PET and prostate cancer

Abstract

The diagnosis of prostate cancer leaves some questions without answers. The different diagnostic techniques are limited in three situations: (1) staging of the tumour: identification of node involvement, (2) quantification of the tumour volume and its location inside the gland, (3) premature identification of relapse after radical treatment. These are the three problems that we need to consider in the diagnosis of prostate carcinoma. Imaging techniques can tell us the morphological alterations in the structures and organs. Positron emission tomography (PET) introduces a new way of identifying damage by counting metabolic activity. The tracers are substances that are marked with a radioactive molecule that is picked up more readily by the tumours. The presence of these substances in a set anatomic zone means higher consumption and therefore more metabolic activity. The radiotracer most frequently used in PET is glucose marked with fluoride 18. The first studies with marked glucose and prostate tumours started at the end of the 1990s. There are many contradictions in the results of these studies due to renal elimination, which produces an accumulation in the urinary tract and does not correctly show the prostate zone and iliobturator nodes area, and its capitation by zones with inflammatory process or prostatic hyperplasia. Choline is a substance that is present in cellular membranes. When it is marked with carbon 11, it changes to a new tracer. This radiotracer has affinity with prostate damage and allows the better differentiation of malignant from benign processes. It also has the advantage of the absence of renal elimination. Trials that used choline marked with carbon 11 (11C choline) are beginning to obtain very promising results. This union of a method that identifies metabolic activity with an imaging technique increases the sensitivity in the diagnostic test and can help find the exact location of the 11C choline deposits. The PET-CT combines the PET with computerised tomography. The 11C choline PET-CT is presented as a promising technique for answering the three problems mentioned above.

11C‐Choline positron‐emission tomography/computed tomography and transrectal ultrasonography for staging localized prostate cancer

“…Since the introduction of PET/CT several authors have reported the usefulness of PET in staging and re-staging of prostate cancer [14][15][16][17]. However, the available data and the few patients assessed in previous reports do not permit a judgement of the real value of this imaging method in staging prostate cancer.…”

Imaging of Prostate Cancer

“…9) [76][77][78][79][80]. Fluorodeoxyglucose (FDG), the most commonly used PET tracer, was reported to be ineffective for the initial staging of prostate cancer because most primary prostate cancer lesions were not detected by FDG-PET [81].…”

Diagnosis of prostate cancer via nanotechnological approach

“…Prostate-specific membrane antigen (PSMA) has been selected as a target in the detection of prostate cancers with these techniques. [66][67][68][69][70][71][72] A notable molecular imaging technology is 68Ga-PSMA PET/CT, which targets PSMA as the biomarker. The FDA has recently approved a clinical trial of this technology.…”