Elekta Extend program technology offers certain patients an inroad to Gamma Knife Perfexion radiosurgery for challenging targets in the brain, skull base and other head/ neck areas.Afghanistan — Monday, February 22, 2010
Just one year after it began clinical use of Elekta’s Leksell Gamma Knife® Perfexion™ radiosurgery system, Barnes-Jewish Hospital (St. Louis, Mo., USA) is poised to offer the benefits of Gamma Knife® surgery to several new patient groups. With Elekta’s Extend™ program for Gamma Knife Perfexion, Barnes-Jewish doctors will now be able to treat–over two to five radiosurgery sessions–patients with larger tumors or lesions close to critical structures located in the brain, skull base and in other regions in the head and neck.
Extend is a program that allows clinicians to non-invasively fix or immobilize the patient’s head, making repeatable or “hypofractionated” Gamma Knife surgery practical for these cases.
Barnes-Jewish Hospital is the second U.S. center to offer these benefits with the new Elekta technology.
“Extend represents additional growth in our capability and flexibility to meet patient needs with specialized radiation therapy,” says Joseph R. Simpson, M.D., Ph.D., co-director of Barnes-Jewish Hospital’s Gamma Knife of St. Louis .
While single fraction Gamma Knife surgery excels in treating small malignant and benign lesions and those in less critically located regions in the head, Extend captures treatment indications in which a hypofractionated approach has the potential for a better clinical result. For example, in cases in which a small tumor abuts a critical structure, physicians can use Extend to provide a greater anti-tumor effect over repeated treatment fractions (i.e., treatment sessions).
Another promising use of Extend at Barnes-Jewish Hospital will be glomus jugulare tumors, according to Dr. Simpson. Glomus jugulare tumors grow along the jugular vein, eroding the bones of the skull, where nerves are located. Often these tumors extend too far below the skull base to be reached with a frame-based Gamma Knife approach.
“We typically use linear accelerator-based radiotherapy to treat these tumors,” he says. “However, the disadvantage of that technique for glomus jugulare lesions is that they require more fractions, which means more time and greater potential for side effects.”
In evaluating their decision to acquire Extend, the radiation oncology and neurosurgery departments also provided information on the solution to ENT (ear-nose-throat) physicians in the otolaryngology department to determine their interest. These clinicians could refer certain cases for hypofractionated radiosurgery with Extend, including patients with nasopharygeal carcinoma, paranasal sinus tumors and extensive skull base tumors, he says.
“The ENT doctors are interested in being more ‘focal’ or precise with radiation therapy, and hypofractionated radiosurgery certainly offers that potential, with the likelihood of fewer side effects,” Dr. Simpson observes. “In fact, an ENT doctor was one of two physicians here who recently went for Leksell Gamma Knife training.”
The key components of Extend are patient-friendly fixation devices, such as a vacuum assisted bite block and head support with vacuum pillow. Accurate repeat fixation is ensured with a one-time use of a CT box to obtain precise stereotactic reference points, followed by repeat checks using reposition check instruments for each Gamma Knife session.
Elekta will deliver Extend to Barnes-Jewish Hospital in early April. Dr. Simpson anticipates treating their first patients soon after.
Barnes-Jewish acquired Leksell Gamma Knife in 1998. In 2008, it was replaced with Leksell Gamma Knife Perfexion, the most advanced radiosurgery solution available. Barnes-Jewish Hospital has performed Gamma Knife surgery on over 2,000 patients and metastases represent half of the medical center’s approximately 220 Gamma Knife cases annually.