Infrared Thermography and Hyperthermia
The treatment of cancer by hyperthermia requires careful control of the temperature within the tumor as well as in overlying healthy tissues. For hyperthermia to be effective clinically it is necessary to maintain the tumor at a higher temperature than normal tissues.1 Tumor cell kill and normal tissue tolerance are dependent critically upon temperature magnitude and duration of heating, as summarized by Overgaard.2 The length of a treatment will therefore depend upon the temperature attained within the tumor and also the temperature differential between healthy and abnormal cells. Clinical studies indicate the effectiveness of achieving tumor temperatures in the range 42–43°C for periods of 45 minutes when incorporated into a treatment schedule involving the use of radiotherapy, chemotherapy or radiation sensitizers.3,4 The effective use of hyperthermia alone however, may require higher tumor temperatures owing to the influence of vascular cooling as discussed by Lagendijk.5 Ideally the hyperthermia technique should generate adequate heating throughout the tumor without causing similar temperature increases in surrounding normal tissues, and to achieve this end it is necessary to investigate the optimization of various heating modalities with respect to each particular clinical site and tumor type to be treated. Popular heating techniques currently under investigation utilize electromagnetic fields, microwaves and ultrasound to transfer energy to the tissues. The relative merits of these methods have been described by Hand and ter Haar.6 This paper is concerned primarily with the use of RF (27 MHz) electromagnetic field techniques for the induction of localized hyperthermia, and the ways in which IR thermography may be used as an aid to temperature measurement. In principle, the thermographic methods described may be applied when other heating modalities are employed.
KeywordsInfrared Thermography Microwave Radiometer Heating Pattern Localize Hyperthermia Hyperthermia Therapy
Unable to display preview. Download preview PDF.
- 2.J. Overgaard, The effect of local hyperthermia alone, and in combination with radiation, on solid tumors, in: “Cancer Therapy by Hyperthermia and Radiation,” C. Stoffer ed., Urban and Schwarzenberg, Baltimore, Munich (1978).Google Scholar
- 3.G. Arcangeli, A. Cividalli, G. Lovisolo, F. Mauro, G. Creton, C. Nervi, G. Pavin, Effectiveness of local hyperthermia in association with radiotherapy or chemotherapy: comparison of multimodality treatments on multiple neck node metastases, in: “Proceedings 1st Meeting of European Group of Hyperthermia in Radiation Oncology,” Cambridge, Masson (1979).Google Scholar
- 6.J. W. Hand, G. R. ter Haar, Heating techniques in hyperthermia, Brit. J. Radiol. 54: 443 (1981).Google Scholar
- 9.D. W. Armitage, Three dimensional simulation of power absorbed by the human body from radiofrequency applicators (abstract). 2nd Meeting of European Group of Hyperthermia in Radiation Oncology, Rome (1980).Google Scholar
- 11.P. Carnochan, M. Jancar, C. H. Jones, The assessment of RF inductive applicators suitable for clinical hyperthermia, Brit. J. Cancer 45 (suppl. V): 25 (1982).Google Scholar
- 12.K. Lloyd-Williams, Thermography in the prognosis of cancer, in: “Medical Thermography,” Proceedings of a Boerhaave Course or Postgraduate Medical Education. Leiden 1968, Bibl. Radiol. 5:62 Karger, Basel/New York (1969).Google Scholar
- 13.P. Bourjat, M. Gautherie, E. Grosshaus, Diagnosis, follow-up and prognosis of malignant melanomas by thermography,in: “Thermography,” Proceedings 1st European Congress Amsterdam 1974. Bibl. Radiol. 6:115 Karger, Basel (1975).Google Scholar
- 14.F. Amalric, D. Giraud, C. Altschuler, R. Amalric, J. M. Spitalier, Infrared thermographie follow-up after breast cancer curative radiotherapy, Acta Thermographica 4: 54 (1979).Google Scholar