External Beam Radiation Therapy
External Beam Radiation Therapy-is one of the most common forms of radiation therapy. This technique involves focusing a "beam" of high-energy radiation, using a linear accelerator, from outside of your body to the cancerous organ and/or tissue within your body. The treatment itself lasts only a few minutes. It is administered over a period of six to eight weeks, typically five days a week.
Recent advances in radiation therapy can more accurately target the tumor with higher doses of radiation, while minimizing damage to healthy tissue. External beam radiation therapy poses no risk of radioactivity to you or others with whom you have contact.
About TrueBeam™ Radiotherapy System High-Precision Radiotherapy Treatment
TrueBeam is changing the way cancer is treated. The new, state-of-the-art radiotherapy technology delivers more flexible cancer treatments with pinpoint accuracy, ease and speed. TrueBeam allows clinicians to tailor patient treatments for their particular type of cancer and most treatments only last a few minutes, instead of half-an-hour for traditional methods. TrueBeam treats cancer anywhere in the body where radiation treatment is indicated, including lung, breast, prostate and head and neck.
Technologies such as motion management and integrated imaging are some of the tools that are required for the delivery of advanced treatments like stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS).
Streamlined imaging and patient positioning tools enable more flexibility to treat clinical cases throughout the body. Having the power to not only treat quickly, but to deliver high, accurate dose rates are hallmarks of the TrueBeam system.
The system continuously monitors tumor movement and helps clinicians deliver radiation only when the tumor is in the right place, while the patient continues natural breathing.
Designed to treat targets using sub millimeter mechanical accuracy of the couch, collimator, and gantry, Varian's TrueBeam dynamically synchronizes imaging, patient positioning, motion management, and treatment delivery and can be used for many forms of radiation therapy modalities.
IMRT, or intensity modulated radiation therapy
Uses 3-D scans of your body to guide the beams of radiation to the tumor from many different angles. At each of these angles, the intensity of the radiation is varied (modulated) and the shape of the beam is changed to match the shape of the tumor. These adjustments enable the prescribed amount of radiation to be delivered to each part of the tumor, while minimizing exposure to the surrounding healthy tissue. Treatments are typically given daily for 10 to 20 minutes over a six to eight week period.
RapidArc, is an advanced form of IMRT that uses special software and an advanced linear accelerator to deliver IMRT treatments up to eight times faster than what was previously possible. Unlike conventional IMRT treatments, RapidArc can deliver the dose to the entire tumor in a single rotation - in less than two minutes.
IGRT, or image-guided radiation therapy
Uses sophisticated computer software to analyze a series of image scans to create a detailed, three-dimensional picture of the target area and surrounding tissue, which enables your team to view the tumor and its position in your body before and during each treatment.
SRS, or stereotactic radiosurgery
SRS is a technique most commonly used for tumors in the brain or spinal column. SRS is typically delivered in a maximum of five sessions using higher doses of radiation with each session. Despite the use of the word "surgery" in its name, SRS does not involve removing the tumor with a surgical blade. Instead, a focused high-intensity beam of radiation is used to target the tumor.
SBRT, or stereotactic body radiation therapy
SBRT is a very similar technique to SRS, but is used for targets outside the brain and the spine. SBRT is most commonly used for targets in the lung, liver, pancreas and kidney, and is typically delivered in a maximum of five sessions.
It is important that you are in the right place during your treatment so the radiation is targeting the correct area of your body. Vision RT tracks the patient's 3D surface in real time, calculates precisely any patient movement in all six degrees of freedom, and monitors any respiratory motion. This optical surface tracking capability ensures a patient is set up in the correct position before radiation therapy and tracks any movement during the treatment via real time feedback.
Respiratory gating is a process for continuously monitoring the movement of tumors during normal breathing. Radiation is only delivered when the tumor is exactly in the right place, and the treatment beam automatically turns off when the tumor moves outside of the target field. This technique is used as part of some radiation therapy treatment plans.
Deep Inspiration Breath Hold Technique
One of the main concerns during radiation therapy, specifically when treating the left breast, is its proximity to the heart, which is also on the left side of the body. Heart tissue can potentially receive some of the radiation dose, possibly causing heart complications. To help physicians reduce the amount of radiation that reaches the heart, some patients receiving radiation therapy for left breast cancers are taught the Deep Inspiration Breath Hold (DIBH) technique. Using DIBH, the heart can be moved away from the radiation beams, minimizing exposure, while ensuring that the breast/chest wall area receives the fully prescribed dose.
The DIBH technique requires the patient to deeply inhale and hold in air in their lungs for about 20 seconds while the radiation is being delivered. Holding in a deep breath pulls the diaphragm and heart down and out of the radiation beam path. The patient can breathe normally between treatment doses.