A team of radiation oncologists at the Holy Name Hospital in Teaneck are combining 4D imaging using PET/CT scanners, respiratory gating and IMRT (intensity modulated radiation therapy) to offer extremely precise treatments for patients who experience a high level of tumor motion.
Both GE Healthcare and Varian Medical Systems are providing the imaging and radiotherapy delivery technology to help the clinicians track the motion of tumors within the body and deliver image-guided radiation therapy. The systems have treated 23 patients to date.
"Using these different technologies has enabled us to discover very unexpected movement in some of the tumors," said Jacqueline Brunetti, MD, director of Radiology at Holy Name. "If the patients had been treated conventionally, the tumors would have moved out of the treatment field and we might have under-treated them."
The PET scan captures the metabolic activity of the tumor while the CT scan provides high-resolution images clearly depicting the tumor's location and structure. Together, the two scans can be used to detect and evaluate tumor cell activity as well as locate the site with pinpoint accuracy.
By using these scans as the basis for the treatment plan and incorporating Varian's RPM respiratory gating system and GE's Advantage 4D gating application to track motion within the patient's breathing cycle, treatment accuracy can be significantly enhanced. Holy Name Hospital's patients are treated on Varian Clinac linear accelerators, which can rapidly deliver precisely shaped IMRT treatment beams that focus higher doses on tumors while protecting surrounding healthy tissue. The RPM Respiratory Gating system is one of Varian's tools for delivering Dynamic Targeting image-guided radiation therapy.