Total skin electron beam treatment for canine cutaneous lymphoma

Abstract

Introduction: Generalized cutaneous T‐cell lymphoma (CTCL) in canines has many similarities to CTCL in humans. In humans, early stage mycosis fungoides (MF) patients that do not have lymph node or any systemic involvement can do very well with total skin electron beam irradiation (TSE). In fact, if these early stage patients were treated with 30–35 Gy, the median overall survival was not reached at 15 years. Only one dog with CTCL has been treated with total skin irradiation using orthovoltage irradiation. The patient died the night of the 2nd fraction of RT. Now that more veterinary RT facilities have linear accelerators with electron beam capabilities, it is possible canines with CTCL can be treated with TSE. This paper describes an adaptation of the Modern TSE technique used in human MF patients and its application in canine patients with MF/CTCL.Methods: The modified Modern TSE technique and its application for canine MF/CTCL patients involves 20 treatments given M‐F over 4 weeks. The entire skin surface is treated from multiple directions.Results: Four canine patients with CTCL have been treated with this TSE technique. All patients responded to the treatment initially with the first patient having tumor control for >20 months. One patient has failed the therapy at this date.Conclusions: The TSE technique adapted for use in canines with CTCL was well tolerated with no significant toxicity noted. Development of a collaborative study with other veterinary RT centers having electron beam capabilities is being evaluated through VRTOG.