[High-dose ifosfamide in the treatment of patients with soft tissue sarcoma]

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.