by PSM is a truncated cytoplasmic PSMA and its function is unknown. PSMA based theranostics approach for detection, staging, treatment, and follow-up of PC would appear to be highly valuable to achieve personalized PC treatment. strong class=”kwd-title” Keywords: Prostate cancer, biochemical recurrence, CT and MRI, PET Choline, 68Ga-PSMA PET-Theranostics Introduction Prostate cancer (PC) is the most common solid tumor in men and the third common cause of mortality among men of developed countries (Torre, 2015). Like other malignancies, accurate staging of PC is the fundamental step in A2A receptor antagonist 1 the selection of the most appropriate therapeutic strategy. Radical prostatectomy and radiation therapy are considered as primary therapy with curative intent for localized PC and systemic therapy for patients with metastases. Currently morphological imaging like ultrasound (US), computerized tomography (CT), magnetic resonance A2A receptor antagonist 1 imaging (MRI), functional imaging like bone scanning (BS) and hybrid imaging like choline based positron emission tomography and CT (PET/CT) are commonly used in diagnosis, staging and restaging of PC. But as a matter of fact these modalities have disappointing sensitivities (Heck et al., 2014) and no reliable imaging tool is available A2A receptor antagonist 1 for diagnosis of site of disease recurrence in patients with biochemical recurrence (Ceci et al., 2014). However, in recent years, Gallium-68 labeled Prostate Specific Membrane Antigen (68Ga-PSMA) has emerged with high diagnostic accuracy based on initial results (Eisenhut and Zechmann, 2012). In this mini-review we will discuss the limitations of existing imaging modalities and possible benefits of 68Ga-PSMA in various clinical settings among patients with PC. Diagnosis of Prostate Cancer As per current clinical practice based on recent guidelines, US guided biopsy is the most commonly used way with considerably high diagnostic yield for diagnosis of PC. However, in suspected PC patients with negative US guided biopsies; MRI is used as a standard imaging procedure to guide the targeted re-biopsies of suspected lesions. But some lesions might also be missed on MRI-guided biopsies and these are the patients who pose a diagnostic challenge. In such diagnostic dilemma, new PET based tracer like 68Ga-PSMA PET/CT is found to play an important role due to its high target to background ratio resulting in better delineation of tumor. In some preliminary studies using 68Ga-PSMA PET/CT, a high diagnostic yield was found for targeted fusion biopsies (Storzet al., 2015; Zettinig et al., 2015). TNM Staging of Prostate Cancer Tumor (T) Staging: In last decade MRI has emerged as a standard of care in local staging of PC like capsular breach and invasion of seminal vesicle. In current A2A receptor antagonist 1 days multi-parametric MRI (mpMRI) which includes T2 weighted images (T2WI C hypointense PC focus), dynamic contrast enhanced (DCE C high influx and washout of contrast in PC), diffusion weighted imaging (DWI C restricted diffusion with low ADC in PC) A2A receptor antagonist 1 and spectroscopy (MRS C shifted choline and citrate metabolism in PC) is assumed more accurate than MRI alone in local staging of PC (Futtereret al., 2006; Tan et al., 2012). mpMRI is considered to have high sensitivity and specificity for detection of aggressive PC as well. However, in some patients local changes after biopsy sampling like local bleed and inflammation might pose interpretation challenges to mpMRI. Introduction of simultaneous whole body PET/MRI has a promising role in staging of PC. Preliminary comparative studies using PET/MRI have shown better delineation of prostate lesions with 68Ga-PSMA than choline derivatives (Eiber et al., 2014). Furthermore, 68Ga-PSMA interpretation does not seem to be influenced by previous biopsies (Eiber et al., 2014). Nodal and Metastasis (N and M) Staging The fundamental goal of staging is to find nodal, bone or visceral metastasis as it Mouse monoclonal to BID assists the physicians in selecting.
