clinical and histopathological effects of prednisone on acute radiation-induced dermatitis in dogs: a placebo-controlled, randomized, double-blind, prospective clinical trial

• Published in: Veterinary dermatology Vol. 18; no. 4; pp. 217 - 226
• Main Authors: Flynn, Alison K, Lurie, David M, Ward, Jennifer, Lewis, Diane T, Marsella, Rosanna
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.08.2007; Blackwell Publishing Ltd
• Subjects: acute course; acute radiation-induced dermatitis; Administration, Oral; adverse effects; Animals; dermatitis; disease severity; dog diseases; Dog Diseases - drug therapy; Dog Diseases - pathology; Dogs; Double-Blind Method; drug evaluation; excision; Female; glucocorticoids; Glucocorticoids - administration & dosage; Glucocorticoids - therapeutic use; histopathology; Male; neoplasms; oral administration; prednisone; Prednisone - administration & dosage; Prednisone - therapeutic use; Prospective Studies; Radiation Dosage; Radiodermatitis - drug therapy; Radiodermatitis - veterinary; radiotherapy; randomized clinical trials; Severity of Illness Index; signs and symptoms (animals and humans); skin lesions; tissue degeneration; Treatment Outcome
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/j.1365-3164.2007.00596.x

This study evaluated and compared the clinical and histopathological effects of prednisone on acute radiation-induced dermatitis (ARID) in dogs treated with 48 Gray of fractionated irradiation targeted to the skin surface. The study was designed as a double-blind, randomized, placebo-controlled prospective clinical trial. Twenty-two otherwise healthy companion dogs completed the clinical study. Three dogs were excluded from complete histopathological analysis because the owner declined one (one dog) or both (two dogs) biopsies. The study duration for each dog was 36 days from the start of radiation therapy (RT) to the first re-examination post RT. Dogs were treated with either oral prednisone at 0.5 mg kg⁻¹ or sugar pill, daily. All dogs received 48 Gray of fractionated, standardized RT, beginning 2 weeks after tumour excision. Acute Radiation Morbidity Scores, Cutaneous Toxicity Extent and Severity scores, digital images, and impression cytology were carried out on days 1, 8, 15, 22 and 36. Four-millimetre skin specimens from days 15 (RT-11) and 36 (2 weeks after the last RT dose) were scored by a pathologist and a dermatologist, blind to specimen identity. A one-way analysis of variance for longitudinal data was used to compare scores between groups. Spearman's rho correlation coefficient was used to measure strength of association between clinical and histopathology scores (HPS). There was no significant difference in CUTES, AMS or HPS scores between groups. There was a strong correlation between clinical and HPS scores. Prednisone did not decrease ARID severity clinically or histopathologically.