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Chemotherapy is an important method of antitumor therapy. Nephrotoxicity characteristic of many cytostatics, including platinum compounds, is a serious complication limiting the drug dose [4,5,7-9]. Platinum derivatives, in particular, cisplatin, are drugs of choice in the treatment of the majority of solid tumors. However, cisplatin induces a dose-dependent toxic damage to the kidneys [5,7,8,10].

The paper deals with a diagnostic informational and analytical system (DIAS). The system is based on the current concept of a dynamic model of nephro-urological clearance macroregulation under retention factors at the pre-, intra-, and postrenal levels during drug load tests. DIAS includes a package of dynamic renoscintigraphic techniques, as well as original software support. A system for parameters of renal clearance regulation has been developed, which is effective at nephro-urological screening and monitoring at all treatment stages for cancer patients. A two-detector chamber which permits the mounting of a detector at an angle to the patient's body is the optimum diagnostic apparatus for a cancer clinic. The use of functional tests makes it possible to examine the regulatory reserves for each kidney, followed up by the choice of adequate corrective measures to prevent renal failure during treatment. In some cases, DIAS monitoring frequently shows a higher sensitivity to the signs of latent renal failure than does routine clinical and laboratory monitoring. The effective radiation dose taken by a patient during a study by the DIAS technology aimed at reducing radioopaque doses is 100-150 times higher than that at an X-ray study and is an order less than during routine urinary tests.

The task was to develop a simple and effective method of radionuclide determination of separate clearance of the kidneys (SCK), i.e. separate assessment of secretory-excretory function of each kidney. The other earlier known methods of SCK determination were either methodologically incorrect or very difficult. A method of SCK determination intended both for gamma-chambers and standard radiographic units based on common renographic methods, was proposed. An algorithm for processing of measurement results was based on the generalization of the mathematical apparatus of circulation models usually employed for a study of the central and organ hemodynamics, and on its development for transitory nephrotropic radiopharmaceuticals (RP). An investigation of 21 healthy persons and 51 patients with renal tumors using 131I-hippuran showed that the proposed method possessed sufficient sensitivity for its clinical use. Advantages and shortcomings of the method were analysed. All the allowances were justifiable.

Some criteria for assessment of the adequacy of various radionuclide methods of determination of the separate renal clearance were proposed. Some methods were analyzed according to these criteria: one of them was proposed by S. U. Schlegel et al. and used in the paper by M. E. Karaev and R. N. Samedov, and the other one was proposed by V. Kh. Frenkel' and V. B. Shushkovskiĭ. Both methods were shown to be insufficiently substantiated from physiological and mathematical view-points. A method of assessment of the separate renal clearance in the form of a circulation model was proposed. It was based on the minimal possible number of simplifying allowances and made it possible to define the state of secretory-excretory (or filtration) function and the state of hemodynamics of each kidney as a result of single administration of a transit nephrotropic radiopharmaceutical.