The spread of cancer to the bones (called bone metastases) is one of the most frequent causes of severe pain in people with cancer. While drugs, radiation therapy and surgery sometimes help reduce the pain, a common technology may offer a new approach. It’s called MRI-guided focused ultrasound, used by a device named ExAblate.
Fox Chase Cancer Center physicians are taking part in an international study to see if MRI-guided focused ultrasound can safely and effectively reduce the pain associated with bone metastases when other accepted pain treatments such as radiation therapy don’t help. Fox Chase is the only hospital in the tri-state area studying the technology for this use.
More Powerful Ultrasound
“The ultrasound technique we’re studying is much more powerful and intense than the ultrasound most people are familiar with, such as that used to see structures in the abdomen,” explains Andre Konski, MD, MBA, MA, FACR. One of the lead investigators for the pain study, Konski is director of clinical research for radiation oncology at Fox Chase.
ExAblate MRI-guided ultrasound works by focusing the ultrasound to heat a small spot, much like a magnifying glass can focus light on a target. Unlike light, ultrasound passes through the skin into the body to a spot your doctor wants to destroy, such as a spot in a tumor.
The ultrasound device, made by InSightec Ltd., has been found safe and effective for treating noncancerous fibroid tumors in the uterus. The Food and Drug Administration approved ExAblate MRI-guided focused ultrasound for this use in 2004. The company’s efficacy and safety results in feasibility studies led the FDA to give its permission to investigate ExAblate to treat pain caused by bone metastases.
Guided by MRI
In the current study to treat patients with pain caused by bone metastasis, doctors use MRI (magnetic resonance imaging) to guide them to the area in the bone where the cancer has spread. They then deliver ultrasound to the area, causing extreme heating to destroy nerves that supply sensation-such as pain-to the bone.
The MRI allows the physician to monitor and continuously adjust the treatment in real time. Patients receive conscious sedation to alleviate pain and minimize motion.
Comparing Two Treatment Groups
“We’re optimistic about this approach to treating the pain caused by bone metastasis, but only after the completion of the clinical trial will we know if the technology is useful,” Konski added.
Volunteers for this clinical trial will be randomly assigned to one of two groups. For the first three weeks in the study, one group will receive the treatment and the other group won’t.
After three weeks, the second group of patients will also receive active treatment. Patients in either group will not know if they are receiving active treatment so that its effectiveness can be measured accurately and objectively.
Further information and other locations where the clinical trial is being conducted can be found on http://www.mycancerpain.org/.
Fox Chase Cancer Center