THE EFFECTS OF HYPERTHERMIA ON NORMAL MESENCHYMAL TISSUES - APPLICATION OF A HISTOLOGIC GRADING SYSTEM

  • 1 January 1983
    • journal article
    • research article
    • Vol. 107  (6) , 328-334
Abstract
The alterations produced by radio-frequency-induced hyperthermia of 42.degree.-48.degree. C for 30 min were studied in the subcutaneous adipose tissue and skeletal muscle of swine. Acute lesions (18-24 h) included edema, hemorrhage, necrosis (predominantly of myocytes) and granulocytic exudate in fat or muscle. The most important chronic lesion (28-31 days) was fibrosis replacing either tissue. There was a histiolymphocytic exudate with foreign-body giant cells around large lipid vacuoles. Muscle necrosis persisted and there was variable myocyte regeneration. Several specimens showed deep necrosis and abscesses. A grading system was developed to quantitate independently acute and chronic damage in each tissue. Acute lesions were usually less severe and extensive than chronic ones, without obvious dose response. Chronic lesions showed clearly a dose response, which began at 43.degree. C and increased with temperature. The latter appear to be reliable indicators of hyperthermic damage in deep soft tissues. [Hyperthermia is becoming an established treatment modality in cancer therapy.].