PSMA: A Specific Biomarker for Prostate Cancer Imaging?

Prostate cancer (PCa) is a worldwide common malignancy in men with a progressive increase in trend. About 30-40% of cases turned out to be biochemical recurrence after the definitive treatment for localized PCa. In addition, for those with metastatic castration-resistant PCa, nuclear molecular theranostics using prostate-specific membrane antigen (PSMA), radio-ligands has played an increasing role. Ga-68 labeled PSMA 11 is the most common one in the clinical investigations, especially coupling with Lu-177 PSMA for PCa precision therapy. However, PSMA is also expressed in certain normal tissues, benign and non-PCa malignant tumors, causing potential pitfalls in clinical management. F-18 labeled PSMA serves as an alternative for PCa imaging with different biophysical characteristics from Ga-68 labeled PSMA. Its implications in practice, especially equipped with a new positron emission tomography/computed tomography or positron emission tomography/magnetic resonance imaging modalities are worth noting.

關鍵字

PSMA ； prostate cancer (PCa) ； biochemical recurrence

並列摘要

前列腺癌是全球男性常見癌症，其發生有逐年上升趨勢。一般在做完腫瘤初步處置後，仍有30-40%的病人會出現「生化性復發現象」。同時，針對「轉移性去勢抗性」（metastatic castration-resistant prostate cancer; mCRPC）病人的處理也是目前臨床棘手問題。利用前列腺特異膜性抗原（prostate-specific membrane antigen, PSMA）進行核醫分子診療在這些方面的協助日益受重視。其中，鎵-68標誌PSMA-11在臨床觀察經驗最多，特別是搭配鎦-177進行前列腺癌診療目的趨向逐為顯學。由於PSMA標誌在某些正常組織、良性或非前列腺癌惡性腫瘤也有攝取現象，其所代表的臨床意義值得探討。另一方面，氟-18標誌PSMA也在近年應運而生，其生物物理特性與鎵-68標誌者有所區別，能否作為鎵-68PSMA的替代品，特別是搭配新型正子電腦斷層攝影（positron emission tomography/computed tomography, PET/CT）或正子磁振造影（PET/MR [magnetic resonance]），也值得進一步觀察。

並列關鍵字