Radiation Therapy - Elekta Synergy Linear Accelerator
Radiation therapy is the use of radiation to safely and effectively treat cancer and other diseases. Radiation oncologists may use radiation to cure cancer, to control the growth of the cancer or to relieve symptoms. Sometimes radiation therapy is the only treatment a patient needs. At other times, it is only part of the patient’s treatment plan which may also include surgery and chemotherapy.
Basics
Radiation therapy is the careful use of high-energy radiation to treat cancer. Radiation may be used to cure cancer or to relieve a cancer patient’s pain. The radiation destroys the cancer cells’ ability to reproduce and the body naturally gets rid of these cells. Radiation may be given externally or internally; we will be delivering external beam radiation therapy with a linear accelerator.
How It Works
The linear accelerator accelerates electrons to the wave guide, then allows these electrons to collide with a heavy metal target. High-energy x-rays are scattered from the target. A portion of these x-rays is collected and then shaped to form a beam that matches the patient’s tumor. The beam comes out of the gantry which rotates around the patient. The patient lies on a moveable treatment couch and lasers are used to make sure the patient is in the proper position.
Intensity Modulated Radiation Therapy (IMRT)
Utilzes computer-controlled linear accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor. The radiation dose is designed to conform to the 3-D shape of the tumor by modulating or controlling the intensity of the radiation beam to focus a higher radiation dose on the tumor while minimizing radiation exposure to surrounding normal tissues. Because the ratio of normal tissue dose to tumor dose in reduced to a minimum means a higher and more effective radiation dose can be safely delivered to tumors with fewer side effects.
Image Guided Radiation Therapy (IGRT)
Combines scanning and radiation equipment to provide images of the patient’s organs in the treatment position at the time of treatment, optimizing the accuracy and precision of the treatment. Allows the radiation oncologist to adjust the radiation beam based on the position of the target tumor and critical organs, while the patient is in the treatment position.
Treatment Procedure
Simulation is performed by a radiation therapist and the radiation oncologist on the PET/CT scanner utilizing the CT or PET/CT capability. The patient is placed in his/her treatment position, and small tattoos are given for reference and for reproducibility of the daily treatment.
Data from the simulation is transferred to the treatment planning computer and a dosimetrist along with the radiation oncologist creates a treatment plan that can best destroy the tumor while sparing the normal tissues. Dr. Dave Gannett is our radiation oncology medical director. Other radiation oncologists with The Oregon Clinic will also work at our site.
Medical physicist reviews the treatment plan. The medical physicist is also responsible for making sure the linear accelerator is working properly by taking precise measurements of the radiation beams.
Radiation therapists position the patient on the treatment table daily using their reference tattoos. Patients are usually treated every week day and treatments take 15-45 minutes depending on the type of treatment being delivered. Patients do not feel anything during their treatment.
Safety
During treatment, the patient is in the room by themselves and is monitored at all times by the radiation therapist by closed-circuit television monitors and an intercom system. There is no residual radioactivity in the patient after treatment is given.
- The accelerator sits in a vault with lead and concrete walls so that the high-energy x-rays do not escape.
- The accelerator only gives off radiation when it is actually turned on.
- The accelerator will not turn on if the door is open.
- The accelerator will not turn on until all the correct treatment parameters for each specific patient are in place which is verified utilizing a record and verify system called IMPAC.
New Cancer Center
After much anticipation, the new Pacific Oncology Cancer Center is now open to the public.