Hyperthermia and radiation in the management of canine tumours

Fifty‐one dogs bearing a variety of naturally occurring tumours were treated with combined radiation and hyperthermia. The treatment regime consisted of four, weekly fractions of radiation to a total dose of 3600–4000 cGys and one or two treatments with local microwave hyperthermia, heating the tumour to 44°C for 30 minutes on each occasion. Twenty‐six (51 per cent) of the tumours showed a complete response to this treatment and a further eighteen (35 per cent) tumours underwent significant regression giving a total response rate of 86 per cent. Sixteen tumours later recurred at intervals of 11–50 weeks post treatment. The majority of tumours were in the oral cavity (35 cases) and in this group the survival rate compares favourably with figures for surgical treatment and radiotherapy alone. These findings support published results from other centres, indicating that hyperthermia combined with radiotherapy is a potentially useful technique for the management of certain canine malignant tumours.