3D-conformal radiation therapy induced eyelid and corneal acute complications in dogs with head tumors

Abstract

This study evaluated the incidence of acute eyelid and/or corneal complications (AC) in 172 eyes of 86 dogs with head tumors treated by 3D-conformal radiation therapy (3D-CRT). AC occurred in 24 eyes (13.9%), presenting as blepharoconjunctivitis, non-ulcerative keratitis, ulcerative keratitis, or corneal perforation. Median shortest distance from the ocular center to the tumor margin (DOCT), ocular cumulative exposure dose (OCED), and ocular radiation exposure rate (ORER) in AC cases (12.8 mm, 24.5 Gy, 72.5%) were significantly higher or shorter than in non-AC cases (26.4 mm, 12.6 Gy, 35.0%) (P < 0.01). All AC occurred during or within 21 days after 3D-CRT. Receiver operating characteristic curve analysis identified cut-off values for AC prediction: DOCT 17.6 mm, OCED 17.5 Gy, and ORER 55.0%. These parameters may aid in AC risk assessment in canine head tumor radiotherapy.