[en] Full text: Amendment 49: Amendment 49, 8th february 2006, excludes from the monopoly of the Brazilian Government the production, the commercialization and the use of short half-life radiopharmaceuticals for medical, agricultural and industrial uses. The most recent modification of the Brazilian Constitution was gave for the alteration of the writing in the ''alinea b'', addition of a ''alinea c'' to the interpolated proposition XXIII of the caput of article 21 and for the new writing given to interpolated proposition V of the caput of article 177. Since its publishing a great effort of all regulatories agencies in Brazil have been made looking for the harmonization of national laws bu the Brazilian Nuclear Energy C omission, Health Surveillance Agency and Brazilian Pharmacopoeia. The growth of PET-technology and consequently the use of FDG-18 and the radiopharmaceuticals in general, request a specific regulation. This regulation must be supported in the tripod: security, effectiveness and quality (FINN, 1999). In the United States, the radiopharmaceuticals are regulated under a number of agencies, because they are radioactive materials, and also are prescribed as medicine, being administered to human being. Finn (1999) alert, however, that an explicit need for the specific regulation. This necessity can be demonstrated by the signature in 21 november of 1997, in form of law, of the ''Administration Modernization Act'' (FOOD AND DRUG ADMINISTRATION MODERNIZATION ACT, 1997) applied to the Food and Drug Administration (FDA). This act, in its structure, commands that the FDA, develops practical procedures and good manufacture practice for radiopharmaceuticals, including that used in PET. In Europe, the regulations (registration and production) is made by the publishing of various ECC rules (the first was in 1965's) that are published in the form of Directives and Decision. To date tere have been 33 Council Directives, one Council Decision and one Council Regulation. In order to clarify these, numerous guidelines have been published: 11 quality guidelines; 10 biotechnology guidelines, 7 pharmacotoxicology guidelines, 10 clinical guidelines (General), 12 clinical guidelines (Therapeutics) and 3 information on medical products. Post-amendment Period: In Brazil, the first steps had started to be taken from this year. The first one of them, was the creation of the radiopharmacy subcommission, of the Brazilian Pharmacopoeia, responsible national agency for establishing the quality requirements that the medicines/drugs must obligatorily obey. These requirements include all the components used in the manufacture of medicines/drugs. Another action that deserves prominence, was the accomplishment of the ''I Workshop on Radiofarmacos'', carried through Anvisa/CNEN (National Health Surveillance Agency/Brazilian Nuclear Energy Commission), in an attempt of free-cooperation in search of parameters. Beside this others initiatives are being taken and the PUCRS (Pontifical University Catholic of the Rio Grande Do Sul) in partnership with the CRCN-NE (Regional Center of Nuclear Sciences of Northeast) and Brazilian Pharmacopoeia is in advanced period of training to promote the I Course of Specialization in Radioparmacy. However, Brazil still very behind in technician-legislative terms, and does not have any regulation for radiopharmaceuticals production yet. Prospective: An extremely important point in regards to radiopharmaceuticals is the education in radiopharmacy. As the production was always private of the CNEN the formation was always incubency of the same one, however, with the opening of the monopoly in addition of the market, the demand will be increasing. Besides, there is no course in Brazil that's teach radiopharmacy themes, even in the universities. As well an absolute lack of qualified professors, generates a preoccupying reality and that must be reviewed. However, nothing of concrete until the present moment really exists. Conclusion: For years radiopharmaceuticals have been produced in Brazil, without any specific regulati on. The evolution of PET radiopharmaceuticals in general, has introduced a new class of drugs that requires specific regulation, production facilities and the most important, qualified professionals. Even in Brazil there are no technician-legislative and any regulation a concerted effort by the various regulatory agencies has to be made to achieve a safe and effective methodology (regulation) and in this way, permit Brazil radiopharmaceutical production. Besides, is necessary introduce the theme radiopharmacy in the pharmacy schools programme, even in the post-graduated course and in this way, amplify the discussion. In fact, these actions will just minimize the problem stabilished in Brazil, but some thing has to be done and a more integrated work, including the Ministry of Health should be proposed. (author)

[en] Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, without invasive A-V difference data it provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. The aim of this study is to apply PET in combination with SI methods in an animal to simultaneously quantify substrate metabolism in specific tissues and the WB. Methods and materials: Animals: Seven white New Zealand rabbits (Mean ± SE 3.7 ± 0.1 kg;) were studied. After 14 hours of fast, they were surgically prepared by tracheotomy and implantation of catheters into carotid artery (Ca), jugular vein (Jv), and right femoral vein (Fv) under anesthesia. PET Imaging: The animal was placed in supine position in the gantry of a PC-4096 PET camera. Transmission images (5 min.) with a rotating pin source containing fib ⁶⁸Ge were acquired with the central tomographic slice positioned to include both hind limbs (HLs). Each animal received C¹⁵O₂ inhalation and was imaged for blood flow (BE) rate in HL muscles. Then, ¹⁸FDG (∼ 8 mCi) was injected into the animal through jugular vein, followed by serial PET images of muscle glucose metabolism (GM) for 90 min. Primed constant infusion of [6,6, ²H_]-glucose (0.8μmol/kg/min, priming 64umol/kg) was conducted simultaneously. Plateau level blood samples were taken from the Ca and Fv for WB and HL GM. Stable Isotope Measurements: The whole body glucose metabolic rate and the plasma glucose kinetics are calculated according to the conventional stable isotope steady state kinetics model. Q=i(E,/EP-l) where i is the infusion rate of stable isotope labeled [6,6, ²H₂]-glucose, E₁ and E_P are the isotopic enrichments of [6,6, ²H₂]-glucose in infusate and plasma under steady state conditions. The hind limb glucose metabolism was also measured using stable isotope tracer and tracee difference across the hind limb. WB GM determined by SI was 2.54 ± 0.22 mg/kg/min and GM in the right HL measured by A-V difference of ST was 0.77 ± 0.12 mg/leg/min. Based on muscle mass in HL (199 ± 7.8 g), LM GM (μg/g tissue/min) was calculated to be 3.40 ± 0.46 by St and 3.64 ± 0.22 by PET (N.S; paired t-test). BF to HL muscle determined by C¹⁵O₂ inhalation was 0.059 ± 0.01 ml/g tissue/min. Discussion: The two in vivo methods provided comparable quantitative information on muscle protein metabolism. PET measurements have the advantage of less invasive than A-V difference methods using SI, but it does not provide the information on whole body glucose disposal rate. Therefore combined SI and PET would provide more complete picture of whole body and regional glucose metabolism in vivo. Conclusions: PET-ST is a non-invasive approach to simultaneously quantify WB and muscle GM without biopsy, hence a powerful tool for human studies under various physio-pathophysiological conditions. (author)

[en] Full text: Recently, a new PET-Cyclotron facility has been built in Buenos Aires, Argentina. It consists mainly of a 11 MeV self-shielded cyclotron, a radiochemistry laboratory, a quality control laboratory and a state of the art PET-CT scanner. In the current work we describe the diversity of issues which had to be addressed in order to set up in operation this facility in Argentina. Since the PET market is still in its infancy in developing countries, local representatives of international vendors lack experience in providing adequate support during site planning, equipment installation and commissioning. Installation crews are mostly foreign, making scheduling of related tasks difficult and often fragmented due to overseas personnel availability. Local nuclear regulations include PET-cyclotron facilities in the same category as a nuclear power plant, making nuclear safety requirements difficult to meet and add to increased installation and operation costs. In addition, personnel licensing and regulatory documentation generation are demanding processes in this context. Harmonizing local clean-area codes with nuclear safety codes was also challenging since contradictions were often found between them. Short Half-life radiopharmaceuticals in general and Fl 8-FDG in particular are still not included in the Argentine Pharmacopoeia, so quality control procedures are still in debate. All the mentioned factors resulted in increased efforts and responsibility for the facility personnel and local contractors, adding to installation costs and completion time. (author)

[en] With the increasing application of F-18-fluorodeoxyglucose (FDG) positron emission imaging, there has been an evolving appreciation for the range of normal variants and the realization that false- positives can lead to serious consequences. One of the most common causes of a false-positive study is the uptake of FDG in areas of brown adipose tissue. BAT is generally present in deep cervical regions, including the supraclavicular areas, the interscapular and paravertebral regions, and areas near large vessels. Areas of involvement are often spatially closely related to important lymph node groups in the neck, axilla, and upper mediastinum, making critical differentiation difficult. The uptake of 18F FDG in brown adipose tissue (BAT) limits the ability of a PET scan to detect the sites of viable disease. Many studies have been done after premedication with Diazepam (benzodiazepines) to reduce the uptake of FDG by brown fat. But they are of limited value. Thus, it would be ideal if a drug could completely reverse the brown fat uptake and thus aid in proper management of the patient. The aim of this study is to see if by giving a single dose of a beta-blocker such as 'Ciplar' (Propranolol) 40 mg, 30 minutes prior to the FDG injection will help in reduction of brown fat uptake of 18F-FDG or not. Materials and Methods: Patients who were referred for a PET scan, either for a pretreatment or a post treatment evaluation and who showed FDG uptake in brown adipose tissue (BAT) were taken up for this study. The total number of patients was 14. A repeat PET scan was done after a gap of at least 48 hrs after the first study. The patients were advised to keep themselves warm with adequate warm clothing on the day of the second study. 40 mg of 'Ciplar' (propranolol) was given orally 30 minutes prior to the 18F-FDG injection. A whole body PET scan was performed on a dedicated whole body PET scanner (ADVANCE, GE Medical Systems, Milwaukee, WI.), using attenuation correction with 68-Ge external pin sources. Results: All patients showed absence of uptake of FDG in BAT, post propranolol. Discussion: Intense FDG uptake in BAT can lead to false positive FDG PET findings. BAT is known to exhibit increased glucose uptake when the sympathetic nervous system is activated by cold stimulation. BAT has rich adrenergic innervation. BAT acts as a thermogenic organ by producing heat to maintain body temperature especially in young individuals. BAT requires glucose as a source of adenosine triphosphate (ATP). This ATP is required for fatty acid oxidation, which is the main mechanism for heat production. In this study, we demonstrated that the intense FDG uptake in BAT can be successfully eliminated by giving 40 mg of propranolol orally 30 minutes prior to the 18-F FDG injection. Propranolol is a non- selective beta-adrenergic receptor blocking agent. It has no other autonomic nervous system activity. It is rapidly and completely absorbed from the gastrointestinal tract and undergoes extensive first-pass elimination due to its high hepatic clearance. Conclusion: Propranolol reduces the uptake of 18F FDG in BAT and thus improves the accuracy of PET imaging. (author)

[en] Metastases of testicular cancer almost always spread in insidious ways and are often diagnosed in an advanced stage. In patients with this kind of neoplasm, PET with [F-18] fluorodeoxyglucose (FDG) is more sensitive and specific than the CT for detection of metastases. This value should increase if we co-register PET and CT and then fuse these images. In literature we have found only a few studies describing the value of combined PET/CT studies made by the use of FDG in this group of patients. The aim of this study is the retrospective comparison of the CT and PET/CT in the diagnostics of testicular metastases. Material Methods: In the time between March 2003 and December 2006, 126 studies were made to diagnose testicular cancer. We selected 83 studies in which we have complete information about imagining techniques such as CT with contrast media and PET/CT. PET studies were made by using the Siemens Biograf LSO scanner according to typical PET protocol. We compared the results of the particular methods of diagnostics, performing patient to patient analysis with follow up. Results: In 55 cases (66,26%) PET/CT and CT gave consistent results. There were 32 negative PET/CT results (38,55%) and 26 CT negative results (31,32%). There was 15 patients with negative results of PET/CT and CT. In 8 patients (9,64%) PET/CT positive results corresponded with the negative CT results. In 6 patients (75%) from this group follow up confirmed PET diagnosis. In 20 patients (24,1%) CT positive results corresponded with the negative PET/CT results. There were 5 false negative PET/CT results (25%) in this group. Conclusion: PET/CT was found to be the most valuable tool for detection of testicular cancer metastases additionally giving exact information about its localization. There is the a need to conduct a prospective study to assess the value of the PET/CT in the diagnostics of testicular cancer in connection with histopathology. (author)

[en] Background: In neuroendocrine tumours (NET) workup it is often difficult not only to visualize but also to co-localize anatomically the lesions. The receptor scintigraphy allows to image the NETs with the receptor overexpression. NETs usually overexpress the subtype 2 of somatostatin receptors (SSTr). Therefore many somatostatin analogs like: ¹¹¹In-octreotide were used to visualize these tumors. The sensitivity of Somatostatin Receptor Scintigraphy (SRS) for NET is 70-90%.Behe and Maecke introduced hydrazinonicotinamide (HYNIC) as a bifunctional chelator for ^99mTc labelling of octreotide and Tyr3-octreotide (TOC) with high efficiency (1). The ^99mTc-HYNIC-TATE is the new preparation to the detection for NET. The Tyr3-octreotate (TATE) somatostatin analogue differs from TOC in that the terminal threonine replaces threoninol. The terminal threonine results in a higher receptor binding and better internalisation, with the consequence that tumour uptake of the tracer is intense. Aim: The aim of the study was to assess the efficacy of the new ^99mTc-HYNIC-TATE preparation in the NETs imaging with the overexpression of somatostatin receptors (SSTR). Methods and material: The ^99mTc-HYNIC-TATE preparation produced by OBRI POLATOM (Poland) was used to assess 81 patients with clinical, pathological or laboratory proof for neuroendocrine tumour. The scintigraphy was acquired on the double -head gamma camera in 10 min, 2-3 h and 24 h after intravenous injection of ^99mTc-HYNIC-TATE. The injected activity was 550-740 MBq (15-2OmCi). The following views were gathered: planar AP, PA and SPECT of the head, chest and abdomen. All patients were scanned (chest and abdomen) routinely with 16-row CT. The image processing and fusion was performed on the dedicated workstation Hermes Nuclear Diagnostic (Sweden). Results: ^99mTc-HYNIC-TATE confirmed the presence of NET in 66 patients. In 10 patients the thyroid cancer was found and in 5 subjects the acromegaly was diagnosed. The fused images of receptor imaging and CT allowed to precisely localize the pathological tracer uptake and to detect the tumour in 83% patients. Discussion: Endocrine tumours are heterogeneous group of neoplasms. ¹¹¹In-Octreoscan has been the 'gold standard' in the imaging diagnosis of endocrine tumors. ^99mTc-EDDA/HYNIC-octreotate scans showed similar physiological biodistribution of the tracer in comparison to ¹¹¹In-Octreoscan SRS. In vitro studies with somatostatin receptors revealed that TATE, shows 14- to 17-fold higher affinity for SSR2 than octreotide and eight- to tenfold higher affinity than TOC. ^99mTc-EDDA/HYNIC-octreotate whole body scans revealed more metastatic lesions, with higher target/non-target count ratios. In comparison to CT, ^99mTc-EDDA/IIYNIC-octreotate appeared to be a more sensitive modality in the detection of the primary lesions and liver and abdominal lymph node metastases. The development of image fusion SRS and CT or MRI will significantly improve the early localization of carcinoids. In our study ^99mTc-EDDA/HYNIC-octreotate had a high accuracy for detection of the endocrine tumors. Fusion imaging SPECT and CT scans in diagnosis of the endocrine tumours enables both pathological and physiological changes to be localized precisely. Conclusion: The ^99mTc-HYNIC-TATE preparation is useful in NET imaging. The image fusion with the CT data enables to precisely co-localize the lesions with pathological uptake. (author)

[en] The proper identification of an epileptic focus is very often prerequisite for a successful surgical management of epilepsy. There have been great advances in the identification of epileptic foci by using modern imaging methods, namely positron emission tomography (PET) and magnetic resonance imaging (MRI). PET scanning with 2-[¹⁸F]fluoro-2-deoxy-D-glucose (2-FDG) has been used for pre-surgical evaluation of epileptic patient and identification of the fucus. An interictal epileptic focus is identified by the brain hypometabolic activity in the focus and surrounding brain area when 2-FDG and PET are used. These hypometabolic areas are often also identified by MRI when a structural lesion is present

[en] The development of this work consist of the implementation of Computer Axial and Positrons Emitted Tomography Acquisition Protocols using Fluordesoxiglucose (I 8F-FDG) to obtain images compatible with the registration as it is too sensitive to the patient position, breathing, observing pathology and election of adequate variables in the respective tomographs. It was proved through the use of registration software that the application of protocols succeed in lining up images in a more useful and reliable way because outside the brain the co-registration is more difficult.In this way we try to improve the co-registration of imagings with a prospective protocol of acquisition. (author)

[en] Full text: In Hungary PET examinations started about 10 years ago meanwhile PET/CT examinations have been carried out since 2005 with two new PET/CT centers and two medical accelerators (baby cyclotrons). The upcoming PET/CT applications represent the highest patient exposures in medical diagnostics with potentially the highest staff exposures as well. The radiopharmaceutical, which is solely F-18 FDG in the actual Hungarian practice is transported in sealed ampoules in doses between 5-20 GBq. The dispensing of the doses and filling of the syringes are carried out in automatic dedicated hot cells. The glucose labelled with F- 18 radioisotope (half life is 1 10 minutes) with a dose 370 MBq (for average patient) filled into a syringe is injected into a blood vessel of the patient. Then, the patient becomes the most significant radiation source of nuclear medicine. According to our measurements, the dose rates rise between 30-50 μSv/h at I m from the patient surface. The radiation is a very highly penetrating annihilation gamma radiation with an energy of 511 keV. The appropriate level of shielding needed should be determined amongst the active patients (two are waiting for examination, one is examined, 1 or 2 are waiting after examination) and the members of the staff and the inactive environment. The task is an optimalisation process, since the reasonable value of dose constraint should be decided. For lack of relevant national regulation, it is the task of our Institute to determine the appropriate radiation protection requirements for the PET/CT centers. One of the two new Centers started in 2005 has been surveyed for months. Altogether 1092 measurements were carried out. On the base of measurements, it is proven that I mSv/year effective dose can be introduced as dose constraint for each separable source of exposures to the staff, namely for the administration of the radiopharmaceuticals, the radiation of active patients and the PET/CT examination. The requirement of dose constraint can be fulfilled if 15-20 cm thick normal concrete walls are built around the active areas. The shielding of the doors and the lead equivalency of the lead glass between the examination and operator rooms should be planned against CT radiation only (1.5 mm Pb and 2.2 mm Pb_ekv respectively). (author)

[en] Quality Health care results from translating fundamental bench discoveries and making them available to patients. During the past decade, 'molecular imaging' has emerged both as a new tool/technology and as a research and clinical discipline. Molecular imaging is an interdisciplinary approach involving biologist, physicist, physicians, mathematicians, radio chemists and other specialists who have joined forces for better understanding and visualizing of both normal physiological processes and the molecular processes preceding the morphological manifestations of disease in vivo. It is interesting to note, that despite major advances in imaging technology, cancer mortality has remained largely unchanged over the last three decades. Imaging has thus far enabled us to look through a magnifying glass at disease processes but has failed to dramatically influence disease outcomes. Emerging data suggest that molecular PET imaging is about to change this situation. Quality assurance is based on monitoring, measuring, evaluation, verification and recording of quantities, parameters and facts significant from the point of view of Radiation Protection. Quality assurance programs shall be established that provide, as appropriate: adequate assurance that the specified requirements relating to protection and safety are satisfied and quality control mechanisms and procedures for reviewing and assessing the overall effectiveness of protection and safety. The Republic of Moldova with the support of the International Atomic Energy Agency perform the quality assurance and quality control procedures in the frame of the Technical Cooperation Regional Projects RER-6-012 ''Quality Assurance and Quality Control in Radiation Oncology'', and RER-6-011 'Thematic Program on Nuclear Medicine'. The Ministry of Health and Social Protection carry out the National Project 'Ensuring Radiation Safety and Protection of the Patients' the principal goal being the Quality Assurance and Quality Control in Radiotherapy. In 2005 started the implementation of the National Project 'Radiation Protection, Quality Assurance and Quality Control in the Nuclear Medicine'. Objectives of the Quality Assurance include: improvement in the quality of the diagnostic information, use of the minimum radionuclide activity that ensures the production of the desired diagnostic information, effective use of available resources. The quality of a practice is to fulfill the expectations and demands from the patient, the clinician, yourself. The primary service of the Quality Assessment includes the communication with the client (patient, clinician). The final judge of any nuclear medicine practice is a clinical audit to determine the correctness and impact of the decisions made with respect to any method and process. e.g. internal audit, inspections by the Regulatory Authority