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The prevalence of primary liver cancer is increasing worldwide, including due to an increase in the number of hepatitis C infections and other chronic liver diseases. Liver cancer is very difficult to treat – 750,000 people die from it every year worldwide, making it the second most important type of cancer after lung cancer. Modern methods of treatment include targeted radiation therapy using radiating glass granules. A new study shows that this treatment can be enhanced by introducing lipid microbubbles into the liver and collapsing them with ultrasound. The results of the first pilot clinical trial of this treatment tactic were published in the journal Radiology.
The combination of glass granules with microbubbles has already shown its effectiveness in preclinical studies using animal models of bladder, prostate and breast cancer.
The aim of the new study is to prove the safety and effectiveness of the approach for people with liver cancer.
Approximately 15-25% of patients with late-stage liver cancer recommend transarterial radioembolization (TARE), in which radioactive glass granules are injected into the blood vessels of the liver, irradiating the tumor and destroying it. However, the degree of penetration of radiation into the liver tissue is limited, and the reaction of the tumor strongly depends on the distance to the radioactive granules. Combining TARE with microbubbles reduces the dose of radiation needed to destroy blood vessels in the tumor and increases the effectiveness of treatment.
The microbubbles themselves are commercially available in the form of ultrasound contrast agents, the procedure for introducing microbubbles into a tumor is similar to the methods used to access blood vessels.
When an ultrasonic wave acts on the microbubbles, they begin to vibrate, and if the wave is strong enough, they burst. The pure energy of these tiny explosions causes physical and chemical damage to the tumor's blood vessels, making them more sensitive to radiation. By directing ultrasound precisely to the place where the tumor is located, researchers can explode the bubbles exactly where the glass granules are located and achieve clearly localized sensitization.
The pilot study included 28 patients who were randomly assigned to two treatment groups: only radioembolization (TARE) or radioembolization plus destruction of microbubbles under the influence of ultrasound (TARE + UTMD). The research team first evaluated the safety profile of the microbubbles. No changes in vital functions, such as body temperature, blood pressure and heart rate, were observed in patients receiving UTMD. It is important to note that UTMD did not affect liver function, and there were no additional side effects with combined treatment.
The researchers studied 10 cases in the TARE-only group and 15 cases in the TARE + UTMD group and evaluated the tumor response to each treatment. In the TARE + UTMD group, 93% of patients showed a partial to complete response, while in the TARE group, only 50% showed a response to treatment.
The team also found that patients receiving combination therapy were more likely to receive a liver transplant, giving a better prognosis of survival for patients with cirrhosis and liver cancer. These patients also lived longer and needed fewer repeated courses of therapy compared to patients who received only TARE.
The results suggest that the new treatment may be effective in metastatic liver tumors, as well as other types of primary cancer. In addition, the bubbles themselves can be designed to deliver and release chemotherapeutic drugs or reactive oxygen species.
The group is currently recruiting patients to conduct a larger clinical trial.
The article by J.R.Eisenbrey et al. US-triggered Microbubble Destruction for Augmenting Hepatocellular Carcinoma Response to Transarterial Radioembolization: A Randomized Pilot Clinical Trial is published in the journal Radiology.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru Based on Thomas Jefferson University: A First-in-Human Clinical Trial Shows Microbubbles May Improve The Effectiveness of Radiation Therapy in Patients with Liver Cancer.