Interaction of ultrasound with neoplastic tissue: IV. alteration of biologic activity in cells derived from rat Wilms' tumor sonicated in vivo.

Paired Wistar-Furth male rats were implanted subcutaneously with the Furth-Columbia rat Wilms' tumor. Seven days after implantation the tumors were either subjected to therapeutic ultrasound irradiation or were left as untreated controls. On the ninth day after implantation the animals were sacrificed, and suspensions of cells were made from the excised tumors by trypsinization. The cells were counted using trypan blue dye as an indicator of viability. New rats were then implanted with cells either from sonicated tumors or cells from controls. In half the recipient animals the suspensions were matched by total cell count. In the other half of the rats cell counts were matches for viability by the dye exclusion test. Tumors developed in a total of 8 of 11 rats receiving control cells and they died. A palpable tumor did not develop in any rat receiving cells fromsonicated tumors during the ninety-day study period. Surviving rats were challenged with Wilms' tumor by trocar implant. Tumor developed in all recipients, and they died.