Proton Beam Irradiation Using a Light-Field Technique for the Treatment of Choroidal Hemangiomas

Abstract

Background/Aims: To describe the clinical outcomes of patients with circumscribed and diffuse choroidal hemangiomas treated by proton beam irradiation using a nonsurgical light-field technique. Methods: A retrospective chart review was performed on a series of 19 patients (19 eyes) with choroidal hemangiomas treated with proton beam therapy between July 1988 and August 2005. Choroidal hemangiomas were treated with proton beam irradiation using a light-field technique and doses ranging from 15 to 30 cobalt Gray equivalents (CGE; CGE = proton Gy × relative biological effectiveness 1.1) in 4 fractions. Patients with at least 6 months’ follow-up were included in the study. Tumor regression, visual acuity, absorption of subretinal fluid, and treatment-associated complications were evaluated by clinical examination and ultrasonography. Results: Visual acuity improved or remained stable in 14 of 18 eyes (78%). Subretinal fluid was initially present in 16 of 19 eyes (84%), and completely resolved in all 16 eyes. Tumor height, as measured by B-scan ultrasonography, decreased in 18 of 19 eyes and remained stable in 1 of 19, as of the last examination. Complications of radiation developed in 9 of 19 eyes (47%) with the total applied dose ranging from 15 to 30 CGE for these 9 eyes. Conclusions: Proton beam irradiation using a light-field technique without surgical tumor localization is an effective treatment option in managing both circumscribed choroidal hemangiomas and diffuse hemangiomas associated with Sturge-Weber syndrome. A total proton dose as low as 15 CGE applied in 4 fractions appears to be sufficient to reduce tumor size, promote absorption of subretinal fluid, and improve or stabilize vision in most patients.