Lack of radiation optic neuropathy in 72 patients treated for pituitary adenoma

The incidence of radiation optic neuropathy (RON) after external photon beam radiation therapy for nonfunctioning pituitary adenoma (NFA) is not well-studied. Retrospective review of ophthalmological and imaging data in 72 patients with NFA treated between 1985 and 1998 with external beam radiation therapy after surgery. Clinical follow-up after radiation therapy had to be at least 18 months. RON was defined as a sudden and profound irreversible visual loss affecting the optic nerve or chiasm. A review of previously published cases of RON was then performed. In our cohort, no patient had RON. A total of 11 adequately documented series reports of RON were found in the medical literature on radiation-treated NFAs. The incidence of RON in NFA from these series is 0.53% (95% CI, 0.26%-0.96%). An additional 14 single RON cases have been reported, bringing the total of adequately documented RON cases to 25. RON is a rare complication after external beam radiation therapy for NFA.