Do you think my radiation therapy caused osteoencrosis in my hips?

Maybe. Radiation therapy has some side effect and may cause bone to weaken and can cause the bone to fracture .
It is possible. The hips are sensitive to the long-term effects of radiation. The dose to the hips, in which there is an increased risk of fracture, typically starts at 45 gy. You will need to ask your radiation oncologist to review your treatment plan to know the dose they received.