New Interventional Platform Reduces Radiation Exposure for Patients and Clinicians

A new imaging platform allows for significant X-ray radiation dose reduction without compromising image quality in patients undergoing intra-arterial therapy (IAT) for liver cancer, according to research presented at RSNA 2014.

In hepatic IAT, treatment is delivered under fluoroscopic guidance directly to liver tumors through the blood vessels that feed them. Local delivery of chemotherapeutic drugs allows for increased drug dose while achieving reduced side effects compared to intravenous, systemic delivery; however, the IAT procedure exposes both patients and interventional radiology staff to ionizing radiation. Increased use of hepatic IAT during the last decade has raised concerns over radiation exposure, especially given the fact that patients undergo repeat treatments.

Ruediger E. Schernthaner, M.D., from the Johns Hopkins Hospital in Baltimore, and colleagues investigated a new C-arm imaging platform that offers optimized parameters for IAT-associated image acquisitions like fluoroscopy, digital subtraction angiography (DSA) and cone beam computed tomography (CBCT).

Daily Bulletin coverage of RSNA 2014 is available at RSNA.org/Bulletin

The researchers tested the platform—the AlluraClarity from Philips Healthcare of Best, The Netherlands—on 52 patients and compared radiation exposure and image quality with results from 26 other patients who had undergone similar procedures on an older system. Radiation exposure, including air kerma (AK), the radiation exposure in free air before reaching the body, and dose area product (DAP), the absorbed radiation dose multiplied by the area irradiated, was recorded throughout the procedure.

The new system resulted in an exposure reduction in total AK and DAP of 58 percent and 60 percent, respectively, compared to the old platform. DAP for fluoroscopy, DSA and CBCT decreased by up to 66 percent, 79 percent and 14 percent, respectively. During the procedures, no relevant problems due to image quality were reported. Likewise, the blinded evaluation of image quality revealed no differences between the new and the old imaging platforms. Both patient cohorts showed no difference with regard to body mass index or fluoroscopy time.

“The main finding is that the radiation exposure for patients undergoing IAT can be significantly lowered, which is especially important for patients undergoing several procedures,” said Dr. Schernthaner. “In contrast to diagnostic imaging, the decreased radiation exposure not only affects the patient, but also the staff who are in the room performing the procedure because their lifetime cumulative dose can be lowered.”

Applications Possible in Gynecologic, Pediatric Imaging

Dr. Schernthaner predicted that the new platform would have applications beyond IAT of the liver. “We are currently investigating the potential of this new platform for women with uterine fibroids treated with uterine artery embolization,” he said. “Some of these women are at a child-bearing age, where radiation exposure is of even greater concern. And the most important patient population with regards to radiation exposure are pediatric patients, who are the most sensitive group to radiation exposure, especially when considering the cumulative lifetime risks associated with X-ray exposure. This new platform is an essential step to minimizing this risk.”

Web Extras

Ruediger E. Schernthaner, M.D., MingDe Lin, Ph.D., and Jean-Francois H. Geschwind, M.D., discuss their RSNA 2014 research:

• Dr. Schernthaner addresses the risks associated with IAT.
• Dr. Geschwind discusses how the new IAT system lowers those risks.
• Dr. Lin explains the how the radiation reduction benefits clinicians as well as patients.
• Dr. Schernthaner discusses how this platform might be extended beyond those with liver cancer.
• Dr. Geschwind discusses the potential of the IAT system for widespread use.