To Your Health: Advanced radiation technologies improve accuracy, results
BY FRANK GODLEWSKI Chief medical physicist/Franciscan St. James Health Comprehensive Cancer Institute May 27, 2014 9:24AM
Frank Godlewski | Supplied photo
Updated: June 29, 2014 6:09AM
Stereotactic radiosurgery (SRS), stereotactic radiotherapy (SRT) and stereotactic body radiotherapy (SBRT) offer alternatives to surgery or standard radiation therapy.
These techniques rely on three-dimensional imaging and advanced localization techniques to precisely target tumors and deliver a much higher dosage of radiation than standard treatments.
For patients who are candidates for these therapies, the benefits can be significant. These include fewer treatments, fewer side effects, and the noninvasive nature of these procedures. In some cases, higher cure rates are achieved.
This technology has not replaced conventional radiation therapy, and not everyone is a candidate. Many factors, such as patient suitability, type of cancer and tumor size are taken into consideration before recommending one type of treatment over another.
SRS and SRT usually are used in place of surgery to treat tumors and other abnormalities in the brain. SRS is delivered in a single treatment. When “fractionating,” or spreading out, the treatments is required, the treatment is delivered in three to five sessions and is known as SRT.
SBRT refers to the use of this technology in the body. Some common applications may include small tumors of the lung and growths in the spine. Some of the most dramatic results can be seen in spine patients. A wheelchair-bound patient may become capable of moving on his or her own (with precautionary measures) after just two or three treatments. It is impressive to see results so quickly.
Treating small lung nodules with the high dose of radiation afforded by SBRT can frequently control the tumor, and most of the time, turn it into scar tissue. Often during follow-up after the therapy has been completed, patients’ test results will come back negative.
How it works
During planning, scans such as CT, MRI and PET/CT are used to identify the exact target. This information is used to develop a treatment plan that involves coordinating exactly how the beams of high-dose radiation will converge on the tumor or abnormality. Patient positioning is carefully mapped out.
At the actual time of treatment, the linear accelerator performs a cone beam CT scan. This enables the treatment team to essentially match the patient’s position within a millimeter to the area they are trying to treat with radiation.
During treatment, as beams of radiation converge on the target, the surgical team simultaneously receives real-time information on any movement.
Patients are immobilized during these procedures and cooperate as part of the treatment team. Different types of immobilization are used, depending upon the patient and the procedure.
Procedures involving the brain employ either a hard frame “halo” or a moldable plastic mask. A foot-to-head body fixation device secures the patient and helps restrict breathing motion during SBRT.
While it can still be a shock to receive a diagnosis of cancer, many more options exist today than 20 or even 10 years ago. Local residents should be encouraged that these advanced therapies are available at institutions right here in the south suburbs, such as Franciscan St. James Health.
Frank Godlewski, a board-certified radiation oncology physicist, is chief medical physicist and radiation safety officer at the Franciscan St. James Health Comprehensive Cancer Institute. St. James Health is a member of the Southland Health Alliance.