Introduction

High-temperature hyperthermia (HTH) is an established treatment option for cancer, particularly for superficial types of cancer.

Objective

The aim of the present study was to reveal the exact correlation between HTH at temperatures of 50–70°C and the effects of HTH therapy for the treatment of spontaneous tumors in canines.

Methods

In this study, a tissue ablation device for veterinary medicine (AMTC 200; Alexon Inc., Ehime, Japan) was used. In the experimental study, HTH was performed for 10 min at 70, 60 or 50°C. On days 0, 3, 6, 9 and 12, the volumes of the tumor tissues were calculated. In the clinical study (3 cases), HTH treatment was performed in all three cases for 10 min at 45–65°C with or without the inhalation of isoflurane.

Results

In the 60°C (T-60) and 70°C (T-70) HTH groups, tumor growth rates were significantly suppressed compared with those in the non-treatment (NT) group. In the 50°C (T-50) HTH group, tumor growth rates were not suppressed compared with those in the NT group. In case 1, the tumor disappeared four weeks following HTH treatment. In case 2, the tumor volume had decreased by day 21, and in case 3, HTH was performed three times and the tumor disappeared following the third procedure.

Conclusion

High-temperature hyperthermia is considered to be a simple procedure with no severe side effects. Consequently, this treatment modality is hypothesized to become a useful alternative therapy for superficial tumors in companion animals.