Abstract
Purpose: :
Choroidal hemangiomas are the most common benign vascular tumors of the uveal tract. Treatment is geared towards decreasing subretinal fluid, maintaining vision, and preserving the eye. Proton beam irradiation (PBI) using localization with tantalum rings has been shown to be effective in treating choroidal hemangiomas. We aim to evaluate the effect of PBI using a nonsurgical light field technique in the treatment of choroidal hemangiomas.
Methods: :
A retrospective chart review was performed of 19 patients that underwent proton beam irradiation using a light field technique for treatment of choroidal hemangioma from 1989 to 2001. We treated 19 eyes of 19 patients with either diffuse choroidal hemangiomas associated with Sturge Weber or circumscribed choroidal hemangiomas with a tumor height > 3mm. The total applied dose was between 15 cobalt gray equivalents (CGE) to 30 CGE divided into 4 courses. We evaluated visual acuity, tumor location, incidence of radiation retinopathy following PBI, regression of subretinal fluid, and regression of tumor height.
Results: :
4 of the 19 patients were lost to followup and were not included in assessment of the results. Visual acuity improved or remained the same in 9 of 15 eyes (60%). Of these 9 eyes, the lesion was located superotemporally in 2 eyes, superonasal in 2 eyes, nasal in one eye, involving the macula in 3 eyes, and in the inferotemporal periphery in one eye. Of the 6 eyes that showed a decrease in visual acuity, the lesion was located superotemporally in 3 eyes, inferotemporally in 1 eye, inferonasal involving the optic nerve in 1 eye, and involving the macula in 1 eye. An initial retinal detachment was present in 8 of 15 eyes (53.3%), 4 of which experienced a decreased final visual acuity. Radiation retinopathy developed in 4 of 15 eyes (26.67%) with an applied dose measuring between 16 CGE to 25 CGE for these 4 eyes. Subretinal fluid resolved completely in 8 of 8 eyes, and tumor height, as measured on B–Scan ultrasonography, decreased in 14 of 15 eyes and remained unchanged in 1 of 15 eyes.
Conclusions: :
Proton beam irradiation using a light field technique is a good treatment option in managing both larger circumscribed choroidal hemangiomas and diffuse choroidal hemangiomas asscociated with Sturge Weber syndrome. A total proton dosage ranging from 15 CGE to 30 CGE applied in 4 courses appears to be sufficient to maintain visual acuity and reduce tumor size. By using the light field technique, the patient is spared from the additional surgery required for suturing of tantalum rings.
Keywords: radiation therapy • tumors • oncology