David Dubin, MD, chief of radiation oncology
“Our treatment of patients has really advanced just in the last five years with newer, more accurate technology,” shares Dr. David Dubin, chief of radiation oncology at The Lefcourt Family Cancer Treatment and Wellness Center at Englewood Health. “With more sophisticated radiation technology and advanced imaging capabilities, we now can provide treatments that are easier on the patient and even more effective.”
Dr. Dubin explains how these advancements are expanding medicine’s ability to treat more challenging tumors in lung, prostate, and breast cancers.
Stereotactic Body Radiation Therapy (SBRT)
Our goal is to treat a tumor with minimal healthy tissue exposed to radiation. The challenge is that, outside of the brain (which can be immobilized), parts of the body are moving all the time. For example, the lungs are not static. They move up and down, forward and back. It is a challenge to minimize the amount of damage to healthy tissue. We need to know at any point in time, where the tumor is in that moment. It takes a lot of technology. As part of treatment planning, a 4-dimension CT scan is taken so that every location can be identified during treatment. A lot of work goes into the treatment planning, with the help of two radiation therapy physicists.
In lung cancer, radiation therapy is used to treat very localized, small tumors that have not spread and can easily be seen on a CT scan, and for patients who are not candidates for surgery due to prior lung surgeries, who have more advanced disease or advanced age. With SBRT, the side effects and complications are generally less than surgery and the results are excellent.
For SBRT we have several options. Either we suppress diaphragmatic motion by compressing the abdomen. If that is uncomfortable or unsuccessful, we utilize “gating,” in which the machine is turned on only during part of the breathing cycle, when the tumor is in the proper location. This avoids treating normal, unaffected lung. We also utilize makers placed by our pulmonologists near the tumor, which can be imaged in real time and compared to a computer model. This assures proper delivery of the radiation. The most common protocol for SBRT for lung cancer is three treatments, one week apart. SBRT has a 90-percent cure rate for very small lung cancers—it’s a real advance.
In men, the prostate sits just against the wall of the rectum. The rectum can move a lot, with digestion, gas, stool, etc. When treating prostate cancer with radiation therapy, we place tiny metallic markers, or “beacons,” into the prostate that can be identified on a CT scan, and then during real-time treatment using radiofrequency. The technological intelligence of our systems allows a tumor to be targeted, like GPS, so that higher-dose, more accurate treatments can be delivered.
To minimize side effects, Dr. Dubin injects a bio gel in the space between the prostate and the rectum prior to treatment, which moves the rectal wall away from the prostate and protects the rectum during treatment. With SBRT, Englewood Health can treat prostate cancer in five every-other-day sessions. The standard treatment would be 8–9 weeks of daily treatment.
Intensity Modulated Radiation Therapy (IMRT) combined with Deep Inspiration Breath Hold (DIBH) for treating Breast Cancer
To treat breast cancer, Englewood Hospital’s radiation therapy team uses prone breast positioning, whereby the patient lies on her stomach and the breast hangs into a well, falling away from the body, to protect the heart and lungs.
For patients who need to be treated lying on their backs, the team practices Deep Inspiration Breath Hold (DIBH), during which the patient holds her breath briefly, on cue. By expanding the lungs, the heart is pushed down and back, further away from the area that is being radiated. This requires an advanced digital camera system to identify exactly where the body is at any point. Englewood Hospital is one of the only facilities using this new system, which ensures more accuracy and less healthy tissue
Posted September 2018