Treatments For Lung Cancer Stage 3

Treatments For Lung Cancer Stage 3

4D Computed Tomography and Gating

 

A problem for most external radiation systems is that lung tumors often move when you breathe—interfering imaging tests and forcing radiation oncologists to expand the treatment area so no cancer is missed. While holding your breath can help, many lung patients can’t do so for very long and the effort doesn’t guarantee accuracy.

Because the lung is a constantly moving organ, our team uses four-dimensional computed tomography (4D CT) scans to help guide treatment. This advanced scanning technique helps determine the tumor’s movement within the body, so that radiation can be adjusted to target the cancer and not surrounding normal tissues.

We use our sophisticated 4D computerized tomography (CT) scanner before lung cancer treatment, to take images of the tumor throughout your breathing cycle. Sometimes, it turns out the tumor doesn’t move much. But in many cases, our team uses the scans to determine the best point in your breathing cycle (gating) to deliver treatment, providing more refined therapy and sparing healthy lung tissue.

To achieve this goal, you will receive a four-dimensional CT (4D CT) that allows the physician to track your tumor’s motion and draw an area that captures this trajectory. This same CT will be used to calculate the radiation doses for planning. We also will be applying gentle pressure below your sternum bone to encourage you to take shallower breaths during the CT scan and treatment, reducing lung tumor motion. With more limited lung motion from our compression technique and acquiring 4D CT information, we can reduce normal lung tissues' radiation exposure compared to older techniques due to a much high level of certainty that the tumor is now in the field of radiation.

Stereotactic Ablative Body Radiotherapy (SABR)

SABR, also referred to as Stereotactic Body Radiation therapy (SBRT), is a technologically innovative form of radiation treatment that enables delivery of high doses of radiation to the tumor over a shorter number of treatments. In published studies, this has been shown to confer a primary tumor control rate exceeding 80 percent. At time of its initial development, SABR was restricted to frail and elderly patients who were not medically fit to tolerate surgery.

Stereotactic ablative radiotherapy (SABR) is a new type of radiotherapy. It’s also known as stereotactic body radiotherapy (SBRT). You may have heard of Cyberknife®, which is a type of SABR. SABR is not available for pancreatic cancer on the NHS, but it may be available as part of a clinical trial.

Currently, SABR is being offered to our patients in two scenarios: (1) to those patients whose medical conditions preclude them from surgery after evaluation by a thoracic surgeon and (2) those patients who refuse surgery. Research studies are currently being done to examine SABR for patients who are also healthy surgical candidates, and these results will be available over the coming years.

SABR delivers a higher dose of radiotherapy at each treatment. Because the dose is higher, you will usually only need three to five treatments over one to two weeks. However, each treatment session will take longer than other types of radiotherapy. It is important that this treatment is carried out very accurately. This is to reduce the risk of damage to healthy tissues from the high dose of radiation.

At City of Hope, we use a form of radiation delivery known as intensity modulated radiation therapy (IMRT) for SABR treatment. IMRT allows for the radiation beam to be blocked in specific areas during the therapy session, minimizing exposure to normal tissues.

Some research has suggested that SABR may be effective in helping to control pancreatic cancer. But there is no evidence to show that it is more effective than other types of radiotherapy. It may be more convenient because you will need fewer treatments. But there is a risk of damage to the stomach or bowel from the high dose of radiation, which could cause side effects. We need more research into SABR for pancreatic cancer.