External beam radiotherapy (20 Gy, 2 Gy fractions) fails to control the growth of choroidal neovascularization in age-related macular degeneration: a review of 111 cases

BACKGROUND: Control of the natural course of choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) is difficult, and laser photocoagulation is recommended in only a subset of patients. Alternative modalities of treatment are under investigation. METHODS: We have used external beam radiotherapy (20 gray radiation units Gy], 2 Gy fractions) to treat CNV in ARMD. A total of 111 patients have been followed for 12-30 months after radiotherapy. This study evaluates the effect of radiotherapy on the size of CNV, which was digitally measured on serial fluorescein angiograms. RESULTS: Analysis of results in the classic (or mixed classic and occult) CNV group was conclusive for fast growth of CNV and continuous increase of size during follow up. In the occult CNV group, a slowly progressive growth of CNV was demonstrated. In patients with vascularized pigment epithelium detachments, "hot spots" persisted; in a few patients, flattening of the macula was observed. Nearly all treated patients experienced further loss of vision. CNV growth in the radiotherapy treated eye was usually similar to growth in the untreated fellow eye, and in some, even worse. CONCLUSION: External beam radiotherapy (20 Gy, 2 Gy fractions) failed to control growth of CNV and was ineffective in stabilizing vision.