Treatment of intraorbital lesions using the Accuray CyberKnife system

The goal of this study was to better understand the safety and efficacy of CyberKnife image-guided radiosurgery for lesions immediately adjacent to the optic nerves.

This retrospective, non-comparative, interventional case series included 16 patients (6 women and 10 men) with lesions located wholly within the orbit. Thirteen cases involved tumors (31% benign and 69% malignant), two cases presented with chronic orbital inflammation and one patient had intraorbital tissue growth secondary to Graves disease. Staged radiosurgical ablation was performed using CyberKnife image-guided technology. The main outcome measures analyzed were change in tumor/neoplasm size, pain, visual field preservation and visual acuity, which were followed for up to 15 months.

Twelve patients had a postoperative MRI, which revealed either a decrease or stabilization of tumor size. In the five lymphoma cases there was complete disappearance of the tumor. Pretreatment pain resolved in all 10 patients who reported it before the procedure; improvement in pain typically occurred within 1-2 weeks of radiosurgery. All 16 patients had a visual evaluation performed after the procedure: of these, 15 had no change in their visual field and one reported improvement. Visual acuity was preserved in 13 patients and improved in two, while one patient developed diplopia.

Staged CyberKnife radiosurgery is an effective option for the treatment of intraorbital lesions that controls tumor size, relieves pain, and preserves vision. The long-term safety of this treatment remains to be confirmed.