This CPB is revised to state that Supprelin LA histrelin acetate subcutaneous implant is considered medically necessary for central precocious puberty when criteria are met. This CPB is revised to state that Vantas histrelin acetate subcutaneous implant is considered medically necessary for treatment of prostate cancer when criteria are met. This policy revision is based upon the FDA-approved indications for Supprelin LA and Vantas.