Advanced Treatment Techniques
RapidArc® radiotherapy technology is a major advance from Varian Medical Systems that improves dose conformity while significantly shortening treatment times. RapidArc delivers treatments two to eight times faster than our fastest dynamic treatments today and increases precision - a winning combination that enables physicians to improve the standard of care and treat more patients. Implemented in July 2011, we have already seen a drastic decrease in the amount of time required for each patient's daily treatment. For more information click here to watch a short informational video.
Intensity Modulated Radiation Therapy
Intensity modulated radiation therapy (IMRT) is a fairly new, complex technique used to deliver a high dose of radiation to a tumor while avoiding nearby healthy and/or critical structures. Some critical structures, like the spinal cord for example, can only tolerate a certain amount of radiation before causing permanent harm. Using IMRT allows for dose escalation to the tumor, while decreasing the possibilities of radiation side effects. Intense treatment planning is done by the Radiation Oncologist and treatment planning team. IMRT is delivered daily Monday through Friday typically for 5-7 weeks, depending on the treatment area. Memorial began IMRT treatment technique in 2002.
Image Guided Radiation Therapy
Some organs, such as the prostate, move due to normal daily volume changes in the bladder and rectum. For precise targeting of the prostate, gold markers can be placed into the prostate for imaging immediately before daily radiation begins. These gold markers show up using the Trilogy's On-Board Imager (OBI) and allow the therapist to quickly make any positioning corrections before treatment is started. The On-Board Imager can also be used when no gold markers are present. Bony anatomy can be used for target alignment immediately before treatment begins.
The Trilogy's Cone Beam CT is also used to aid in precise treatment delivery. The Cone Beam CT data shows "real-time" tumor positioning in a three-dimensional view. Anatomy or the tumor itself can be visualized and used for alignment. Once the alignment is completed, the therapist can make any corrections before treatment begins.
Beginning in 2006, Memorial began using Respiratory Gating technology for treatment planning and treatment delivery. Some tumors in the lung or abdomen move during a patient's normal respiration process. By planning the treatments using Respiratory Gating, the Radiation Oncologist can take this motion into account. If tumor motion is excessive, Respiratory Gating is used during treatment delivery. During treatment delivery, the Trilogy "watches" the patient's breathing movement, starting and stopping the beam when the tumor moves out of field.
Recently, Memorial Radiation Oncology Center started using this technique in the treatment of left-sided breast cancer patients. Heart dose has long been a top consideration for left-side breast treatments, due to the tangential projectory of the beam. By having the patient take a deep breath and hold during radiation, the lungs actually move the radiation field away from the heart. Radiation dose to the heart is dramatically reduced with this method. Trilogy's Gating cameras and technology is used to ensure proper breath hold amounts are used for daily reproduction of breath holds.