or follow-up. By 2007, in the framework of the government plan against cancer, about seventy-five PET scanners are expected to be installed in France. Twenty-four are currently in use; a similar number is under installation. At the end of this process, all French regions should have at least one PET imaging equipment. The SOR SAVOIR PATIENT guide: Understanding positron emission tomography (PET) with [18F]-FDG in clinical oncology and the integral report of CPG SOR 2003: Standards, Options and Recommendations for positron emission tomography (PET) with [18F]-FDG in clinical oncology can be downloaded from the FNCLCC website: http:\\www.fnclcc.fr.

FDG-PET scan in local follow-up of irradiated head and neck squamous cell carcinomas.

We performed a prospective study to assess the value of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in the prediction of local control in irradiated head and neck squamous cell carcinomas (HNSCCs). Forty-two patients with irradiated HNSCCs underwent 49 FDG-PET scans between 3 and 6 months after the end of radiotherapy. The mean follow-up time after the first FDG-PET scan was 17 months. The result of the FDG-PET scan was true-positive in 6 patients, false-positive in 7 patients, and true-negative in 29 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET scanning were 100%, 81%, 46%, and 100%, respectively. We conclude that FDG-PET scanning is useful for prediction of therapy outcome in irradiated HNSCCs. No biopsy is needed for at least 1 year if an FDG-PET scan is negative. If the scan is positive and the biopsy is negative, decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.

18F-fluorodeoxyglucose positron emission tomography as a diagnostic tool for malignancy of adrenocortical tumours? Preliminary results in 13 consecutive patients.

DESIGN: This study is a preliminary report on 18F-fluorodeoxyglucose (18F-FDG) uptake for the characterization of hypersecretory or non-hypersecretory adrenocortical masses in patients without known neoplastic disease, thereby minimizing the presence of adrenal metastases, and without phaeochromocytoma, in comparison with computed tomography (CT) scanning and with iodocholesterol scintigraphy. METHODS: Thirteen consecutive patients with an adrenal mass scheduled to have surgery, underwent hormonal exploration, a CT scan for tumour size measurement and an 18F-FDG positron emission tomography scan. Eleven of these patients also had unenhanced density measurement at CT scan and iodocholesterol scintigraphy. RESULTS: CT-scanned adrenal masses ranged in size from 2.2 to 10 cm; attenuation value was <10 Hounsfield units (HUs) in two cases and >10 HU in nine. All benign lesions demonstrated iodocholesterol uptake. In the case of malignant tumours, results were non-homogeneous: no uptake, uptake and non-informative scintigraphy. All patients with an adrenocortical carcinoma had positive adrenal 18F-FDG uptake (n=3), one had a liver metastasis with positive 18F-FDG uptake, one showed 18F-FDG uptake in an adrenal metastasis from an unknown primary kidney tumour. All patients with a benign adrenocortical lesion had negative 18F-FDG uptake (n=9). Patients' lesions were hypersecretory (n=5), or non-hypersecretory (n=8), regardless of the pathology. CONCLUSION: This short preliminary study indicates that 18F-FDG gave a correct classification of tissue characterization with accurate identification of malignant lesions, as well as the disease stage (metastasis or primary). These promising preliminary results on adrenocortical lesions, seldom studied with 18F-FDG, are to be confirmed in larger series.