Advanced ultrasonic techniques for local tumor hyperthermia.

Scanned, intensity-modulated, focused ultrasound (SIMFU) presently is the modality of choice for localized, controlled heating of deep as well as superficial tumors noninvasively. With the present SIMFU system, it was possible to heat 88 per cent of deep tumors up to 12 cm in depth and 15 cm in diameter, to 43 degrees C in 3 to 4 minutes. The infiltrative tumor margins could be heated to the desired therapeutic temperature. The temperature outside the treatment field fell off sharply. Excellent objective responses were obtained without local or systemic toxicity. Multiinstitutional clinical trials of local hyperthermia by this promising technique are clearly warranted.