Current Imaging Techniques for and Imaging Spectrum of Prostate Cancer Recurrence and Metastasis: A Pictorial Review

Abstract

Relapsing level of prostate-specific antigen (PSA) after initial curative-intent local therapy for organ-confined prostate cancer is often the first sign of recurrence. However, PSA level recurrence does not enable accurate differentiation of locally recurrent tumor from metastatic disease or a combination of both. Metastatic prostate cancer most frequently involves bones and lymph nodes, followed by other organs such as the liver, lung, pleura, adrenal gland, ureter, peritoneum, penis, testis, and meninges. Conventional imaging including CT and bone scintigraphy has long been the standard of care but has limited sensitivity in depicting early local recurrence or metastatic disease. Multiparametric MRI has been shown to be more sensitive in detecting locally recurrent tumor in the prostatectomy bed as well as in situ recurrence in a prostate gland that has been treated with radiation therapy or thermal ablation. In addition, lesions detected with multiparametric MRI may be amenable to targeted biopsy for definitive diagnosis of recurrence. PET/ CT or PET/MRI using the U.S. Food and Drug Administration (FDA)-approved tracers carbon 11 choline or fluorine 18 fluciclovine has demonstrated markedly increased sensitivity and specificity for diagnosis of early metastatic disease such as small-volume lymph node metastasis, as have a range of investigational gallium 68 prostate-specific membrane antigen (PSMA) radioactive PET tracers. With recent advances in imaging modalities and techniques, more accurate early detection, localization, and characterization of recurrent prostate cancer have become possible. The authors present a contemporary review of the strengths and limitations of conventional and advanced imaging modalities in evaluation of patients with recurrent prostate cancer and a systematic review of the clinical and imaging features of locally recurrent and metastatic disease. ©

Role of theranostics in thoracic oncology

“…To this end, the detection of metastatic tumors within the thorax would provide physicians with the ability to more effectively treat a patient by being able to identify and remove otherwise invisible tumors. Others have shown the efficacy of radiolabeling the prostate-specific membrane antigen (PSMA) (30,31). Indeed, in our own trial (NCT04216134) we have used 68 Ga conjugated to PSMA and been able to effectively determine the presence of prostate cancer metastases in the thorax where the standard-of-care technique using 18 FDG did not (Figure 1).…”

A pictorial review of the less commonly encountered patterns of metastatic prostate carcinoma

“…Response to treatment is usually poor. Hepatic metastatic lesions are best seen in the portal venous phase as they are typically hypo-vascular, but they may sometimes show rim enhancement [12,13].…”

Non-Prostate Cancer Tumours: Incidence on 18f-Dcfpyl Psma Pet/Ct and Psma Expression Characteristics in 1445 Patients.

“…[1] Imaging of prostate cancer both at initial staging and at recurrence has been revolutionized by the advent of PET tracers targeted to prostate speci c membrane antigen (PSMA) which have shown superiority in comparison with conventional imaging comprising CT and bone scan. [2][3][4] PSMA is a transmembrane glycoprotein with high expression in most prostate cancer cells although also can sometimes be expressed in endothelial cells in non-prostate cancer tumor neovascularization. [5] There are several PSMA PET probes available, of which Gallium 68 probes are most widely used.…”