Long-term outcome in orbital meningiomas: progression-free survival after targeted resection combined with early or postponed postoperative radiotherapy.

Objective In meningiomas involving the orbit and optic canal, surgery is the mainstay of therapy. However, radical resection is often limited to avoid functional damage, so multidisciplinary treatment concepts are implemented. Data on the timing and value of early postoperative radiotherapy (PORT) are scarce. This retrospective study analyzes outcomes in patients who underwent targeted resection alone or in combination with early PORT. Methods Patients undergoing resection of orbit-associated WHO grade I meningiomas from January 1999 to December 2013 who presented to the authors' department at least twice for follow-up were included. Clinical and radiological findings were analyzed retrospectively. Patients were stratified into two cohorts: follow-up with MRI scans at regular intervals, i.e., the watch and wait (WW 87.7% of patients received Simpson grade II-III targeted partial resection. Twenty-three patients received PORT, and 99 patients were regularly observed with MRI scans (W&W group). Tumor recurrence/progression occurred significantly later (76.3 vs 40.7 months) and less frequently in the PORT group (13%) than in the W&W group (46.5%). Cases of recurrence were diagnosed an average of 39 months after initial surgery in both groups. PORT patients demonstrated significantly less visual impairment at last follow-up. Conclusions These results indicate that receiving PORT early after targeted partial resection might help to postpone tumor recurrence and the need for additional treatment, while preserving or even improving visual outcome.