GBM as most know is a very malignant cancer that even with the best techniques we have had difficulty treating with only limited success.
Implants have been used before as UCSF with some apparent success but high risk of necrosis and long term need for steroid therapy. They were though able to achieve some long term controls as well. The gliadel wafers have been around and usually have been reserved for recurrence. I have on occasion treated with them placed up front and I think they definitely improve the response and response duration. I have not been real successful at convincing the neurosurgeons in using them upfront. Good reason is there is no significant data. GBM is one of those cancers where the results are poor enough in my opinion to "role the dice" since the results with Standard of Care are so poor.
There have been enough advances recently and with better radioactive Isotopes to try and use all modalities upfront to improve results ie hitting it with everything we have or shotgun approach. In this cancer I approve of this approach, particularly in patients who are incompletely resected , but also in apparent gross total resections. Hopefully it is done as part of a study and given the usual clinical course of GBM it should not take long to see improvement, if any.