Most of us are familiar with ultrasound when used as a diagnostic imaging test. Also known as sonography, ultrasound is a non-invasive procedure that uses high frequency sound waves to create a picture of structures inside the body. This enables your physician to evaluate many of your body’s internal organs and to identify problems and abnormalities.
More recently, ultrasound has been used as a treatment therapy for specific cancer types. Highly concentrated, or focused, ultrasound waves work to destroy tumor cells with no need for surgery or anesthesia. Currently, focused ultrasound is approved for only a limited number of applications including prostate cancer, uterine myoma and bone metastases. This is due to challenges in targeting organs that move when the patient breathes.
Now scientists at the Fraunhofer Institute for Medical Image Computing MEVIS in Bremen, Germany are working on the TRANS-FUSIMO EU, a focused ultrasound therapy concept that can accurately track liver movement to deliver cancer-fighting ultrasound waves. During treatment sessions, patients lie in an MRI scanner while the machine records the organ’s position every one-tenth of a second. In addition, the scanner monitors liver temperature and ensures target areas are effectively heated.
Treatment sessions begin with a transducer containing more than 1000 ultrasound transmitters being placed on the abdomen. Each of the waves emitted from the individual transmitters are directed to come together delivering a combined dosage precisely at the tumor site. Rather than relying on real time monitoring that is accurate only to one-tenth of a second timing, delivery reliability is enhanced by a unique, real time software program developed by the scientific team.
The program is designed to anticipate organ movement and is capable of calculating the next position of the treatment region, enabling the ultrasound beam to be directed to the precise location, in spite of movement shifts caused by breathing. Certain elements in the ultrasound transducer are deactivated to protect the ribs that lie directly in front of the liver.
Now that the technical development phase has been completed, patient testing of the TRANS-FUSIMO is scheduled to begin in 2018. Positive test results could advance the possibility of using focused ultrasound to treat cancer in other organs that experience movement with breathing.
Patients who have undergone focused ultrasound for approved cancers report very few side effects. When side effects are present, they are typically mild and limited to treatment site discomfort or soreness lasting 3 to 4 days.
This and other emerging treatments offer an encouraging glimpse into the future of cancer treatment.