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[en] Whereas single photon tomography provides a new and rewarding dimension to conventional nuclear medicine, positron tomography makes a new original approach possible of the analysis in vivo of fundamental biological and physiological processes. The main object of both is the sectional representation of the distribution of a radioactive indicator injected into the body system; compared with conventional detectors (gamma cameras and scintigraphic systems) they provide much greater accuracy in localization. The characteristics of these two methods can be presented schematically by comparing their respective advantages and drawbacks

[en] The cyclotron facility, essentially for medical use, is far from being a simple establishment of a dedicated device to accelerate particles producing a beta plus emitter radioelement. The cyclotron site encompasses more over all necessary equipments for the production and the quality control of considered radiotracer that ¹⁸FDG is just one example. This facility is subject to strict standards in terms of radiopharmaceutical production, radiation level, pressure level and airflow resulting in the production of a drug submitted to the MA (Marketing Authorization). These multiple factors directly influence the final cost of the dose that remains to be reachable by the patient. The aim of this work is to estimate the cost of a dose of ¹⁸FDG to ensure financial viability of the project while accessible to the patient. The cost of the facility will entail the following: buildings and utilities, equipment and operational cost. This calculation is possible only if we define in advance the type of cyclotron, which is bound to the market needs in particular the number of PET facilities, the number of scans per day and the radioactive decay of radioelement. Our study represents a simulation that considers some hypothesis. We assumed that the cyclotron is installed in Sousse and that the PET facilities number (positon emission tomography) is 6 in which 4 are located 2 hours away. For a PET scan, the average dose per patient is about 350 MBq (5 MBq/kg) and the exam duration is about 45 minutes. Each center performs 10 tests per day. In terms of fees, we considered device and building's cost, facility amortization, consumables (target, marking accessories), maintenance, remuneration expense and the annual electricity consumption. All our calculations have been reported to the number of working days per year. The estimates were made outside the customs duties and technical assistance that may last up to 2 years. Requirements and needs were estimated at 5.4 curies per day. For accomplishing that, a non self-shielded cyclotron with energy under 20 MeV is required. The daily amount of such production is estimated to 4000 dollars. The numerous experienced scan daily have an immediate impact on the price of the dose because of their cost which vary between 80 $ (50 exams per day) and 200 $ (only 20 exams per day). Our estimated price, including the cost of technical support, is too close to the price fixed by two neighbor countries (Egypt and Jordan) which corresponds to 300 dollars for the dose. The daily number of doses taken will determine the financial viability. (Author)

[en] ¹⁸F-fluorodeoxyglucose (FDG) PET is a non-invasive imaging technique recommended for the management of both diffuse large B-cell and Hodgkin's lymphomas. This retrospective study investigated the value of FDG PET for initial staging and its prognostic impact on patients with mantle cell lymphoma (MCL). A total of 44 untreated MCL patients assessed by both conventional evaluations (CE) and FDG PET for initial staging were included. The maximum standardized uptake value (SUV_max) in the most intense pathological area was recorded for each patient. Disease status after chemotherapy completion was assessed according to the International Workshop Criteria (IWC) for non-Hodgkin's lymphoma (NHL) response and IWC+PET. FDG PET uptakes at diagnosis were abnormal in all cases. Compared to CT scan, nodal and extranodal sites were only detected by FDG PET. Due to insufficient sensibility for bone marrow (BM) and gastrointestinal (GI) involvement, FDG PET did not modify initial staging. Positive and negative predictive values of IWC+PET for relapse at 1 year were 62.5 and 100%. With a median follow-up of 21 months, only the International Prognostic Index (IPI) and IWC+PET modified both event-free survival (EFS) (p =.02 and.0001, respectively) and overall survival (p =.03 and.05, respectively) duration. When combining IPI and SUV_max at diagnosis, we were able to identify patients with low (29%; no relapse/progression), intermediate (42%; median EFS: 37 months) and high risk (29%, median EFS: 22 months) (p =.004). In MCL, FDG PET at diagnosis is complementary to CE, but BM and GI biopsies remain mandatory. IWC+PET criteria are highly efficient to identify patients with high risk for early relapse. Combining IPI and SUV_max may predict patient outcome and warrant further prospective investigations towards designing risk-adapted strategies. (orig.)

[en] Short communication

[en] A review is presented of data from the literature on the current state and application of positron emission tomography (PET) in neurophysiological research. The studies reported mainly include the determination of normal blood flow values, of the brain oxygen and glucose metabolism, and the effects of activation and deprivation processes. The method provides knowledge of intrahemispheric and interhemispheric relations that was unknown before the advent of PET. It also allows visualizing processes that could so far only be studied in animal experiments. (L.O.). 17 refs

[en] This thesis describes the measurement of brain-tissue functions in patients with movement disorders using positron emission tomography (PET). This scanning technique is a method for direct in vivo quantitation of the regional tissue content of positron emitting radionuclides in brain (or other organs) in an essentially non-invasive way. Ch. 2 outlines some general features of PET and describes the scanner which has been used for the studies in this thesis. Also the tracer methodology, as applied to data investigations of movement disorders, are discussed. Ch. 3 contains the results of the PET investigations which were performed in the study of movement disorders. The results are presented in the form of 12 papers. The main goals of these studies were the understanding of the pathophysiology of Parkinson's disease, Huntington's chorea, Steele-Richardson-Olzewski syndrome and special case reports. Ch. 4 summarizes the results of these publications and Ch. 5 concludes the main part of this thesis with a general discussion of movement disorders in relation to PET investigations. 697 refs.; 60 figs.; 31 tabs

[en] The Tunisian National Health Insurance Fund (TNHIF) has 186 practitioners and advisers (physicians, dentists and pharmacists) in the service of medical supervision. These advisers are distributed on three levels (regional, district and national). In the present paper we have discussed the CNAM support in the different types of oncology (FSD (Fully Supported Disorders), Hospitalization, the scans, the radiation therapy, specific drugs and treatment abroad). We begin by presenting expenditures by year and age group for FSD and hospitalization in the private and the public sectors. We then give the conventional packages for scans, radiotherapy: either for CLAM or CRAM. Daily benefits for the sickness leave and the disability will be presented briefly. Then we will give the administrative process for the approval of the commission for specific medication. The medical advice is based on certain criteria that will be explained in the paper. In certain cases definitive medical advice needs to call for the recommendation of a national commission and oncology or different experts. The spending trend of the TNHIF from 2001 to 2012 will be discussed. TNHIF generally considered Herceptin, Nexavar Erbitaux as the main drugs for targeted therapies. We present for the treatment cost and expenditure trends for the first drug from 2008 to 2012 as well as the estimation for 2013, which increases from one year to year. For the treatment with the second and the third drug we give the evolution of expenditure between 2010 and 2012. Cancer is a serious disease that requires a costly multidisciplinary support for the patients. This support has changed the prognosis survival (see cases of healing). The financial coverage of this support can never be supported by the family (whatever the wealth level) without any TNHIF support. The real gain in survival and expenditure control are closely related to awareness and early detection of the disease. TNHIF usually intervenes in the financing of care abroad as PET SCAN and nonfamily Allograft that we present the number attributed each year. We conclude with statistics on expenditures in cancer diseases: increased spending from one year to year (2010-2011), the number of cancer care abroad (2010-2011-2012) and at the end the number of PET tumour location. (Author)

[en] In PET, usually the data are precorrected for accidental coincidence (AC) events by real-time subtraction of the delayed window coincidences. Randoms subtraction compensates in mean for AC events but destroys the Poisson statistics. Furthermore, for transmission tomography the weighted least-squares (WLS) method leads to systematic biases, especially at low count rates. We propose a new open-quotes shiftedclose quotes Poisson (SP) model for precorrected PET data, which properly matches the first and second order moments of the measurement statistics. Using simulations and analytic approximations, we show that estimators based on the open-quotes ordinaryclose quotes Poisson (OP) model for the precorrected data lead to higher standard deviations than the proposed method. Moreover, if one zero-thresholds the data before applying the maximization algorithm, the OP model results in systematic bias. It is shown that the proposed SP model leads to penalized-likelihood estimates free of systematic bias, even for zero-thresholded data. The proposed SP model does not increase the computation requirements compared to OP model and it is robust to errors in the estimates of the AC event rates

[en] Describe a rare case of false positive in the study of lung nodules. Describes the case of a patient 73 years, smoker with non-calcified pulmonary nodule in the right upper lobe of 22 mm, as an incidental finding in chest x-rays and CT. Pulmonary sclerosing hemangioma is a benign neoplasm; radiologically described as a well-circumscribed pulmonary nodule that is preferentially located in the lower lobes and enhanced with contrast medium, which is not possible to differentiate a malignant tumor. The specificity of PET-CT for characterizing lung nodules, benign vs. malignant adequate but not 100% (E: 76% -83%). The most frequent causes of false positives are usually inflammatory, but less frequently, such as sclerosing hemangioma has already been reported in the literature. In lung lesions with positive PET study with biopsy necessary to rule out the possibility of a false positive