Effect of cumulative courses of intraarterial cis‐diamminedichloroplatin‐ii on the primary tumor in osteosarcoma

Preoperative chemotherapy with intraarterial cis‐diamminedichloroplatin‐II (CDP) and mannitol diuresis was administered to the primary tumor in 42 patients with osteosarcoma. The dose was 150 mg/m² and more than 90% of the infusions were administered during a 2‐week period. On occasion this period was extended to 3 weeks because of temporary renal insufficiency or logistical circumstances. Definitive surgical specimens were prepared by means of an arteriogram‐directed plane of dissection with mapping and random sections. Histologically, tumor destruction was evaluated in terms of necrosis, inflammatory response, and fibrovascular regeneration. Quantification of the percent of tumor necrosis was as follows: less than 40% (consistent with spontaneous necrosis and/or no chemotherapy effect); 40% to 60% (possible chemotherapy effect); 60% to 90% (chemotherapy effect—partial response); and 90% to 100% (complete response). Therapeutic efficacy also was correlated with the number of CDP courses (one to three, four to five, and six to seven) and tumor subtype. Significant therapeutic effect (>60% destruction) was observed with four or more CDP courses (one of nine tumors [one to three courses] versus 26 of 33 tumors [four to seven courses] [P = 0.01]). More than 60% of the tumor destruction was observed in the following subtypes: osteoblastic (22 of 28), fibroblastic (three of six), and telangiectatic (two of five). These data demonstrate that four or more courses of intraarterial CDP are required to achieve optimum effects and that osteoblastic osteosarcoma is highly responsive.