Abstract
We report the use of heavy ion radiotherapy for a case of osteosarcoma in the pelvic bone of a 55-year-old man. Radiography revealed a radiolucent lesion with a pathological fracture in the right iliac bone. Computed tomography revealed that the tumor, measuring 14x12cm, was located in the iliac bone with infiltration within and beyond the pelvis. Magnetic resonance imaging revealed that the tumor was located in the iliac bone and had invaded the sacrum. The tumor was subsequently diagnosed as an osteoblastic osteosarcoma by needle biopsy. Because we thought that surgery would be excessively invasive and lead to loss of motor function, we selected heavy ion radiotherapy after doxorubicin and cisplatin chemotherapy. The 2-year course after heavy ion radiotherapy was uneventful, without recurrence or distant metastasis.
It is difficult to treat osteosarcomas in the pelvic bone because of associated anatomical problems and potential loss of function after surgery. Carbon ion radiotherapy has been reported to be effective and safe for bone sarcomas. However, high-grade bone sarcomas such as osteosarcoma have been reported to have a high recurrence rate. The long-term outcomes of carbon ion radiotherapy for bone sarcomas are uncertain. Although carbon ion radiotherapy should be considered for treatment of bone sarcomas, its indications should be assessed carefully, especially in high-grade malignancies.
