前立腺癌放射線治療後に発生した恥骨radiation-induced sarcomaの1例

A case of radiation-induced sarcoma after radiation therapy for prostate cancer

前立腺癌の根治療法の1つに放射線治療があり，多くのstageで放射線治療が実施されている。前立腺癌放射線治療において，旧来の二次元照射では二次発癌の発生率が上昇することが報告されている^1-3）。近年一般的に用いられている三次元原体照射や強度変調放射線治療においてはあまり報告がない。

A case of radiation-induced sarcoma was reported. Ten years after three-dimensional conformal radiation therapy for prostate cancer, a tumorous lesion around the right pubic bone in the irradiation field was found, and a biopsy revealed a well-differentiated osteosarcoma. There was no recurrence of prostate cancer. The patient was diagnosed with radiation-induced osteosarcoma, and underwent a radical resection. Secondary carcinogenesis is a concern for patients with prostate cancer treated with radiation therapy because of the long-term prognosis.