A type of therapy designed to treat cancers not easily addressed with surgery or
conventional radiation is now being offered at Samaritan Regional Cancer Center in Corvallis.
Stereotactic Body Radiation Therapy delivers a high dose of radiation directly to a tumor volume — the portion of an organ or skin that includes both the tumor and area of invasion. Because of its accuracy, this form of therapy can be done in fewer treatments than standard therapy and with minimal effect on nearby organs.
According to Elizabeth Shiner, MSc, DABR, chief medical physicist with Samaritan Regional Cancer Center, the technology, among other services, puts treatment available locally on par with other cancer centers.
“We offer excellent radiation therapy to patients throughout the region,” said Shiner. “Not all centers that use this treatment have the 4-D CT scanning technology, which is really instrumental in helping us plan for the movement of the mass,” she said. “I would stack Samaritan Regional Cancer Center against any cancer facility in Oregon, or even the country.”
According to Ken Nitta, MD, a radiation oncologist at the center, Stereotactic Body Radiation Therapy can be used in patients with cancer of the lung, spine, and brain. Treatment for cancer in the liver, pancreas and prostate is also performed to a limited extent at some academic centers. “This therapy is also a good option for patients who have small lung tumors, and who are not surgical candidates due to other health problems.”
Some key features of the therapy include:
Using a 4-D CT scanner, a virtual motion picture of the patient’s CT scan is created, which allows doctors to precisely track the motion of the tumor and surrounding organs during the entire breathing cycle.
With image fusion and intensity modulated treatment planning, providers are able to take multiple types of diagnostic images (PET, CT and MRI) and fuse the images together, which gives the radiation oncologist the ability to very accurately delineate both tumor volumes and critical structures. This innovative treatment planning allows providers to create a computerized virtual patient, mapping multiple beams from multiple angles to target the tumor volume and avoid critical structures within the patient.
A special body mold and frame device is used to ensure accurate patient positioning throughout the treatment. An abdominal compression device can also be applied to reduce tumor motion that occurs with breathing.
Cone-Beam CT imaging
Cone-Beam CT imaging, also known as three-dimensional image-guided radiation therapy (IGRT), allows providers to do a special type of CT scan during treatment. This feature also allows providers to monitor any changes in the size, shape and location of the tumor during the treatment, with greater accuracy than ever before.
With Stereotactic Body Radiation Therapy, three to five treatments are delivered over the course of one to two weeks. Side effects and their severity depend on the total dose of radiation received, the amount of tissue requiring radiation and the part of the body being treated. The most common early side effect of radiation therapy is fatigue. For lung cancer patients, side effects may also include shortness of breath, coughing and transient bone pain.
To date, the center has treated 10 lung cancer patients with Stereotactic Body Radiation Therapy.