Any radiation treatment has the potential to damage DNA in healthy cells. Which lists therapeutic uses of radiation based on the likelihood of affecting healthy cells in order from least likely to most likely?

deep external beam radiation therapy, brachytherapy, radiopharmaceuticals
radiopharmaceuticals, deep external beam radiation therapy, brachytherapy
brachytherapy, radiopharmaceuticals, deep external beam radiation therapy
radiopharmaceuticals, brachytherapy, deep external beam radiation therapy