PREDICTORS OF TREATMENT RESPONSE OF VASOPROLIFERATIVE RETINAL TUMORS TO RUTHENIUM-106 BRACHYTHERAPY.

Purpose: To identify predictors of treatment response by evaluating long-term outcomes of vasoproliferative retinal tumors after ruthenium-106 brachytherapy. Methods: In a retrospective case series, 39 eyes of 38 patients with vasoproliferative retinal tumors received ruthenium-106 brachytherapy between 2001 and 2013. Baseline clinical and morphologic parameters were analyzed regarding posttreatment tumor activity status. Results: Within a median follow-up period of 2.9 +/- 2.9 years, overall, a tumor inactivation was achieved in 72% of cases and visual acuity remained stable in 69%. The mean apex dose was 90 +/- 23 Gy (range, 51-140 Gy). Mean tumor thickness decreased significantly, from 2.9 +/- 0.9 mm to 1.5 +/- 1.0 mm (P 7.5 mm was associated with an 8-fold risk of persistent or recurrent activity, whereas basal area >40 mm2 demonstrated a 6-fold risk (P = 0.009 and 0.021, respectively; Fisher's exact-test). In contrast, tumor thickness was not found to be of prognostic relevance. Conclusion: Ruthenium-106 brachytherapy is an effective and safe therapeutic option for vasoproliferative retinal tumors. Additionally, tumor diameter and area are efficient predictors of persistence or recurrence of tumor activity.