Researchers at the London Health Sciences Centre Research Institute (LHSCRI) have initiated a groundbreaking Phase II clinical trial investigating internal radiation therapy for renal cell carcinoma (RCC), the most common form of kidney cancer. The innovative approach utilizes TheraSphere™ Glass Microspheres containing radioactive Yttrium-90 (Y-90) delivered directly into blood vessels feeding cancerous tumors.
Addressing Critical Treatment Gaps
Kidney cancer affects approximately 9,000 Canadians annually, according to the Canadian Cancer Society. While surgical removal remains the primary treatment for localized disease, many patients cannot undergo surgery due to advanced age, cardiovascular conditions, poor lung function, or history of blood clotting disorders.
"Kidney cancer, if it hasn't spread to other areas of the body, can be addressed surgically by removing some or all of the organ," explains Dr. Derek Cool, Associate Scientist at LHSCRI and Interventional Radiologist at London Health Sciences Centre. "However, not all patients are candidates for surgery due to advanced age or health conditions like heart issues, poor lung function, or a history of major blood clotting. This type of cancer is resistant to chemotherapy and standard radiation."
Revolutionary Internal Radiation Approach
The trial employs a transcatheter approach where Y-90-laden microspheres are delivered directly into the renal artery feeding the tumor. Unlike external radiation therapy that irradiates tissues from outside the body, this method targets cancer cells from within the tumor's blood supply.
TheraSphere™ Glass Microspheres, manufactured by Boston Scientific, are composed of inert glass and encapsulate Y-90, a beta-emitting radioisotope with a 64-hour half-life. The microspheres lodge in the microvasculature of hypervascular tumors, emitting localized radiation at intensities significantly higher than external radiation can safely deliver.
"We expect these beads can deliver 10 times the amount of radiation when compared to external radiation," states Dr. Cool. "By targeting the therapy directly in the tumour, we think we can avoid damage to surrounding organs while also delivering an incredibly strong dose of radiation with a higher potential of destroying cancer cells."
Preserving Kidney Function
The precision of this approach is particularly crucial given the kidneys' essential role in filtering toxins from blood and maintaining electrolyte balance. The targeted delivery system aims to maximize tumoricidal effects while sparing healthy renal parenchyma, potentially preventing renal insufficiency or dialysis dependence.
"Kidneys are essential for survival as they filter toxins from the blood. Preserving normal function is important to avoid kidney failure and the need for dialysis," emphasizes Dr. Cool.
Trial Design and Patient Selection
The study will enroll up to 16 patients from the Verspeeten Family Cancer Centre at LHSC. Eligible participants include those with localized RCC who are deemed unsuitable for surgical resection. Patients will undergo catheter-based retrograde renal artery infusion of TheraSphere™ microspheres, followed by comprehensive monitoring to evaluate tumor response.
The investigative team will analyze treatment impact on tumor volume reduction, progression-free survival, and overall patient tolerance. Success in this pilot study could lead to expansion into a larger multicentre Phase II trial to enhance statistical power and consolidate efficacy data.
Building on Established Success
This therapeutic approach builds on the established efficacy of TheraSphere™ microspheres in hepatic malignancies, particularly hepatocellular carcinoma. The technology represents a proven standard of care for liver cancer treatment and is now being explored for other cancer types.
"Our team at LHSCRI is focused on finding innovative treatments that improve patient outcomes," notes Dr. Cool. "As we look ahead, we hope that this work can not only offer a new treatment option but also enhance the standard of care for patients with kidney cancer."
The study is funded by Boston Scientific Corporation, highlighting the importance of industry-academic partnerships in advancing medical research. The trial exemplifies LHSCRI's commitment to translational research that directly benefits patients by integrating advanced radiologic techniques with molecular oncology.
