IsoRay (NYSE:ISR) said today that the FDA requested additional data on the company’s pending 510(k) application for its GammaTile radiation therapy system.

The Richland, Wash.-based company’s GammaTile is a radiation system using Cesium-131 radiation seeds embedded in a collagen ’tile’ which is designed to be placed in surgical margins at the time of surgery.

“This is a good outcome for the novel GammaTile product. With the completion of additional testing anticipated by the end of 2017, we project potential 510(k) clearance of the GammaTile product in the 1st half of 2018 which would allow for the NTAP application to be approved in 2018 during the annual review process. GammaTile addresses a large unmet clinical need for the treatment of recurrent brain tumors and we’re pleased to be advancing on the path to commercialization of this important product,” IsoRay chair & CEO Tom LaVoy said in a press release.

IsoRay said that as a result of the request, it will be resubmitting a New-Technology Add-On Payment application in the fall of 2017 for the next annual review cycle. The company said it, and it’s co-applicant GammaTile received ICD-10-PCS coding for the GammaTile to allow for Medicare reimbursement once it receives FDA 510(k) approval.

Late last month, IsoRay released data from a study of its Cesium-131 brachytherapy for treating patients with large brain metastases, touting a 100% freedom from local progression.