Lung cancer is the leading cause of cancer death in Kentucky. In the United States, more than 200,000 new cases are diagnosed each year.
If diagnosed early, a common treatment for non-small cell lung cancer is surgery to remove the cancer, often along with an entire lobe of the lung. Surgery requires the patient to be healthy enough to survive the operation and to be able to breathe adequately with less lung tissue.
When surgery is not possible, doctors often turn to radiation therapy. Traditional techniques deliver a relatively small daily dose, five days per week over a period of six to seven weeks.
A newer approach for radiation therapy is called Stereotactic Body Radiation Therapy. SBRT delivers a greater dose per session. Treatment is completed in a handful of sessions rather than 30 or more. SBRT also improves effectiveness while reducing the risks of treatment.
The demand for precision is addressed in various ways. Small seeds called fiducial markers may be placed within the tumor by a pulmonologist. Next, a body mold is custom fit to the patient to minimize body movement, thus ensuring consistency of treatments from one session to the next. Other devices may be used to limit movement from breathing.
The next step is to obtain CT scans with these devices in place. One scan captures the lung tumor’s movement during respiration, creating a short movie of the lungs at work. This information allows the radiation oncologist to make sure that radiation is accurately delivered during the patient’s normal breathing cycle.
Once the scans are complete, the physician and dosimetrist create the treatment plan using specialized computer software. The tumor, as well as organs such as the heart, lungs, spinal cord and windpipe, are carefully delineated.
Using the model, a plan is designed to treat the tumor while avoiding as much of the surrounding structures as possible.
With positioning devices in place, the linear accelerator obtains a CT scan that is overlaid with the plan for final approval by the radiation oncologist. Various tools with the linear accelerator and treatment table allow fine-tuning of the patient’s position for optimal alignment. High-energy X-ray beams from the linear accelerator then treat the tumor.
The Versa HD linear accelerator is a new technology that allows lung tumor SBRT treatments. These treatments are typically performed for five to 10 minutes, two or three days per week for one to two weeks. If you have been diagnosed with lung cancer, talk to your physician about whether you may be a candidate for this treatment.
Written By: Brian Williams
Original Date: November 7 2017