Long-term outcome and adverse events following calcium electroporation in 4 dogs with solid malignant tumors.

Abstract

OBJECTIVE: To evaluate the clinical outcome of calcium electroporation in treating canine superficial solid tumors using 1 or 2 treatment sessions and to assess the associated adverse events and effects on quality of life. ANIMALS: 4 client-owned dogs were treated between February 2021 and May 2022. CLINICAL PRESENTATION: This prospective, randomized case series included an oral malignant melanoma, 2 digital melanomas, and a subcutaneous mast cell tumor. Tumors were treated once or twice and monitored for ≥ 180 days (median follow-up, 705 days; range, 180 to 870 days). Tumor response, tumor volume, adverse events, pain scores, and quality of life were recorded. RESULTS: 2 dogs received a single treatment, and 2 dogs received 2 treatments. At day 180, the overall response rate was 75% (1 complete response, 2 partial responses, and 1 progressive disease). Three dogs had no clinical evidence of progression at the time of writing (570 to 870 days posttreatment). Among responders, tumor volume reduction at day 180 ranged from 85% to 100%. No serious adverse events occurred. Transient muscle contractions during pulse delivery and mild swelling with erythema were noted in all dogs for 1 to 3 days. One dog developed a self-limiting grade 1 ulcer that had resolved by day 14. Pain scores remained low, and owners consistently reported good quality of life. CLINICAL RELEVANCE: Calcium electroporation has the potential of being a chemotherapy- and surgery-free local ablative treatment option. Although limited by small case numbers, the findings in this study support further evaluation of calcium electroporation for the treatment of malignant tumors in dogs.