(UroToday.com) The 2024 American Urological Association (AUA) annual meeting held in San Antonio, TX was host to the Society of Urologic Oncology (SUO) session Dr. Joseph Shirk delved into imaging modalities for active surveillance in renal cell carcinoma (RCC).
Dr. Shirk began by highlighting that according to AUA guidelines, for patients with a solid renal mass <2cm or those that are complex but predominantly cystic, clinicians may elect active surveillance (AS) with the potential for delayed intervention for initial management. Clinicians should consider biopsy of the renal mass and repeat cross-sectional imaging should be obtained approximately 3-6 months after baseline to assess for interval growth. Thereafter, periodic imaging surveillance can be based on growth rate and shared decision-making with patients. The main questions he aimed to address in his talk were:
- Are there better imaging modalities than CT/MRI to risk-stratify tumors?
- Are there adjunctive technologies that surgeons can use with CT/MRI?
Firstly, Dr. Shirk focused on improved imaging modalities other than CT or MRI. He started discussing contrast-enhanced ultrasound (CEUS), an enhanced modality of ultrasound imaging using intravenously administered "microbubbles," which are liquid suspensions of highly echogenic gas-filled microspheres that enhance the reflection of ultrasound waves. The advantages of CEUS include that it does not deliver any ionizing radiation, the microbubbles are not renally metabolized, and patients with claustrophobia can easily tolerate it. He showed examples of how CEUS can easily identify and be used for the follow-up of small renal masses in active surveillance. He presented examples of clear cell renal cell carcinoma appearance on CEUS, with images displayed below:
He proceeded to discuss advanced imaging techniques used with CT and MRI, including Legacy 3D planning, which is a tool for radiologists to improve their reporting but not very useful for surgeons, as it is mainly limited to measurements and volumetrics. Dr. Shirk then delved into newer platforms such as Ceevra, a digital health company that generates AI-driven, patient-specific 3D digital images from standard CT scans and MRIs to aid radiologists and surgeons in surgical planning, ablative therapy decision-making, and follow-up. He also briefly mentioned two other artificial intelligence/machine learning systems: Reveal and Intuitive Iris, noting that all these tools if used for active surveillance of small renal masses could potentially assist in volumetric analysis and improve delineation of margins and anatomical structures.
In closing his presentation, Dr. Shirk concluded:
- Cross sectional imaging (CT and MRI) is still the gold standard for active surveillance
- Other modalities (CEUS) may have value in certain patient cohorts for surveillance.
- Advanced imaging adjuncts to cross sectional imaging may also have a utility (AI/ML) is there to help us.
Presented by: Joseph Shirk MD, Chief of Urology at the Greater Los Angeles VA Health System and Assistant Professor of Urology at the David Geffen School of Medicine at UCLA
Written by: Julian Chavarriaga, MD – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @chavarriagaj on Twitter during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, Fri, May 3 – Mon, May 6, 2024.