We've had many patients treated with Optune with very good results. I have had several patients to wear it long past 6 months, in fact I have a few that have been wearing it 2-3 years and one at over 4 years. The prescription is good for 6 months and so it must be renewed at the end of this time. Some of my patients have actually had tumor regression and one had a CR after about a year on treatment with minimal side effects. It's nice to have something new to offer our GBM patients.