Could Proton therapy be an alternative?
Not aware of proton therapy, but in 2014 there was a report of a 90 plus year old male, felt too fragile to undergo surgery who was treated with stereotactic body radiation therapy with success. As of now, surgery is the treatment of choice for parathyroid hormonal excess either caused by a single adenoma (tumor of the gland) or diffuse parathyroid hyperplasia involving all glands, in which case the surgeon will excise 3 1/2 of the glands.