Tasing Brain Tumors
Treating glioblastomas with electrical currents to prolong survival
BY MATTHEW GRESETH
Of all brain tumors, glioblastoma has one of the worst prognoses. After surgery and chemotherapy, patients survive on average around 15 months; approximately 30 percent are still alive at two years. “Glioblastoma is still thought of as an incurable disease and, for that reason, additions to the standard of care regimen are necessary and beneficial,” says Scott M. Lindhorst, M.D., a neuro-oncologist at MUSC Hollings Cancer Center.
News that a novel noninvasive therapy—tumor-treating fields (TTFields)—extended survival by five months in recurrent glioblastoma generated considerable interest in 2011, and it soon became part of the standard of care for that disease. Last year, TTFields were approved by the FDA for use in patients with newly diagnosed glioblastoma as well.
TTFields are low-intensity, alternating electric fields that prevent proliferation of cancer cells by disrupting mitosis. Patients wear a battery-operated cap containing an array of ceramic discs, which deliver the fields to targeted regions of the brain. The cap and its placement are customized to the patient’s tumor, based on their MRI brain imaging. The longer the patient is able to wear the cap throughout the day, the better the outcomes seen. Although the therapy requires a lifestyle adjustment, it is well tolerated by most motivated patients.
“The next step is now to determine whether we can expand the use of this device to other tumor types, and that’s where the research we’re doing is heading,” says neuro-oncologist David M. Cachia, M.D. Cachia and Lindhorst are beginning clinical trials in patients who have lung cancer that has metastasized to the brain and are collaborating with investigators at other institutions to monitor outcomes with TTFields in patients with lower-grade gliomas. While TTFields do not currently cure brain tumors, they do significantly prolong survival of patients with these notoriously difficult-to-treat tumors.
A Perfect Fit
Image-guided shoulder arthroplasty enables surgeons to plan their surgeries virtually and then be guided by real-time feedback during the operation, resulting in more precise placement of components and improving both range of motion and longevity of the shoulder replacement.
“The beauty of this is we can now be a lot more precise with the placement of the component parts,” says MUSC Health orthopaedic surgeon Josef K. Eichinger, M.D., who was among the first surgeons in the Southeast to perform shoulder replacements using the new technology (ExactechGPS shoulder application, Exachtech; Gainesville, FL). MUSC Health orthopaedic surgeons Richard J. Friedman, M.D., and Shane K. Woolf, M.D., also use the technology for shoulder replacement surgeries.
Shoulder replacement components include a metal ball that takes the place of the humeral head, a rod that is inserted into the humeral shaft to hold the ball in place and a smooth plastic apparatus fitted onto the surface of the glenoid cavity or “socket” that ensures a smooth fit for the metal ball. Inaccurate fits can decrease the longevity of the replacement and limit the joint’s range of motion. Unfortunately, visualization of the scapula is difficult through the socket. The lack of visualization is particularly challenging in patients who require bone grafts or augmentation before placement of the components, such as those with arthritis who have unusual wear patterns or those with congenital abnormalities that affect the socket.
The new technology uses a patient’s CT scan to create a 3D reconstruction of his or her shoulder anatomy. The surgeon can then preplan the operation in virtual reality with perfect visualization. On the day of surgery, trackers are placed on designated areas of the shoulder anatomy and on the surgeon’s instruments and registered in the system. A specially designed tablet that can “see” both sets of trackers enables triangulation so that the system knows exactly where the surgeon is cutting. The virtual surgery provides a map for the surgeon to follow, and the system provides real-time visual feedback to guide the surgeon’s decisions.
“With this technology, we can assure more complex patients that we are doing everything we can to ensure accuracy, avoid complications and provide maximum longevity of their shoulder replacement,” says Eichinger. —KIMBERLY MCGHEE