Authors: Peter Nakaji, MD, FAANS; Emad Youssef, MD; Christopher Dardis, MD; Kris Smith, MD; Dilini Pinnaduwage, PhD; David Brachman, MD (Phoenix, AZ)

Resection alone is typically insufficient for recurrent previously irradiated intracranial neoplasms and repeat adjuvant external beam radiation treatment (EBRT) is often contraindicated. For these reasons we prospectively evaluated the combination of maximum safe resection (R) and surgically guided collagen tile brachytherapy (TBT) in this cohort of patients. Methods: From 2/13 to 2/18 recurrent previously irradiated intracranial neoplasms were treated on a single arm, multi-histology study (ClinicalTrials.gov, NCT#03088579). At resection completion biocompatible collagen tiles imbedded with Cs 131 sources were permanently implanted in the operative bed under surgical guidance. The device offset sources from brain surface and delivered 60-80 Gy 5 mm deep to the operative bed. No additional local therapy was given without progression. Results: 79 recurrent tumors in 74 patients were treated: 40 high grade gliomas (HGG) (10 grade 3, 30 grade 4), 23 meningiomas (1 grade 1, 20 grade 2, 2 grade 3), 12 metastases, and 4 “other”. Average prior same site surgeries were 2 (range 0-4); median prior EBRT dose 70 Gy. Median age 61 years; 31 females/43 males. Average implantation time was 5 minutes. At median follow-up of 13.4 months (range 1-54.6 mo.), median treatment site local control (LC) was 12 months for HGG, 48.5 months for meningioma, and median time to LC time has not been reached for metastasis. Median overall survival (OS) was 12.0 months for HGG, 49.2 months for meningioma, and 12 months for brain metastasis. Adverse surgical events were wound infection in 2/79 (2.5%), dural closure breakdown in 2/79 (2.5%), and procedure related hematoma in 1/79 (1.3%). Symptomatic radiation brain changes occurred in 6/79 (7.6%) cases, all treated medically. Conclusion: Surgically targeted tile brachytherapy exhibits good LC and OS with complication rates comparable to existing treatments. This treatment could expand the therapeutic options for this difficult cohort of patients.
Rosenblum-Mahaley Clinical Research Award