Non-Invasive Imaging Technique Accurately Detects Aggressive Kidney Cancer

By MedImaging International staff writers
Posted on 04 Oct 2024

Image: A kidney showing positive [89Zr]Zr-girentuximab PET and histologically confirmed clear-cell renal cell carcinoma (Photo courtesy of Dr. Brian Shuch/UCLA Health)

Kidney cancers, known as renal cell carcinomas, account for 90% of solid kidney tumors, with over 81,000 new cases diagnosed annually in the United States. Among the various types, clear-cell renal cell carcinoma is the most common and lethal, responsible for 75% of cases and 90% of kidney cancer deaths. Early detection is crucial, as survival rates significantly drop if the cancer spreads. When diagnosed early, more than 90% of patients survive for at least five years. However, traditional imaging techniques like CT and MRI often struggle to distinguish between benign and malignant tumors, leading to either unnecessary surgeries or delayed treatments. A new study has introduced a non-invasive imaging technique that can accurately detect clear-cell renal cell carcinoma, potentially reducing unnecessary surgeries and ensuring timely, appropriate treatment. The findings, published in The Lancet Oncology, could revolutionize the diagnosis and management of kidney cancer.

In the study led by investigators from the UCLA Health Jonsson Comprehensive Cancer Center (Los Angeles, CA, USA), the research team tested a non-invasive method that uses a monoclonal antibody drug called 89Zr-TLX250, which targets the protein CA9, commonly found in clear-cell renal cell carcinoma. In the phase 3 ZIRCON trial, 332 patients with suspected kidney lesions from 36 hospitals across nine countries participated, with UCLA leading the global recruitment effort. The study's average participant age was 61, with 71% male and 29% female. Patients received injections of 89Zr-TLX250, which binds to the CA9 protein in kidney masses, allowing detection through PET-CT scans. CA9 is expressed in up to 95% of clear-cell kidney cancers, with minimal presence in normal tissue. Days after the injection, PET-CT scans revealed whether the protein was present, helping doctors assess the likelihood of the mass being cancerous based on the attachment of the drug to cancer cells.

The new imaging technique showed high accuracy in identifying cancer, with 85.5% sensitivity and 87.0% specificity, while minimizing false positives. It proved particularly effective in detecting small renal masses (under 2 cm), increasingly found due to frequent abdominal imaging. Additionally, the procedure was safe, with no major side effects from using 89Zr-TLX250. Researchers now plan to investigate whether 89Zr-TLX250 PET-CT imaging can detect distant metastasis in high-risk patients following nephrectomy. This could help guide treatment decisions after surgery, either intensifying adjuvant therapy if cancer is present or sparing patients from unnecessary treatment if not.

“The implications of this research are vast,” said Dr. Brian Shuch, director of the Kidney Cancer Program and the Alvin & Carrie Meinhardt Endowed Chair in Kidney Cancer Research at UCLA, and lead author of the study. “If adopted widely, 89Zr-TLX250 PET-CT imaging could become a new standard in kidney cancer diagnostics, like how PET-CT imaging has revolutionized prostate cancer management. It could also aid in the detection of other types of kidney cancers and help monitor patients at high risk of metastasis.”