M. Oka reported on the successful use of focused ultrasound to treat thyroid and breast cancers.
Oka M. Progress in studies of the potential use of medical ultrasonics. Wakayama Medical Report (Japan). 1977;20:1-50.
Oka M. Application of intense focused ultrasound in brainsurgery and other fields. Clinica All-Round (Japan). 1964;13:1514.