前立腺癌の核医学診断と治療（PSMA theranostics）

Nuclear medicine diagnosis and treatment of prostate cancer：PSMA theranostics

PSMAは前立腺特異的膜抗原といわれ，前立腺癌細胞で高発現しており，診断と治療を一体化した「セラノスティクス」の鍵とされる。前立腺癌の核医学検査・治療法に⁶⁸Ga-PSMA-11 PETや¹⁷⁷Lu-PSMA治療があり，⁶⁸Ga-PSMA-11 PETの従来検査に対する診断能の優位性，¹⁷⁷Lu-PSMA治療の従来治療に対する優位性（無増悪生存率や全生存率の向上）が報告されており，現在は去勢抵抗性前立腺癌に対する国際共同治験（第Ⅲ相試験）が行われている。本稿ではPSMAの基本，⁶⁸Ga-PSMA-11，¹⁷⁷Lu-PSMA，今後の展望について解説を行う。

⁶⁸Ga-PSMA-11 and ¹⁷⁷Lu-PSMA are emerging nuclear medicine tools for diagnosing and treating prostate cancer. PSMA, highly expressed in prostate cancer cells, plays a crucial role in theranostics. ⁶⁸Ga-PSMA-11 PET/CT has demonstrated superior sensitivity and specificity compared to conventional methods, with safety validated in Japan. ¹⁷⁷Lu-PSMA offers effective treatment by targeting PSMA-expressing cells, improving progression-free and overall survival in international trials. Additionally, research into alpha-emitting radionuclides, such as ²²⁵Ac-PSMA and ²¹¹At-PSMA, shows promising potential. These advancements mark significant progress in prostate cancer management, integrating diagnosis and therapy into a single approach.