Is it reasonable to treat a solitary plasmacytoma of the lung parenchyma with SBRT?

I have only treated one patient with solitary plasmacytoma of the lung over the past 15 years of doing lung SBRT. It is an extremely rare and unusual disease presentation for myeloma. Given the radiosensitivity of myeloma, I opted for 30 Gy in 5 fractions, which resulted in a completed response in t...