WOUND REPAIR AFTER FRACTIONATED EXTERNAL-BEAM RADIATION-THERAPY AND CONCOMITANT HYPERTHERMIA IN AN EXPERIMENTAL RAT MODEL

Background. Fractionated radiation therapy (RT) with adjuvant hyperthe rmia (HT) is being used in the treatment of cancer with noted clinical success. However, little information regarding wound repair in tissue s receiving this combination therapy is available for comparison of su rgical risk. Consequently, this study was undertaken to assess the eff ects of this combined therapy on wound healing by quantitatively evalu ating wound repair using tensile strength measurements. Methods. Four treatment cohorts were designated: sham control, RT alone (600 cGy/d f or 4 days), HT alone (water bath at 41.8-degrees-C, subcutaneous tempe rature of 41.0 +/- 0.5-degrees-C for 60 minutes on days 1 and 4), and combined RT and HT. At 1 week after treatment, surgical incisions of t he dorsal flank were made. Tensile strength measurements of wounds wer e obtained at 14 and 21 days after incision. Results. No significant d ifferences were observed in the combined treatment arm (RT and HT) com pared with the reduced wound breaking strength of RT alone. Statistica lly significant differences in tensile strength were seen when the con trol group or HT alone was compared with RT and HT or RT alone. Conclu sions. Concomitant exposure to fractionated RT and specific HT conditi ons demonstrated no disproportionate alteration in wound tensile stren gth compared with radiation exposure alone in this animal model.