For recurrent glioblastoma treated with combined re-irradiation and bevacizumab, how long do you continue bevacizumab?

In the event of recurrent GBM, for example, if i.e. fSRT regimen like 30 Gy/5fx to be used for salvage, would not exceed more than 12 doses (6 cycles) of bevacizumab max. Even in the pseudo-response setting, the toxicity far outweighs the benefit beyond this.