Radiology faculty are leading an investigation to improve imaging options available to patients who have undergone Selective Internal Radiation Therapy (SIRT), the latest treatment option available at the University of Tennessee Medical Center for those with inoperable hepatic tumors. SIRT is a non-surgical therapy that uses microscopic radioactive spheres, called SIR-Spheres®, to deliver radiation directly to the site of the liver tumor.
The procedure involves injecting billions of microscopic acrylic spheres (microspheres) containing the radioactive isotope Yttrium-90 into the liver tumor through the right or left hepatic artery. The microspheres lodge in the area of the tumor, where the radiation kills and slows the growth of the cancer cells. To optimize this treatment, the location of the microspheres is commonly imaged using a nuclear medicine SPECT scan. However, for technical reasons, SPECT is only capable of providing crude images of the Yttrium-90 isotope.
At the UT Graduate School of Medicine, Anastasia Balius, MD, Assistant Professor of Interventional Radiology, is leading a clinical trial with J. Mark McKinney, MD, Chair of Radiology, and Alexander Pasciak, PhD, Assistant Professor and Medical Physicist, to determine if PET/CT technology, considered the cutting-edge in oncology for its sensitivity to cancer, can be used to improve SIRT treatment by providing imaging which is superior to the traditional SPECT scan. Dr. Balius said, “Patients that come to the University of Tennessee Medical Center for SIRT have the opportunity to participate in exciting new PET/CT research that has the potential to improve SIR-Spheres® delivery and follow-up. We are one of a select few facilities in the nation participating in this type of investigation for advanced liver cancer.”
At the forefront of PET/CT imaging equipment is the Siemens Biograph mCT PET/CT scanner, which the research team utilizes for this clinical trial. It is through an ongoing collaborative research relationship with Siemens, a global leader in medical imaging, that this technology is available at the UT Graduate School of Medicine.
While treatment with SIR-Spheres® is generally not regarded as a cure to liver cancer, it has been shown to shrink liver cancer more than chemotherapy alone.
“SIR-Spheres delivers more radiation targeted directly to tumors and spares more healthy tissue than would be possible using conventional external radiation,” said Dr. J. Mark McKinney, Radiology Chair and Interventional Radiologist at the University of Tennessee Medical Center. “This new capability allows us to treat tumors in the liver regardless of the size or location with a precise, yet high dose of radiation. The treatment has been shown to shrink liver tumors and improve the quality of patients’ lives.”
The University of Tennessee Medical Center is the only site in East Tennessee offering SIR-Spheres® for the treatment of liver cancer. SIR-Spheres® is one of many options among a full array of treatments made available for patients with primary/metastatic liver disease. In addition to SIRT, other procedures to treat liver cancer include: surgery, radiofrequency ablative therapy, chemoembolization and stereotactic radiation therapy.