Resection and permanent intracranial brachytherapy using modular, biocompatible cesium-131 implants for recurrent aggressive meningiomas: 5-year results from a prospective phase 2 trial.

OBJECTIVE

Maximal resection of meningiomas is the gold standard of therapy, yet recurrence following surgery alone is fairly common, particularly with more aggressive tumors. The authors explored the efficacy of treatment of recurrent, aggressive meningiomas with resection plus Cs-131 collagen tile brachytherapy (R+CTBT).

METHODS

This was a prospective, nonrandomized, single-center trial that enrolled patients with recurrent aggressive meningiomas between June 2013 and January 2018. All patients underwent maximal safe resection and placement of Cs-131 tiles for CTBT. Local progression, defined as tumor recurrence within 1.5 cm of the operative bed, was determined on follow-up imaging, and hazard ratios were determined to compare the efficacy of R+CTBT with prior treatment at the same site.

RESULTS

Twenty-nine recurrent aggressive meningiomas were treated in 27 patients with a median age of 66 (range 37-82) years. The WHO grade at the time of R+CTBT was grade 1 in 1 (3%) case, grade 2 in 26 (90%), and grade 3 in 2 (7%). The median radiographic follow-up was 34.8 (range 0.0-70.9) months. Local control at 48 and 60 months was 73% and 48%, respectively, following R+CTBT compared with 21% and 17% with prior treatment (HR 0.145, p < 0.001). Surgery-related complications occurred in 4 cases (14%), including 1 case (3%) with early postoperative infection and 3 (10%) with delayed wound breakdown and infection. Radiation brain injury occurred in 4 cases (14%), and each resolved with medical therapy.

CONCLUSIONS

This study shows that resection combined with Cs-131 CTBT resulted in significantly improved local control with acceptable complications in patients with recurrent aggressive meningiomas when compared with the prior treatment at the same site.