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Physical status of 172 former cases of retroperitoneal tumors was investigated. As a result of treatment for cancer, former patients revealed changes in the urinary (62.5%), cardiovascular (25%) systems and gastrointestinal tract (71.5%). These indices, however, stayed within the morbidity rates in the total population.

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 increasing doses of 2.4-3.5 g/m2 ifosfamide, i/v, dropwise, were administered for 40 min, on days 1-5 each week, for 3 weeks, in 4 courses. Simultaneously, MESNA was given in a dose two-thirds of that of ifosfamide. The maximum single tolerable dose of ifosfamide was 3.2 g/m2. The dose of 3.5 g/m2 proved neurotoxic causing encephalopathy. The other toxic effects were stage III-IV neutropenia (47%), nausea and vomiting (91%) and weakness (33%). No clinical evidence of renal failure was attributed to the high dosage of the drug in the course of assays of biochemical components of the blood, blood- and urine-beta-2-microglobulins, N-acetyl-D-hexoaminidase (NAG) level in urine, creatinine clearance and complex renoscintigraphy data. On days 3-5, ifosfamide treatment was followed by increase in NAG and beta-2-microglobulin levels in urine which pointed to the toxic effect exerted on the epithelium of renal tubules. The antitumor effect was apparent in 5 (29%) patients for 6 months, which testifies to the high effectiveness of ifosfamide treatment for soft-tissue sarcoma.

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.

Different schemes of prospidin administration to 54 patients were evaluated. Stage IV paresthesia or renal derangements are limitations of prospidin treatment due to its toxicity. Rheovasographic studies established that disorders in vascular tension are responsible for paresthesia development. The best results were obtained with the administration of 300-400 mg every other day for 2-3 weeks. Schemes of combined administration of prospidin and cyclophosphamide and bleomycin were worked out (58 cases). Therapeutic effect was recorded in the treatment of melanoma, carcinoma of the lip, tongue, nasopharynx, salivary gland and skin. Prospidin, cyclophosphamide and radiation therapy were successfully used in the management of small cell carcinoma of the lung.

The results of combined radiodiagnosis of the urinary system in patients with renal tumors before and after nephrectomy were analyzed. Investigations included excretory urography and renography with the processing of the results of measurements by a common algorithm and on the basis of 3 mathematical models of RP body transport. The results were correlated with the findings of biochemical blood and urine tests and pathoanatomical investigation of the removed kidney. Ample potentialities of renography for the detection of latent renal insufficiency in the preoperative period and for accurate and exhaustive assessment of function of the urinary system were shown.

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.

Various mathematical models describing the process of transport of nephrotropic radiopharmaceutic drugs in the body of patients are used at present on a wide scale in processing the results of radionuclide studies of the urinary system functional status. The authors propose to give an objective quantitative assessment on the basis of a complex consisting of 3 mathematical models.