@audrey27 Almost all commercial insurance including Medicare Advantage will not cover focal treatments for prostate cancer (I know of none but could be exceptions). Applies to all cancer treatments considered experimental in the USA even if widely used in EU or other locations. Also unlikely to pay for Proton therapy, Fusion or mri biopsy, and even SBRT for first treatment. Plan to pay out of pocket or chose a covered treatment.
Some focal treatments are covered by classic Medicare and if Medicare pays any gap plan (G & N have replaced F & L for recent retirees) is required to pay per the policy. Gap plans regulated by CMS and do not make coverage decisions.