In vivo effects of high energy shock waves on urological tumors: an evaluation of treatment modalities.

We have studied the effect of high energy shock waves (HESW) alone or in combination with cytotoxic drugs on the growth of urological tumors. The effects of HESW on kidney or prostatic tumors depend largely on the tumor line used. In the rapidly growing prostate tumor no antitumor effect was evident in vivo, but in vitro examination of the in vivo shocked cells showed that the clonogenic potential of HESW treated cells was inhibited. In the more slowly growing tumors, like human kidney xenografts, a temporary growth delay is observed in vivo. The effect on tumor growth depends not only on the number of HESW administered but also on the initial tumor volume. The smaller the tumor burden, the better the antitumor effect. Single shock wave administration may cause a growth delay, and repeated administration leads to a prolonged delay in growth. This effect is temporary and several days after stopping the HESW administration the tumor regains its original growth potential (same doubling time). Finally we could show that tumor growth was suppressed in different tumor models for a longer period by a combination of HESW and a single dose of adriamycin. The effect of combined treatment resulted in a persistent longer doubling time.