[Results of testing of MINISKAN mobile gamma-ray camera and specific features of its design].

The main results of engineering, biomedical, and clinical testing of MINISKAN mobile gamma-ray camera are presented. Specific features of the camera hardware and software, as well as the main technical specifications, are described. The gamma-ray camera implements a new technology based on reconstructive tomography, aperture encoding, and digital processing of signals.

[Evaluation of the quality of radiopharmaceutics]. / Otsenka kachestva radiofarmatsevticheskikh preparatov.

The authors considered the interrelationship of clinical requirements and analytical indicators of quality for a group of pharmaceuticals: radionuclide purity (by the criteria of dose load and the quality of visualization); radiochemical purity (interrelationship with a necessary level of accumulation in investigated organs); chemical admixtures (by the criteria of safety and influence on the diagnostic quality; clinical criteria of quality were under discussion); a coefficient of differential accumulation in the system: organ under study-adjacent tissues; specificity; indices of pharmacokinetics, etc. Correct and all-round evaluation of RP quality on the basis of the above criteria determines, to a great extent, a choice of a labeled compound to be used in a specific radionuclide diagnostic method.

[The clinical quality evaluation of radiopharmaceutical preparations for diagnostic use]. / Klinicheskaia otsenka kachestva RFP diagnosticheskogo naznacheniia.

The authors issued some recommendations for assessment of new radiopharmaceuticals (RP) at the stage of clinical trials. The most decisive thing is to determine the clinico-diagnostic efficacy of a radiopharmaceutical and its safety. Direct extrapolation of the results of experimental investigation of biodistribution of labeled compounds on man was shown to be fraught with serious errors. Differences in RP pharmacokinetics necessitate a planned, methodologically correct and clinically substantiated study of a RP in selected groups of patients taking into account the functional purpose of a drug. The assessment of RP quality is based upon a study of functional suitableness resulting from pharmacokinetic data and the determination of optimum methodological conditions and safety of a new RP, including the calculation of radiation a patient is exposed to during a diagnostic procedure. The stages of clinical trials are given in detail, their unification is aimed at raising their quality and improved clinical assessment of a RP.

[Metabolic effect of lipostabil-forte]. / Metabolicheskii éffekt lipostabila-forte.

Effects of lipostabil-forte containing unsaturated fatty acids on serum lipid concentrations, plasma and erythrocyte lipid and phospholipid fractions, immunoreactive insulin and thyroidal hormone levels were studied in 30 patients with coronary heart disease. During the therapy of all the patients within 1 month and occasionally 3 and 6 months, there was a statistically significant reduction in serum triglycerides, an increase in relative erythrocyte phospholipid levels and in plasma and erythrocyte phosphotylcholine, as well as reversal of hyperinsulinemia and improvement of thyroid function.

[Comprehensive diagnosis of cancer of the ovaries]. / Kompleksnaia diagnostika raka iachnikov.

Combined examination of 96 patients with different gynecological diseases included methods of ultrasound tomography, scintigraphy of the small pelvis with 99mTc-pyrophosphate, immunoscintigraphy and radioimmunoassay for determination of the blood level of CA 125. New diagnostic methods for ovarian cancer using 131I labeled monoclonal antibodies and an algorithm for data processing were developed. Of 96 patients 39 had ovarian cancer, 6 patients--uterine tumors, and 51 patients (controls) with nontumorous and benign lesions of the ovaries and uterus. The diagnostic effectiveness of these methods was determined by the indices of sensitivity, specificity and accuracy. The radioimmunoassay for determination of CA 125 possessed the highest sensitivity, ultrasound tomography showed the highest specificity and accuracy. Immunoscintigraphy with Imacis-2 was shown to possess the highest diagnostic effectiveness and unique informative value. An optimum algorithm for the use of the above methods in patients with suspected ovarian cancer was proposed on the basis of these investigations.

[Internal irradiation doses in patients during the diagnostic use of colloidal radiopharmaceutics]. / Dozy vnutrennego oblucheniia patsientov pri diagnosticheskom ispol'zovanii kolloidnykh RFP.

The assessment of the human organs and body systems exposed to radiation was based on the investigation of colloidal radiopharmaceuticals employed in the USSR for liver and spleen visualization. Seven radiopharmaceuticals (functional analogs: 3 were imported to the USSR, 4--made in this country) were investigated. Pharmacokinetics of the agents was studied by a human counter that permitted obtaining quantitative data on their distribution and elimination from the body. A computerized program based on the heterogeneous model of a "standard" man. Dose calculation results have shown that the critical organ for all investigated radiopharmaceuticals is the liver, the radiation dose in it being at 90-120 microSv/MBq and the mean effective equivalent dose at 14 +/- 1 microSv/MBq.

[Complex radionuclide diagnosis of tumor lesions of the bones]. / Kompleksnaia radionuklidnaia diagnostika opukholevykh porazhenii skeleta.

A complex examination of 320 patients with breast tumors of varying degree of advancement was carried out. Also, the data on examination of 20 cases of fibrous-cystic mastopathy and 40 healthy females were analysed. Similar studies were conducted in 20 cases of acute and chronic osteomyelitis, 14--tuberculosis of bones and joints, 63--rheumatoid arthritis and 36--Bekhterev's disease. Pyrphotech, Tc99m; pyrophosphate, Tc99m and diphosphonate Tc99m were used in carrying out scintigraphic examination. Parathyrin, prolactin, carcinoembryonic antigen (CEA), alpha-fetoprotein and ferritin were assayed in patients' blood serum. Tumor dissemination to bones was matched by a significant rise in CEA and prolactin levels. However, these parameters were normal in patients with non-tumor skeletal pathology. No significant rise in ferritin and alpha-fetoprotein were recorded in all patients. The specificity of the said complex examination, including osteoscintigraphy and blood plasma parathyrin assays in breast cancer patients, was 79%.

[Pharmacokinetics of 99mTc-technephore in man]. / Farmakokinetika 99mTc-tekhnefora u cheloveka.

Assessment of the pharmacokinetics of 99mTc-technephore in the human body was based on an analysis of the results of its study in 43 out of 87 patients with neoplasms of non-osteogenic origin (breast cancer, lung cancer, reticulum cell sarcoma, etc.). Radiometry by means of a counter of the whole human body radiation was performed shortly after the drug administration with one-hour intervals for 4-5 hours. Methods of blood radiometry and osteoscintigraphy were employed. The study showed that the redistribution of the drug occurred in the first minutes after its injection, chiefly between the 2 volumes: the skeleton and the urinary system. The value of its activity in the bladder by the 3rd hour was 59% of the administered amount. Clearance of the blood was rapid and its radioactivity by the 3rd hour was no more than 6% of the administered amount. The amount of the drug by the same time was within 31-32%. A high gradient of differential accumulation of the drug in the osseous tissue and the adjoining tissues (the skeleton/background-312%) made it possible to get high-quality scintigrams. Investigations of the patients with the help of gamma-chambers and scanners were initiated 2.5-3 hours after the drug injection. The sensitivity and specificity of 99mTc-technephore were similar to those of other phosphatic and phosphonate radiopharmaceuticals: 96 and 12%. A conclusion was made that the drug could be used in clinical practice as an osteotropic agent.

[Osteoscintigraphy in the diagnosis of rheumatoid arthritis and Bechterew's diseases]. / Osteostsintigrafiia v diagnostike revmatoidnogo artrita i bolezni Bekhtereva.

The paper is concerned with an analysis of the results of clinical and radionuclide examination of 36 patients with ankylosing spondylitis (AS) and 63 patients with rheumatoid arthritis (RA). The period of observation lasted from several week to 5 yrs. Osteoscintigraphy was performed using labeled agents. The data obtained coincided with pain sensations whereas the correspondence of painful zones and x-ray findings was noted in 39% of the patients. In RA hyperfixation of the drug was determined mainly in small and big joints (130-250%) in 92% of the patients coinciding with the pain syndrome and with X-ray findings in 38% of the cases only. Radionuclide signs of therapeutic efficacy were noted in 56% of the patients with AS and in 82% of the patients with RA. Radiation exposure of the bone marrow in osteoscintigraphy and x-ray investigation was defined (4.1 and 14.4 microGy). A radioimmunoassay showed elevated content of PTH in 67% of the patients with AS up to 4.0 +/- 0.5 iu/ml.

[Methodological aspects of bone marrow research using 111In-citrin]. / Metodicheskie aspekty issledovaniia kostnogo mozga s 111In-tsitrinom.

A study of 111In-citrin distribution and kinetics in the body of patients without hemopoietic disorder showed the accumulation (up to 20%) of the injected drug in the bone marrow. Organ fixation, elimination and other pharmacokinetic indices confirming 111In-citrin functional applicability for investigation of the red bone marrow were determined shortly after intravenous injection and in 24 h using a total body meter. These data formed the basis for the calculation of radiation exposures and the solution of methodological problems related to a radionuclide study of the bone marrow in cancer and leukemic patients. 111In concentration in the pelvic bones determined with the help of the total body meter, reflected the total red bone marrow functional activity and was in reverse correlation with a RP elimination value. Total body scintigraphy 24 h after the drug administration made it possible to visualize the bone marrow distribution in the body and to reveal signs of general or local disorders of bone marrow functional activity in leukemias or malignant tumors after combination therapy.

[Radiation doses to patients after the use of 99mTc-pyrophosphate and 113mIn-indifor]. / Dozy oblucheniia patsientov pri ispol'zovanii 99mTc-pirfotekha i 113mIn-indifora.

The doses of irradiation of patients during the use of 99mTc-pyrphotech and 113mIn-indifor have been defined on the basis of their pharmacokinetics. The data has been obtained with the use of radiometer of human radiation, the method of organs screening during radiometry, and of the gamma-camera and blood samples radiometry. The calculations have been performed in accordance with the known method based on the heterogeneous model of the "standard" human. In the dose calculations for bone tissue and for the red marrow the dosimetry model is used and the values of absorbed fractions recommended by the ICRP. The absorbed and equivalent doses of irradiation of different organs and systems in human organism have been defined. The required values of quality index have been calculated using the spectrum of absorbed dose on the scale of linear transfer of energy for all radiations of the analysed nuclides. The obtained values of efficient equivalent dose are 8.6 and 16 MeV/MBq for 113mIn-indifor and 99mTc-pyrphotech correspondingly.

[Pharmacokinetic substantiation of the use of 111In-citrate in bone marrow studies]. / Farmakokineticheskoe obosnovanie ispol'zovaniia 111In-tsitrina dlia issledovaniia kostnogo mozga.

Soviet radiopharmaceutical 111In-citrin has been studied to define its possible application for marrow visualization. 111In-citrin has been shown to accumulate in the red marrow, parenchymal organs and to be excreted from animal organism by urinary system predominately. 111In-citrin has advantages in defining the nuclide concentrations in marrow blood and serum as compared with colloid preparations and 111In-chloride. 111In-citrin is supposed to be an adequate radiopharmaceutical preparation for visualization of the red marrow.

[Use of radioactive fatty acids for evaluating the processes of beta-oxidation of fatty acids in the body]. / Primenenie radioaktivnykh zhirnykh kislot dlia otsenki protsessov beta-okisleniia zhirnykh kislot v organizme.

The pharmacokinetics and metabolic features of I-radionuclide labelled derivatives of aliphatic carboxylic acid were studied in experiment. The authors show the possibilities of nuclear medicine in deriving information on the activity of fatty acid beta-oxidation in the animal liver and body using compounds with C4 = C11 aliphatic chain locus.

[Pharmacokinetics of 113mIn-indifor]. / Farmakokinetika indifora 113mIn.

113mIn-indifor pharmacokinetics was studied in 82 patients with malignant tumors (breast and lung carcinoma, reticulum cell sarcoma) in the first 2 hrs after i. v. injection. The drug redistribution in the first minutes occurred mainly between the osseous tissue and the urinary system, the value of radioactivity in the urinary bladder by the 1st hour was 50% of the injected value making it possible to visualize the kidneys. A high gradient of the drug accumulation in the osseous tissues and the adjacent organs and tissues made it possible to obtain high quality scintigrams. Radiation exposure of the skeleton was 7.0 mu Gy/MBq, that of the urinary bladder 61 mu Gy/MBq.

[Kinetics of hepatotropic radiopharmaceuticals]. / Kinetika gepatotropnykh RFP.

A study was made of the biological distribution of 131I labeled stains and 99mTc labeled iminodiacetic acid derivatives in 153 patients of whom 98 suffered from jaundice of different genesis. Significant differences of their behavior in the human body depending on the chemical structure of the compound were revealed. Blood clearance for the iminodiacetic acid derivatives was 1.5-2 times as high as compared to that for the labeled stains. The rate of transit via the hepatocyte was the highest in 99mTc-MESIDA (USSR) 99mTc-DIDA and 99mTc-TIDA. The rate and volume of the renal excretion of the radiopharmaceutical depended on the main substance molecular structure. Retarded blood clearance lowered excretion of the radiopharmaceuticals by the liver and their considerable excretion with urine were observed. The Soviet radiopharmaceuticals 99mTc-MESIDA and 99mTc-BUTILIDA by their pharmacokinetic characteristics and quality were in no way inferior to the best foreign analogs.

[Radionuclide diagnosis of ovarian tumors]. / Radionuklidnaia diagnostika opukholei iaichnikov.

The authors present a method with the use of 99mTc-pyrophosphate for differential diagnosis of malignant and benign ovarian tumors. A total of 46 patients were examined. Of these, the sample hyperfixation in the zone of malignant ovarian tumors with the rate of differential accumulation of 200-260% was observed in 7. In benign tumors and inflammatory ovarian changes, radiopharmaceutical hyperfixation was either not observed or it did not exceed 130%. Diagnosis in all the patients was verified at operation with subsequent histological examination.