title: Millimeter waves as a source of selective heating of skin.
abstract: This study demonstrates that 20-100 GHz range can be used for spatially-accurate focusing of heating inside the skin achieved by varying frequency and exposure beam size, as well as by enforcing air convection. The latter is also used to reduce overheating of skin surface. Heating at different skin depths depending on these parameters is investigated in detail using the hybrid bio-heat equation. In particular, it is shown that decreasing frequency and/or increasing exposure beam size at forced airflow result in elevation of heating of deeper layers of tissue and decrease of skin surface temperature. Changes of water content within 15%, which exceed those due to aging and presence of tumors, only slightly affect heating. Exposure intensity necessary to reach a target temperature significantly increases in different areas of body with elevated blood flow. Dependence on exposure intensity and hyperthermia treatment duration is also investigated and discussed. Results of this study suggest that the lower part of the millimeter-wave range is an attractive alternative for non-invasive thermal treatment of skin cancer with a high spatial resolution.
authors.affiliation: Institute of Electronics and Telecommunications of Rennes (IETR), UMR CNRS 6164, University of Rennes 1, Rennes, France.
authors.forename: Maxim
authors.initials: M
authors.lastname: Zhadobov
authors.affiliation: Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Stanislav I
authors.initials: SI
authors.lastname: Alekseev
authors.affiliation: Institute for Research on Environmental and Occupational Health (IRSET), University of Rennes 1, Rennes, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Le Dréan
authors.affiliation: Institute of Electronics and Telecommunications of Rennes (IETR), UMR CNRS 6164, University of Rennes 1, Rennes, France.
authors.forename: Ronan
authors.initials: R
authors.lastname: Sauleau
authors.affiliation: Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Evgeny E
authors.initials: EE
authors.lastname: Fesenko
mesh_terms: D000388:Air; D001775:Blood Circulation / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006358:Hot Temperature; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D007700:Kinetics; D008545:Melanoma / Q000098:blood supply / Q000378:metabolism / Q000628:therapy; D008872:Microwaves / Q000627:therapeutic use*; D008954:Models, Biological; D012867:Skin / Q000098:blood supply / Q000378:metabolism / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000098:blood supply / Q000378:metabolism / Q000628:therapy; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water
keywords: 20 -100 GHz range; dosimetry; hybrid bio-heat equation; hyperthermia