The effectiveness and safety of proton radiation therapy for indications of the eye : a systematic review

BACKGROUND AND PURPOSE: : Proton radiation has been used for the treatment of
uveal melanoma since 1975, but few studies have been conducted to assess its
efficacy and safety. This paper aims to systematically review the effects and
side effects of proton therapy for any indication of the eye.
MATERIAL AND METHODS: : A range of databases were searched from inception to
2007. All studies that included at least ten patients and that assessed the
efficacy or safety of proton therapy for any indication of the eye were included.
RESULTS: : The search generated 2,385 references, of which 37 met the inclusion
criteria. Five controlled trials, two comparative studies and 30 case series were
found, most often reporting on uveal melanoma, choroidal melanoma and age-related
macular degeneration (AMD). Methodological quality of these studies was poor.
Studies were characterized by large differences in radiation techniques applied
within the studies, and by variation in patient characteristics within and
between studies. Results for uveal melanoma and choroidal melanoma suggest
favorable survival, with, however, significant rates of side effects. Results for
choroidal hemangioma and AMD did not reveal beneficial effects from proton
radiation.
CONCLUSION: : There is limited evidence on the effectiveness and safety of proton
radiation due to the lack of well-designed and well-reported studies. There is a
need to lift evidence on proton therapy to a higher level by performing
dose-finding randomized controlled trials (RCTs), comparative studies of proton
radiation versus standard given alternatives and prospective case studies
enrolling only patients treated with up-to-date techniques, allowing
extrapolation of results to similar patient groups.