Whole-body hyperthermia combined with hyperfractionated irradiation of the thorax in dog: acute physiological response.
Whole-body hyperthermia has potential as an adjuvant treatment with chemotherapy and radiation therapy for diseases such as lung cancer which require both local and systemic control. The acute toxicity of whole-body hyperthermia combined with whole-thorax irradiation was studied in dogs. Twenty-eight dogs received three 2-h whole-body hyperthermia (WBH) treatments at 42.0 degrees C deep rectal temperature. Twenty-four of these dogs were also randomized to receive radiation doses of 18, 22.5, 27, 31.5, 40.5 or 45 Gy. Irradiation was given in 1.5 Gy fractions over 6 weeks. Three WBH treatments were given to 28 dogs with all dogs surviving treatment. WBH was given on days 1, 22 and 40 of the 6-week interval. Thirty-one dogs received radiation doses of 18-49.5 Gy without WBH. Deep rectal temperature was maintained at 41.9 +/- 0.3 degrees C over 2 h with an average of 20 min outside the chamber for irradiation. Two dogs required intervention with emergency medications during WBH treatment. One of the two dogs developed permanent neurological injury. Continuous physiological monitoring was necessary for successful WBH. WBH plus thoracic irradiation was well tolerated. All dogs survived all treatments. A significant but transient increase in peripheral blood leucocytes and a decrease in platelet counts occurred after each WBH treatment. The addition of thoracic irradiation up to 45 Gy in 1.5 Gy fractions did not appear to alter the acute toxicity of WBH with the exception of an increase in the protein content of lung lavage fluids. In conclusion, multiple WBH treatments of 2 h at a target temperature of 42 degrees C in addition to thoracic irradiation up to 45 Gy in 1.5 Gy fractions was administered with only mild acute toxicities occurring. Core temperature could be maintained for up to 20 min outside of the WBH chamber which allowed irradiation to be given concurrently with hyperthermia at a core temperature of 42 degrees C +/- 0.1 degree C.
Department of Radiological Health Sciences, Colorado State University, Fort Collins 80523.
S
S
McChesney Gillette
C A
CA
Dawson
R J
RJ
Scott
D A
DA
Rickaby
B E
BE
Powers
M R
MR
Johnston
C
C
Chen
E L
EL
Gillette
D000818:Animals; D001772:Blood Cell Count; D001794:Blood Pressure; D001992:Bronchoalveolar Lavage Fluid / Q000473:pathology; D004285:Dogs; D006979:Hyperthermia, Induced / Q000009:adverse effects*; D008168:Lung / Q000528:radiation effects; D055370:Lung Injury; D011833:Radiation Injuries, Experimental / Q000209:etiology / Q000503:physiopathology; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D013821:Thermometers; D013898:Thoracic Injuries / Q000209:etiology; D013909:Thorax / Q000528:radiation effects