Researchers at Stanford University have been able to use MR-guided focused ultrasound (MRgFUS) to treat a patient’s cancer pain in her right hip, after failed radiation and placement of orthopedic hardware.
Metal orthopedic implants can hinder the ability to visualize and target a treatment area with MRgFUS. Stanford radiologist Pejman Ghanouni, MD, PhD, and MRI physicist Brian Hargreaves, PhD, are collaborating on a project funded by a National Institutes of Health grant to develop ways of enabling MRI-guided focused ultrasound treatment for patients with metal hardware. They have made advances that allow them to see the tumor and measure the treatment effect and are working on methods to make MR thermometry more reliable.
In May, they performed a successful FUS procedure of a destructive mass in the femur of a woman with metastatic kidney cancer. The patient, named Nancy, has been living with cancer since 2013. She had a rod inserted in her hip, followed by radiation to treat persistent pain. Several months ago, the pain from her cancer had increased to the point that she again needed treatment. A radiograph of her hip showed progressive destruction of the proximal femur from the metastasis. Since re-irradiation has a lower success rate for the treatment of bone metastases than primary radiation therapy, her radiation oncologist was not confident that the tumor would respond to re-irradiation. Her orthopedic surgeon considered a hip replacement, but told Nancy that this would involve a long recovery. She was referred to Dr. Ghanouni to be considered for MR-guided focused ultrasound. Because of the limitations of the other treatment options available, Dr. Ghanouni believed that FUS was reasonable, and could be done safely as a single outpatient procedure with a good chance of success.
“It was a hard decision because I was nervous about being the first patient with hardware to have this done. It took a couple of weeks for me to decide to undergo the focused ultrasound treatment, and during that time the pain kept getting worse,” Nancy explains. “I was asleep during the procedure, and when I woke up I went home and felt fine. I was advised to continue using my wheelchair during the week after the procedure. But I felt so good after three days that I got up and did some laundry,” she confesses. In fact, she went on to become the bocce ball champion in her retirement community after the procedure.
“Bone metastases can be very painful and disabling, and patients who do not have adequate pain relief after radiation and orthopedic stabilization have few options for treatment,” says Dr. Ghanouni. “We are encouraged by our success in this case and will continue our work to explore and expand the boundaries of what is clinically feasible so that MR-guided focused ultrasound can become accepted as a viable treatment option for these patients.”