Published September 14, 2021
University College London, UK
2021 ARRS Lee F. Rogers International Fellow in Radiology Journalism
The role of imaging in prostate cancer detection and staging is of paramount importance, as it needs to provide physicians with accurate information on both the presence and extent of the disease—avoiding overdetection and overtreatment at the same time.
As far as prostate MRI is concerned, remarkable advances have been made over the last decade, and several data support the role of this technique for diagnosis, active surveillance, and in the posttreatment setting.
We know that the measurement of prostate specific antigen (PSA) level alone is not enough because radiological progression can occur without an increase in PSA level, due to the molecular heterogeneity of prostate cancer.
An area of particular interest in prostate cancer is represented by next-generation imaging techniques, which include both PET/CT or PET/MRI using different radiopharmaceuticals (e.g., choline or acetate) and whole-body MRI.
When conventional imaging is equivocal, next-generation imaging can investigate the increased metabolism and vascular changes in prostate cancer and help in the detection and characterization of additional sites of disease, which could potentially change management.
In order to improve the assessment of advanced prostate cancer and patient survival, next-generation imaging (e.g., PET/MRI and whole-body MRI) can provide earlier detection of metastatic disease and predictive biomarkers for therapy selection, allowing us to assess treatment response and identify metastasis that can be biopsied for molecular or genomic characterization.
The 2020 guidelines from the American Society of Clinical Oncology on the optimum imaging strategies for advanced prostate cancer can be summarized as below:
- For clinical high-risk disease at initial diagnosis, the literature supports addition of next-generation imaging when conventional imaging (e.g., CT, radionuclide bone scan, or multiparametric prostate MRI) is equivocal or suspicious for metastatic disease.
- For biochemical evidence of recurrent disease after local therapy with negative conventional imaging, next-generation imaging is indicated to assess the presence of local or distant site and burden of disease to plan salvage therapy.
- For metastatic disease at initial presentation on conventional imaging, next-generation imaging may clarify the burden of disease and alter treatment plans.
- For nonmetastatic castrate-resistant prostate cancer, next-generation imaging can be considered to assess for unrecognized metastatic disease.
- For metastatic castrate-resistant prostate cancer with biochemical progression only, use of next-generation imaging is unclear and should be individualized, preferably as part of a clinical trial.
Additionally, on December 1, 2020, the FDA approved the first prostate specific membrane antigen-targeted PET imaging drug (68-Ga-PSMA-11) for patients with suspected prostate cancer metastasis whose disease is potentially curable with surgery or radiation therapy and for patients with suspected prostate cancer recurrence based on elevated serum PSA levels.
Unfortunately, there is still a lack of standardization of next-generation imaging in prostate cancer, and most physicians still rely on traditional imaging, as they may not be aware of the potential of these new imaging techniques.
Access to next-generation imaging is still highly limited, and insurance coverage for these tests remains highly variable. Until these barriers are overcome, the widespread use of next-generation imaging in prostate cancer parameters will be challenging.
Although there are still a number of challenges ahead, next-generation imaging will definitely play an increasing role in the management of prostate cancer—enabling assessment of treatment response and disease progression and aiding the delivery of precision oncology in patients with advanced prostate cancer.
The journey is only just beginning, but the future is definitely encouraging.
The opinions expressed in InPractice magazine are those of the author(s); they do not necessarily reflect the viewpoint or position of the editors, reviewers, or publisher.