Visual complications of proton beam therapy for clival chordoma.

Purpose: Combining maximal surgical resection with high-dose proton radiation therapy is reported to be currently the best management of patients with clival chordoma.

Method: Since 1991, four consecutive patients from our institution with this tumour have been referred for postoperative proton beam radiotherapy.

Result: We have experienced an unusually high complication rate (50%) of delayed radiation optic neuropathy. This has resulted in profound, bilateral visual loss at 1 and 2 years postproton beam treatment.

Conclusion: It has served as a reminder that proton beam therapy is not an innocuous treatment option and this devastating complication should be taken into account when discussing the management of clivus chordoma. We postulate whether the optic apparatus is particularly sensitive to proton vs photon damage.