This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Oleson, J. R. Search for Related Content PubMed PubMed Citation Articles by Oleson, J. R.

Regional Power Deposition for Hyperthermia: Theoretical Approaches and Considerations¹

Division of Radiation Oncology, University of Arizona Health Sciences Center, Tucson, Arizona 85724

Physical analysis of electromagnetic and ultrasonic fields is useful to define systems capable of depositing power in "deep" tumors extending more than a few cm from the skin surface. Several recent analyses of electromagnetic field configurations for treating such tumors are reviewed here. Most electromagnetic systems result in exposure of substantial normal tissue volumes or regions to unfocused power absorption, and safely achieving intratumoral temperature elevation to 42° relies in part upon higher blood flow rates existing in normal tissue than in tumor. Optimizing therapeutic approaches to deep tumors with devices producing regional power deposition may thus require improved knowledge and control of regional blood flow distributions, along with further development of energy sources appropriate for specific deep sites. Multiple electric dipole sources with separate phase and amplitude control appear to be the most general noninvasive electromagnetic solution at present for deep heating. In specific locations, focused ultrasound is also theoretically capable of producing advantageous power deposition at depth.

¹ Presented at the Workshop Conference on Hyperthermia in Cancer Treatment, March 19 to 21, 1984, Tucson, AZ. This work was supported by Grant 0217343 and Contract NO1-CM-17522 from the National Cancer Institute, NIH.

² Present address: Division of Radiation Oncology, Duke University Medical Center, Box 3808, Durham, NC 27710.