The increasing importance of imaging in the era of advanced cancer therapies
The increasingly pivotal role of medical imaging in the detection and management of some of the world’s most common cancers was highlighted during GE HealthCare’s Oncology Symposium at the 2024 European Congress of Radiology in Vienna. Professor Annemiek Snoeckx from Antwerp University Hospital discussed the importance of screening programmes for lung cancer. This was followed by a presentation from Professor Evis Sala of Gemelli University Hospital in Rome, who focused on the role of imaging in the management of prostate cancer.
Detecting early, saving lives: the power of lung cancer screening
Professor Snoeckx, Chair of Radiology at Antwerp University Hospital and an associate professor at the University of Antwerp in Belgium, outlined the importance of screening programmes in saving the lives of lung cancer patients.
Lung cancer has the highest mortality rate in Europe, and new approaches are now being successfully developed to tackle this issue and target populations at risk. Many of these programmes are using risk prediction models to redefine the eligibility criteria of participants, moving away from a two-category approach – based simply on smoking history and age – to multi-factorial criteria, including family history, BMI, COPD and asbestos exposure. As more data becomes available from these screening programmes, it will be possible to refine the models further and, with the aid of AI, predict the risk of lung cancer more accurately in specific populations.
Screening of populations considered ‘at risk’ is currently performed using low dose CT, but this still involves radiation exposure. Balancing potential benefits and harm is obviously essential in any screening programme, and Prof. Snoeckx predicts ‘ultra-low’ dose CT will be used in future screening programmes, with research into this approach already in progress. She highlights potential new generation technologies for scanners, new types of scanners, and new image reconstruction techniques, as well as new hardware.
With regard to reviewing images, the assessment of growth of a lung cancer nodule will continue to focus on measuring volume, rather than diameter. Imaging tools are now available that give precise and accurate volumetric measurement in a reproducible way, aiding the review process. These and other advances in imaging technologies are driving the evolution of lung cancer screening programmes through more standardised approaches, but progress is being slowed due to a number of challenges, including:
- the problem of defining high-risk populations, and accessing and engaging ‘hard to reach’ participants;
- the rate and implications of false positives, which are improving with developments in software and nodule guiding management systems, however, rates are still high;
- over-diagnosing cancer, extending patient lead times when there may be no symptoms or death resulting from the cancer identified;
- and the issue of other thoracic or extra-thoracic incidental findings during screening, and how to manage them.
The potential for using biomarkers to detect early lung cancers is also a possibility. However, this is still somewhat in the future, as a new perspective may be needed to look for biomarkers in the 50 per cent of lung cancer cases that do not currently meet screening selection criteria, such as non-smokers and those exposed to environmental causes. If biomarkers can be identified to select screening participants, it could help to destigmatise the process and aid recruitment.
In summary, Prof. Snoeckx implored radiologists in the ECR audience to not stay within the realms of LDCT screening, reading and reporting, but to ‘come out of the dark’ and take a leading role in life-saving lung cancer screening programmes. Radiologists need to lead screening programmes by developing the necessary quality assurance frameworks, raising public awareness, undertaking implementation research and driving innovation. This will lead to further technological advances, better data interpretation, more efficient screening programmes and, ultimately, reduced mortality rates.
The impact of imaging in prostate cancer management
Professor Evis Sala, Chair of Radiology at Gemelli University Hospital (Fondazione Policlinico Universitario Agostino Gemelli) in Rome, Italy, delivered the symposium’s second presentation, turning attention to the role imaging plays in the management of prostate cancer, from screening and diagnosis to therapy and predicting outcomes.
Medical imaging plays a critical role in patient care pathways for prostate cancer, and Prof. Sala led attendees through some of the key studies that highlight its importance for detecting and managing prostate cancer. She also discussed how recent technological advances – not just in terms of hardware, but also software improvements and AI support – are enhancing efficiency across multiple workflows.
The UK-funded PROMIS study looked at the role of multiparametric MRI (mpMRI) in guiding biopsies,1 demonstrating that mpMRI-guided transrectal ultrasound scan (TRUS) biopsies could detect 18 per cent more cases of clinically significant cancer compared to standard biopsies. Similarly, the 2021 NEJM study by Ekland et al. showed that it also reduced biopsy rates by 36 per cent, with no difference in detection rates of significant cancers compared to standard biopsy approaches. 2 Perhaps most strikingly, this study found the detection of indolent cancers (GG1) was reduced by 66 per cent when biopsies were guided by mpMRI. These studies suggest mpMRI-guided biopsy is safe, invasive procedures are reduced, and there is less over-diagnosis.
There is also reason to be cautious of over-reliance of PSA (prostate specific antigen) tests as a screening tool for prostate cancer. Evidence from several studies – such as Moore (2023)3 – demonstrate that MRI has value as a screening tool independently from PSA results. In Moore’s study of 303 participants, more than half the men with clinically significant disease had a PSA of less than 3 ng/ml – below the current referral criteria for standard transrectal biopsy – despite two thirds being positive by MRI.
Although it is early days, and despite the current lack of feasibility, it is encouraging that this could lead to an MRI-led approach to prostate cancer screening in a larger population. Research is now needed to assess whether an MRI-led screening programme could reduce biopsy rates, over-diagnosis and the associated over-treatment, as well as potentially lower prostate cancer mortality rates following traditional screening methods.
New technologies will be instrumental in this potential development, from improved MRI scanners and embedded clinical decision support to AI-enabled tumour detection algorithms capable of predicting tumour grade and automatically triaging for subsequent biopsies. However, the value of novel, next generation imaging approaches only comes when it is shown to help maximise treatment benefits, minimise under-treatment, and reduce or prevent over-treatment, while tempering both toxicity and costs. This more holistic approach is likely to lead to a closer working relationship between radiology and nuclear medicine departments in future, with convergence of the disciplines to promote integrated care. It could also go some way to alleviating the declining numbers of radiology and nuclear medicine residents entering the profession.
The GE HealthCare Oncology Symposium at ECR 2024 is available to view here.
References
- Hashim, UA et al. 2017. Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. The Lancet, 389(10071): 815-822. https://doi.org/10.1016/S0140-6736(16)32401-1
- Eklund, M et al. 2021. MRI-Targeted or Standard Biopsy in Prostate Cancer Screening. N Engl J Med, 385:908-920. https://www.nejm.org/doi/full/10.1056/NEJMoa2100852
- Moore CM, Frangou E, McCartan N on behalf of the Re-Imagine Study group, et al. 2023. Prevalence of MRI lesions in men responding to a GP-led invitation for a prostate health check: a prospective cohort study. BMJ Oncology, 2:e000057. https://bmjoncology.bmj.com/content/2/1/e000057
