Radiation therapy in the treatment of canine and feline thymomas: a retrospective study (1985-1999)

Abstract

A retrospective study was performed of 17 dogs and seven cats with various stages of thymoma treated with radiation alone or as an adjunctive therapy. Analysis revealed an overall response rate of 75% (15/20 evaluable cases). Partial (i.e., >50% reduction in tumor size) and complete (i.e., no detectable tumor) responses were included. Complete responses were rare (4/20). Three of five animals with stable disease (i.e., <50% change in tumor size) had improvements in clinical signs, despite lack of measurable response. A median survival time of 248 days (range, 93 to 1,657+ days) was achieved in dogs, and a median survival time of 720 days (range, 485 to 1,825+ days) was achieved in cats. Radiation therapy appears to be useful in the management of invasive thymomas in dogs and cats.

Perioperative Mortality and Long‐Term Survival in 80 Dogs and 32 Cats Undergoing Excision of Thymic Epithelial Tumors

“…The largest report described a multi-institutional study of 17 dogs and 7 cats treated with radiation alone or as adjunctive therapy and reported estimated median survival times of 248 days in dogs and 720 days in cats, with partial or complete responses in 75% of animals. 34 Consistent with these results, 5 of 8 dogs in the recent multi-institutional case series had a partial response to radiation therapy. 11 Reports on the efficacy of chemotherapy for thymoma are available for a small numbers of cases.…”

Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001–2012)

“…Reports of outcomes are limited 34, 41. One study suggests a median survival time of 720 days in cats undergoing radiation therapy41 versus 3.71 years in cats undergoing surgery for thymoma 22.…”

Paraneoplastic exfoliative erythroderma in a cat with thymoma

“…However, of as many as 100 feline thymomas retrieved by the authors in a literature review, only 16 had exfoliative dermatitis (Loveday 1959, Dubielzig andJOURNAL OF THE HELLENIC VETERINARY MEDICAL SOCIETY 2011,62(3) ΠΕΡΙΟΔΙΚΟ ΤΗΣ ΕΛΛΗΝΙΚΗΣ ΚΤΗΝΙΑΤΡΙΚΗΣ ΕΤΑΙΡΕΙΑΣ 2011,62(3) DeLaney 1980, Willard et al 1980, Carpenter and Holzworth 1982, Bonnard and Dralez 1992, Gores et al 1994, Scott et al 1995, Forster-van Hijfte et al 1997, Day 1997, Godfrey 1999, Riviere and Olivry 1999, Smith et al 2001, Smits and Reid 2003, Rottenberg et al 2004, Lara-Garcia et al 2008, Fidel et al 2008, Spadavecchia and Jaggy 2008, Zitz et al 2008, Singh et al 2010. Apart from exfoliative dermatitis, myasthe nia gravis is a well-known paraneoplastic condition in cats with thymoma, appearing alone or in combination with the former dermatitis (Scott-Moncrieff et al 1990, Singh et al 2010); polymyositis and granulocytopenia may, also, develop but far less commonly (Moore andOgilvie 2001, Fidel et al 2008).…”