Houston Methodist Clear Lake Hospital has installed a new radiation therapy system, which integrates imaging, beam delivery, and motion management to give physicians unmatched control of radiation therapy.
“This is a major step forward in cancer treatment,” said Twisha Verma, M.D., radiation oncologist at Houston Methodist Cancer Center at Clear Lake. “The new system allows us to limit side effects and reduce the impact on surrounding tissue while improving the delivery of radiation. It actually gives us a 4-D image as we work – a three-dimensional view of the tumor along with any movement – so that we can deliver radiation doses to a precise spot at the most opportune moment.”
The system, called TrueBeam, developed by Varian Medical Systems, is ideal for treating tumors of the lung, abdomen, breast, prostate, head, and neck.
One of the major advances of the TrueBeam is its GPS-like system for prostate cancer treatment, in which tiny markers are implanted in the patient for precise, real-time tracking of the tumor. “This is especially beneficial because the prostate can move slightly throughout a treatment session due to a full bladder or abdominal gas,” said Verma. “Now, we are able to adjust the delivery of radiation in real time to ensure we are hitting the tumor, even if there is slight movement during treatment.”
With this new technology, clinicians can correlate the tumor position in breast cancer patients in relation to the patient’s respiratory cycle. Using an infrared tracking camera, the system measures the patient’s respiratory pattern and range of motion. This allows the clinician to set gating thresholds that turn the radiation beam on and off automatically for maximum benefit.
“As the patient inhales, the heart is shifted away from the breast by the expanded lungs. This allows us to reduce the radiation exposure to the heart, especially for young woman or women with left-sided breast cancer, who are at increased risks,” said Verma. “The gating mechanism in the TrueBeam system allows us to rapidly deliver radiation doses when the patient’s heart and lungs are furthest from the tumor, limiting the amount of radiation those critical organs receive.”
The gating system can also be used with other forms of cancer, such as lung cancer, and will be used in stereotactic body radiation therapy, said Verma.
TrueBeam also allows for quicker treatment sessions – just a few minutes a day in most cases – and a more comfortable patient experience. For example, the system is quieter than traditional linear accelerators and there are enhanced communication capabilities that enable the patient to remain in constant contact with the operating therapist.
“Our success relies on our collaborative approach with patients,” said Verma. “The TrueBeam system gives our team another powerful tool that we can use to plan and deliver the best possible care.”