Prostate-specific membrane antigen (PSMA) is a protein that is expressed predominantly in normal prostate epithelial cells and in most adenocarcinomas of the prostate (Cap) and in virtually all Cap metastases.
Currently prostate-specific membrane antigen (PSMA) is showing promise both as an imaging and therapeutic target for occult prostate cancer metastases.
Eighty-four tumor metastasis related genes were screened in si-PSMA LNCap cells (PSMA silenced by siRNA)/LNCap cells and in PC-3/LNcap cells, respectively.
<sup>68</sup>Ga-PSMA-HBED-CC SUVmean values of distant metastases proved significantly higher (mean, 6.86, SD, 5.68) when compared to those of primary or local recurrences (mean, 2.45, SD, 2.55, p = 0.04) or involved lymph nodes (mean, 3.18, SD, 1.79, p = 0.011).
Six patients with iodine-negative and F-FDG-positive metastasized DTC (mean TG, 1616 ng/mL) received 71-93 MBq of the Ga-labeled PSMA ligand and underwent PET/CT at 62 ± 7 minutes p.i.. Tumor accumulation capacity of the tracer and the detection rate of local recurrences and metastases were compared with F-FDG.
Prostate-specific membrane antigen (PSMA) is increasingly being recognized as a novel target for the PET imaging of prostate cancer (PCa) and Ga-DKFZ-11 (Ga-PSMA) has been suggested as a novel tracer for detection of PCa relapses and metastases.
It seems as 68Ga-PSMA PET/CT is better than PET/CT in prostate cancer to detect primary prostate lesions, initial metastases in the lymph nodes and recurrence.
Ga PSMA PET/CT done in view of increased PSA levels and clinically suspicious hard lesion in prostate showed primary lesion in left side of prostate with metastases to the right temporal bone.
In particular, we focus on the utility of PSMA-PET for diagnostic evaluation of isolated or limited metastases planned for local surgery or radiation, as well as the potential utility of PSMA-PET for therapeutic response assessment in patients receiving stereotactic ablative body radiotherapy (SABR).
Ga prostate-specific membrane antigen (PSMA) ligand PET/CT performed for localization of recurrent disease revealed bilateral metastases to the testes.
<b>Conclusion:</b> Synchronous <sup>68</sup>Ga-labeled prostate-specific membrane antigen-avid malignancies were rare (0.7%) in PC patients; atypical lesions were more commonly unusual PC metastases (1.0%) or benign (3.1%).
All primary tumours showed PSMA expression on immunohistochemistry (5-90% expression), as well as all available specimens of local recurrence and distant metastases.
PSMA is significantly overexpressed in the neovasculature of DTCs compared with normal and benign thyroid nodules specifically with increased expression in RAIR carcinomas and distant metastases.
This study suggests that Ga-PSMA PET/CT is useful for lymph node and metastases staging in high-risk prostate cancers, whereas its utility for staging of disease in the prostate is limited.
To evaluate the diagnostic performance of [<sup>68</sup>Ga]Ga-PSMA<sup>HBED-CC</sup> conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions.
<sup>68</sup>Ga-PSMA PET/CT had a high detection rate of PCa recurrence outside the prostatic fossa in pts. being considered for salvage RT (22.4% PET-positive pelvic lymph nodes and 4.1% distant metastases).
<sup>68</sup>Ga-PSMA is the diagnostic positron-emitting theranostic pair with the beta emitter Lutetium-177 PSMA (<sup>177</sup>Lu-PSMA) and alpha-emitter Actinium-225 PSMA (<sup>225</sup>Ac-PSMA) which can both be used to treat PSMA-avid metastases of prostate cancer in the molecular tumor-targeted approach of theranostic nuclear oncology.