Abstract
Purpose :
While radiation therapy permits globe salvage for patients with uveal melanoma, most patients experience vision complications and a decline in visual acuity (VA) after treatment. In this study, we aim to better understand patient, tumor and treatment characteristics that correlate with the development of unfavorable vision outcomes in patients treated with plaque brachytherapy.
Methods :
Retrospective chart review was performed for 270 consecutive adults treated with I-125 plaque brachytherapy at Oregon Health and Science University from 2013 through 2018. Patients who previously received alternative therapy and those with multiple primary tumors were excluded. Participants with baseline VA better than or equal to 20/50 and 20/200 were used to evaluate for VA worse than 20/50 and 20/200 at the end of the study, respectively. Multivariate logistic regression models at 3 and 5 years post-treatment were fit using variables that showed association in univariate analysis (p<0.20). All variables were tested for multicollinearity. Parameters in this study included sex, age, presence of cataracts or diabetes, tumor size (basal diameter and height), tumor location, and radiation dose to the tumor apex, fovea and optic disc.
Results :
At baseline, 226 patients presented with VA ≥ 20/50 and 253 with VA ≥ 20/200. Of these patients, 24.78% (56) and 18.18% (46) had VA worse than 20/50 and 20/200 after 3 years, respectively. For those with baseline VA ≥ 20/50, multivariate analysis at year 3 showed larger tumor height (p<0.01, OR=1.8) and greater radiation dose to the fovea (p=0.05, OR=1.01) to be associated with greater odds of vision loss; while only tumor height (p=0.06, OR=2.01) was predictive of vision loss at year 5. Similarly, for patients who presented with VA ≥ 20/200, tumor height (p<0.01, OR=1.69) was significant at year 3 and remained significant through year 5 (p=0.03, OR=1.9).
Conclusions :
At both 3 and 5 years post brachytherapy, tumor height was the most significant predictor of vision loss in our cohort when controlling for various tumor, patient and treatment characteristics. Future analyses will include evaluation of a published nomogram for vision loss (Khan, N, et al, International Journal of Radiation Oncology Biology Physics, 2012) using our dataset to determine its generalizability as a means for predicting vision outcome after plaque brachytherapy.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.