New Tumor Tracking Technique Could Improve Cancer Treatments
While radiation therapy is an important procedure for cancer patients, current techniques have some harmful side effects because it not only affects the cancerous cells, but also healthy tissue as well. Medical physicists at Thomas Jefferson University and Jefferson’s Kimmel Cancer Center have demonstrated a new tumor-tracking technique that can help minimize the amount of radiation delivered to healthy tissue.
Robotic Technique May Decrease the Effect on Healthy Tissue by 50%
Respiratory and cardiac motions have been found to displace and deform tumors in the lung, pancreas, liver, breast, and other organs. Because of this, radiation oncologists must expand the margin during radiotherapy, and consequently a large volume of healthy tissue is irradiated, and critical organs adjacent to the tumor are sometimes difficult to spare.
Jefferson researchers have developed a new 4D robotic technique that can help shrink that margin by better predicting and continuously tracking tumors during radiotherapy, preventing unnecessary amounts of radiation affecting critical organs and surrounding healthy tissues by up to 50% in some cases. This also allows the radiation oncologist to maximize the dose the tumor receives.
In the technique, the robotic system, which is programmed with algorithms developed to predict and tract tumor motion in three-dimensional space, can automatically adjust so that the position of the tumor remains stationary during treatment. When the device was tested, the irradiated planning target volume (PTV) was 20 to 30% less for a medium size tumor and more than 50% for small size tumors. In larger tumors up to 2.5 cm, irradiated PTV was two times smaller when the tracking mechanism was applied.
The study findings suggest that the use of tumor tracking technology during radiotherapy treatment for lung cancer would result in significant reduction in dose to the healthy tissue, potentially decreasing the probability or severity of side effects, says co-author Dr. Yan Yu PhD, director of Medical Physics at Thomas Jefferson.
Radiation therapy itself is painless and without sensation, however side effects can include radiation nausea, hair loss, fatigue, low blood count and skin reactions and scarring.
The research study was published online Feb 1 in the journal Physics in Medicine and Biology.