Tiny microbubbles are being used to more effectively treat liver cancer, according to a pilot study described at the 33rd annual Advances in Contrast Ultrasound—Bubble Conference, held Sept. 6-7, in Chicago.

Patients with hepatocellular carcinoma (HCC), the third leading cause of cancer deaths worldwide, were found to benefit from a combination of contrast-enhanced ultrasound (CEUS) and radiation therapy, according to John Eisenbrey, PhD, a researcher at Thomas Jefferson University in Philadelphia.

“These are exciting preliminary findings because hepatocellular carcinoma is the most common form of liver cancer, and microbubbles appear to sensitize the tumor to the radiation therapy,” Eisenbrey says.

For many years, CEUS has used liquid suspensions of tiny gas microbubbles to improve the clarity and reliability of diagnostic ultrasound images of the heart, liver and other organ systems. The Thomas Jefferson study found that these ultrasound contrast agents can also be used to improve the effectiveness of cancer therapy, with the microbubbles playing a role in tumor death.

The study included one set of patients with liver cancer treated with radiation therapy only and a second set of patients who received radiation therapy combined with CEUS. Researchers found that patients receiving a combination of CEUS and radiation saw destruction of the vessels that carry blood to the tumor, with a 25 to 60% increased response to the radiation treatment. “The microbubbles produced a clear therapeutic benefit,” Eisenbrey notes.

“These findings are extremely exciting and appear to be consistent with previous work using the microbubbles to enhance absorption of chemotherapy drugs,” according to Dr. Steven Feinstein, co-president of the International Contrast Ultrasound Society, and a professor of medicine at Rush University Medical Center in Chicago. “Microbubble contrast agents are extremely safe and useful for diagnostic ultrasound imaging, and their new therapeutic uses are very promising,” Feinstein says.