Imaging for Metastasis in Prostate Cancer: A Review of the Literature

Abstract

Background: Initial staging and assessment of treatment activity in metastatic prostate cancer (PCa) patients is controversial. Indications for the various available imaging modalities are not well-established due to rapid advancements in imaging and treatment. Methods:We conducted a critical literature review of the main imaging abnormalities that suggest a diagnosis of metastasis in localized and locally advanced PCa or in cases of biological relapse. We also assessed the role of the various imaging modalities available in routine clinical practice for the detection of metastases and response to treatment in metastatic PCa patients. Results:In published clinical trials, the most commonly used imaging modalities for the detection and evaluation of therapeutic response are bone scan, abdominopelvic computed tomography (CT), and pelvic and bone magnetic resonance imaging (MRI). For the detection and follow-up of metastases during treatment, modern imaging techniques i.e., choline-positron emission tomography (PET), fluciclovine-PET, or Prostate-specific membrane antigen (PSMA)-PET provide better sensitivity and specificity. This is particularly the case of fluciclovine-PET and PSMA-PET in cases of biochemical recurrence with low values of prostate specific antigen. Conclusions:In routine clinical practice, conventional imaging still have a role, and communication between imagers and clinicians should be encouraged. Present and future clinical trials should use modern imaging methods to clarify their usage. Inclusion and Exclusion CriteriaOnly original manuscripts and reviews published in indexed and peer-reviewed journals and written in English between August 1999 and December 2019 were considered. Cross-sectional studies, case reports, published abstracts, dissertation materials, and conference presentations were excluded. Of 1,725 potential articles from the literature search, 105 were selected, including 16 literature reviews, 5 meta-analyses, 11 guidelines or position papers, and 73 original articles.

Whole-Body MRI vs. PET/CT for the Detection of Bone Metastases in Patients With Prostate Cancer: A Systematic Review and Meta-Analysis

“…Importantly, that review suggested that WMBRI could be more sensitive than PET/CT for visceral metastases (28)(29)(30) and small hepatic and brain metastases (28,31,32), but WBMRI could be associated with more false-positives that PET/CT for bone metastases because bone marrow edema caused by benign lesions can appear as metastases on the apparent diffusion coefficient (ADC) map (28). A review highlighted that modern PET/CT protocols have a better diagnostic value than MRI for the detection of PCa metastases but that MRI still has a role to play (33). Since the present meta-analyses only examined bone metastases, this edema from benign lesions might explain, at least in part, why WBMRI fared less well than PET/CT.…”

A novel tool for improving the interpretation of isotope bone scans in metastatic prostate cancer

“…Significant advances have been made in imaging for metastatic prostate cancer, with increasing use of PSMA-PET and WBMRI adding increased sensitivity and anatomical delineation of metastases. 4 Despite this, bone scans will remain an affordable method that allows treatment decisions to be made based on the volume of disease present. Novel imaging tools may not be affordable to or available in many countries.…”

“…Although IBS has limited sensitivity (79%) and specificity (82%) for detection of bone metastases, 3,4 it is still the most frequently used method for diagnosis to assess skeletal involvement in prostate cancer. A validated endpoint in mCRPC trials is bone scan progression, which relies on the appearance of new lesions, as proposed by the prostate cancer working group 3 (PCWG).…”

“…6 This situation has paradoxically become more complicated with the introduction of newer functional imaging techniques. 4,6,7 Figure 1. Whole-body isotope bone scan (IBS): anterior (left) and posterior (right) views showing widespread bony metastases involving the pelvis, femora, ribs, spine, sternum, and skull.…”

Role of Metastasis Suppressor KAI1/CD82 in Different Cancers

“…Prostate cancer (PC) is the most frequently diagnosed cancer in 105 countries in men and is the most common cause of death from malignant tumours [ 56 ]. Most PCs are curable, but metastatic forms are associated with lower survival rate; therefore, imaging is needed to detect and track metastases evolution during treatment [ 57 ].…”