Intraoperative sonographically assisted radioactive iodine 125 plaque brachytherapy for choroidal melanoma: Visual acuity outcome

Objectives-The purpose of this study was to present a retrospective series of cases from a single Canadian academic center assessing visual acuity outcomes after intraoperative sonographically assisted iodine 125 (¹²⁵I) plaque brachytherapy treatment. Methods-The cases of 28 patients (16 male and 12 female; mean age ± SD diagnosis, 62.3 ± 15 years) with choroidal melanoma treated with ¹²⁵I plaque brachytherapy using intraoperative sonography between 1997 and 2002 were reviewed. Results-The mean longitudinal, transverse, and depth dimensions were 11.4, 10.6, and 4.7, respectively. The median follow-up was 48 months (range, 3-102 months) for our cohort of patients. The prescribed dose was 85 Gy to a height of 5 mm (for an apex height ≤5 mm) or to the tumor apex (for an apex height >5 mm). Five years after ¹²⁵I plaque brachytherapy, all tumors had regressed in their longitudinal, transverse, and depth dimensions. The prebrachytherapy tumor depth (P = .023) and sclera dose (P =.036) were found to significantly affect visual acuity after plaque brachytherapy at 24 months. One recurrence was recorded 6 years after plaque brachytherapy. Conclusions-This study supports ¹²⁵I plaque brachytherapy as an efficacious treatment for patients with choroidal melanoma, and intraoperative sonography may help with optimizing tumor control. In addition, to our knowledge, this study is the first to report the sclera dose as a significant predictor of visual acuity.