Introduction

We developed a novel cancer therapy to create a triple therapy strategy (photodynamic therapy, hyperthermia therapy, and chemotherapy) called photodynamic hyperthermal chemotherapy (PHCT).

Objective

The aim of this study was to evaluate the effects of PHCT for the clinical cases of soft tissue sarcoma (STS).

Methods

Sixteen cases of malignant STS (10 canines and six felines) were treated with PHCT after surgical tumor resection. One ml of the ICG solution was administered per cm² of the wound bed. Irradiation was administered at a distance of 10 cm from the resected area (irradiation area: 113 cm², 40 mW/cm²) for 20 min per 113 cm² (48 J/cm²) immediately after the ICG solution was injected. The temperature at the surface of the resected area was kept under 45°C and monitored with a thermometer.

Results

No severe side effects, including severe skin burns, necrosis or skin suture rupture, were observed in any of the animals. No disease recurrence was observed in 7 out of 10 (70.0%) dogs and 3 out of 6 (50.0%) cats over the follow-up periods ranging from 238 to 1901 days.

Conclusion

PHCT decreases the risk of STS recurrence. PHCT should therefore be considered an adjuvant therapy for treating companion animals with STS in veterinary medicine.