What are the long-term effects of radiation therapy on bone?

Supress marrow prod.: It can suppress bone marrow function as long as the bone was in the treated field. Extra care taken by radiation oncologist to avoid unneeded bone marrow in the treatment field specially if there is going to be chemotherapy in the treatment plan. Bone will also be less flexible, hence more brittle.

Depends : The bone marrow is the most sensitive tissue in bone, and is responsible for making important blood cells. Radiation can suppress these tissues from working depending on the dose and site of bone irradiated. The bone also can weaken if irradiated to high doses, making it more susceptible to fracture.

Supress functions : Bone marrow has many important roles including production of blood cells responsible for immunity, in other blood products. Radiation can suppress normal bone marrow function. It can scar bone marrow. Bone can lose some of its flexibility / tensile strength, so it may fracture easier. Depending on the dose, radiation field, vascularity, there is an a rare but possible complication of necrosis.