Evaluation of intracavitary ultrasound arrays for hyperthermia

The feasibility of intracavitary ultrasound hyperthermia was verified experimentally by heating in vitro (alcohol fixed) and in vivo (relocated next to the rectal wall) dog kidneys. Both in vitro and in vivo results showed that, even for a highly perfused organ, the nonfocused arrays effectively deliver energy up to 2-3 cm deep with control over the energy deposition along the length of the array. The circulating water temperature can be used to push the depth of the maximum temperature over 1 cm from the rectal wall, even in a perfused kidney. As expected, perfusion tends to keep this maximum closer to the surface and decreases the overall rise in temperature in the perfused regions. Initial results indicate that intracavitary phased arrays are feasible