CYTOCIDAL EFFECT OF HIGH-ENERGY SHOCK-WAVE ON TUMOR-CELLS ENHANCED WITH LARGER DOSE AND MULTIPLE EXPOSURES

Cultured LLC-WRC256 (Walker rat carcinoma) cells were exposed to diffe rent doses of high energy shock waves (HESW). The immediate viabilitie s were 98% in the control cells, and 74%, 53% and 18% following 400, 8 00, and 1500 HESW treatment, respectively. Surviving cells in the 400 and 800-treated HESW demonstrated delayed upward growth rate curves, a nd the 1500 HESW-treated a downward curve. Agar clonogenic efficiencie s for surviving cells were 36% (control), 20% (400 HESW), 15% (800 HES W) and 3% (1500 HESW). LLC-WRC256 tumours in Wistar rats were treated once every other day with 1500 HESW on a total of three occasions. Tum ours treated with HESW grew more slowly (4.9 cm3) than those in the co ntrol (13.5 cm3). HESW fragmented cells and destroyed cell membranes a nd intracellular organelles. A histological examination of tumours tre ated with HESW demonstrated local haemorrhage with necrosis in the HES W focus area. Damage to the surrounding skin and soft tissue was sligh t and transient. These findings suggest that the growth of tumour cell s can be suppressed in vitro and in vivo by treatment with HESW.