Campbell Scott P, Baras Alexander S, Ball Mark W, Kates Max, Hahn Noah M, Bivalacqua Trinity J, Johnson Michael H, Pomper Martin G, Allaf Mohamad E, Rowe Steven P, Gorin Michael A
The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Ann Nucl Med. 2018 Jan;32(1):69-74. doi: 10.1007/s12149-017-1216-x. Epub 2017 Oct 24.
To explore the clinical utility of PSMA-targeted F-DCFPyL PET/CT in patients with metastatic urothelial carcinoma.
Three patients with metastatic urothelial carcinoma were imaged with F-DCFPyL PET/CT. All lesions with perceptible radiotracer uptake above background were considered positive. Maximum standardized uptake values were recorded for each detected lesion and findings on F-DCFPyL PET/CT were compared to those on conventional imaging studies. To further explore PSMA as a molecular target of urothelial carcinoma, RNA-sequencing data from The Cancer Genome Atlas were used to compare the relative expression of PSMA among cases of bladder cancer, prostate cancer, and clear cell renal cell carcinoma. Additionally, immunohistochemical staining for PSMA was performed on a biopsy specimen from one of the imaged patients.
F-DCFPyL PET/CT allowed for the detection of sites of urothelial carcinoma, albeit with low levels of radiotracer uptake. Analysis of RNA-sequencing data revealed that bladder cancer had significantly lower levels of PSMA expression than both prostate cancer and clear cell renal cell carcinoma. Consistent with this observation, immunohistochemical staining of tissue from one of the imaged patients demonstrated a low level of neovascularization and nearly absent PSMA expression.
The relatively scant expression of PSMA by urothelial carcinoma likely limits the utility of PSMA-targeted PET imaging of this malignancy. Future research efforts should focus on the development of other molecularly targeted imaging agents for urothelial carcinoma.
探讨PSMA靶向的F-DCFPyL PET/CT在转移性尿路上皮癌患者中的临床应用价值。
对3例转移性尿路上皮癌患者进行F-DCFPyL PET/CT检查。所有放射性示踪剂摄取高于背景且可察觉的病变均视为阳性。记录每个检测到的病变的最大标准化摄取值，并将F-DCFPyL PET/CT的检查结果与传统影像学检查结果进行比较。为进一步探究PSMA作为尿路上皮癌的分子靶点，利用癌症基因组图谱的RNA测序数据比较膀胱癌、前列腺癌和透明细胞肾细胞癌病例中PSMA的相对表达。此外，对其中一名接受检查患者的活检标本进行PSMA免疫组化染色。
F-DCFPyL PET/CT能够检测到尿路上皮癌的病灶，尽管放射性示踪剂摄取水平较低。RNA测序数据分析显示，膀胱癌的PSMA表达水平显著低于前列腺癌和透明细胞肾细胞癌。与该观察结果一致，对其中一名接受检查患者的组织进行免疫组化染色显示新生血管形成水平较低且几乎不存在PSMA表达。
尿路上皮癌中PSMA表达相对较少，这可能限制了PSMA靶向PET成像在这种恶性肿瘤中的应用。未来的研究工作应聚焦于开发其他针对尿路上皮癌的分子靶向成像剂。
