[The subrenal capsule assay modified with three-dimensional measurement (volume method) and its higher predictivity].

Subrenal Capsule Assay (SRCA) developed by Bogden et al. is a new in vivo sensitivity test for anticancer agents. However, the presence of host reaction on about day 6 is largest problem for this method, and now many researchers are scrutinizing or introducing several modifications for this assay chiefly by immunosuppressing procedures. As one of the means to measure the actual change of the tumor volume and minimize the misreading of host reactions, we introduced three dimensional measurements of the grafts (volume method) instead of original mean diameter measurement. Using this method, prospective quantitative study was made. The results of 16 assays with 15 cases of miscellaneous malignancies showed 94% evaluability and in 22 treatments predictive accuracy was 77%. Assay/clinical correlation coefficient was 0.38 and coincidence of ranking order of the effectiveness was 6/6, with good contrast to those of 78%, 56%, 0.00 and 1/3, by original method respectively. Clinical responses more than PR were obtained in 9 of 15 cases. Two cases are still in CR for two years by assay directed single agent treatments. Many other minor modifications were also adopted and evaluated by quantitative observation of assay/clinical correlations. SRCA with our modifications seemed to have utilities than original.