68Ga-PSMA imaging of metastatic breast cancer

Abstract

68 Ga-labelled prostate-specific membrane antigen (PSMA) is rapidly emerging as a significant step forward in the diagnosis of recurrent prostate cancer, based on the fact that PSMA is a type II transmembrane protein with high expression in prostate carcinoma cells [1,2]. Recently it has been demonstrated to accumulate in metastatic clear-cell renal cell carcinoma [3] and interestingly several studies have provided evidence that PSMA is also expressed in the tumour-associated vasculature of primary breast cancers and distant metastases [4,5].We report the case of a 33-year-old woman with metastatic breast carcinoma who underwent 68 Ga-PSMA and 18 F-FDG PET/CT imaging for restaging and evaluation of the most appropriate therapeutic option. Images demonstrated intense and extensive skeletal uptake in the axial and appendicular skeleton with liver metastases.Concordance of 68 Ga-PSMA and 18 F-FDG lesions suggests that 68 Ga-PSMA may provide helpful prognostic information. Furthermore, 68 Ga-PSMA-avid metastatic sites may in future aid in selecting tumours with high PSMA expression for PSMA-directed therapy.

Prostate-Specific Membrane Antigen–Targeted Radiohalogenated PET and Therapeutic Agents for Prostate Cancer

“…The localization of a radiotracer in those cancers appears to be based on PSMA expression in tumor neovasculature (61). Clear cell renal cell carcinoma (62)(63)(64) and cancers of the thyroid (65), breast (66), and colon (67) are among the tumor types reported to have PSMA-targeted radiotracer uptake. With thoughtful, prospective trials to define the clinical utility of PSMA-targeted imaging in these cancers, PSMA-targeted imaging and therapy may prove to have broad implications in the field of oncology.…”

Imaging of Nonprostate Cancers Using PSMA-Targeted Radiotracers: Rationale, Current State of the Field, and a Call to Arms

“…Early human clinical studies demonstrated activity in breast tissue (22) and breast carcinoma using 111 In-J591 (23) planar imaging, as well as 68 Ga-PSMA-HBED-CC (N,N9-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N9-diacetic acid) PET/CT ( Fig. 1) (20,(23)(24)(25)(26). For instance, Sathekge et al demonstrated PSMA expression in 84% of 81 suspected metastatic lesions in 19 breast carcinoma patients who were undergoing PSMA-targeted PET imaging (20).…”

“…Expression in Nonprostate Cancers 1%) (2,8,16,18,21) 74/99 (75%) (2,9,16,18,54)111 In J591 (23,24);68 Ga HBED-CC(20,25) NSCLC 66/420 (16%)(2,15,16,30,31,54) 222/374 (59%)(8,9,30,31,33) …”

Detection of 18F-FDG PET/CT Occult Lesions With 18F-DCFPyL PET/CT in a Patient With Metastatic Renal Cell Carcinoma

“…In aggregate, our findings in this patient with metastatic clear cell RCC are suggestive that 18 FDCFPyL may able to identify more lesions and has higher tumor uptake than 18 F-FDG. Although a significant body of work has examined the role of 18 F-DCFPyL and other small molecule inhibitors targeted against PSMA in the detection of prostate cancer [1][2][3][4], the use of such radiotracers for non-prostate applications has been limited to date [5,6]. This is despite the fact that PSMA is highly expressed on the tumor neovasculature of many solid tumors, including RCC [7,8].…”