Tracking Tumors Enters a New Dimension

Lung cancer survival may improve with more accurate 4D tracking technique

(RxWiki News) Four-dimensional imaging brings a live-action view to a 3D picture. A new version of this technique may help deliver higher levels of radiation to tumors while sparing healthy tissue.

In a recent study, medical physicists have applied new technology to existing scanning equipment to better track moving tumors and deliver radiation therapy.

These scientists remarked that this study's results demonstrate the feasibility in a clinical setting. Additionally, these new technology should be available to patients in the next few years.

"Technology is advancing - stay informed."

Dr. Ivan Buzurovic, PhD, a medical physics resident and researcher in the Department of Radiation Oncology at Thomas Jefferson University and Jefferson’s Kimmel Cancer Center in Philadelphia, led the study showing that new software, hardware and robotic technology could be integrated with existing 4D CT equipment. CT, or computed tomography, uses x-rays to create pictures of the inside of the body.

Professor Buzurovic’s team also validated that their tumor tracking system could follow desired trajectories. The ability to better track constantly moving tumors during radiation therapy will prevent too much radiation from being administered to unnecessary areas, according to scientists.

Lung tumors have been difficult targets for radiation therapy because a patient’s breathing causes tumors to shift position from day to day during the course of treatment. Heart motions can also move and deform tumors.

Prior research has found that higher doses of radiation can improve survival rates. Because of tumor movements, however, oncologists have had to apply radiation in areas than go beyond the tumor to make sure it was reaching all the cancer.

Often, the radiation cannot avoid large areas of healthy tissue and critical organs that are close to the tumors. Tests of the new tracking system showed that treatment areas could be better targeted. Investigators commented that areas set for treatment could be 20 to 30 percent less in volume for medium-size tumors and 50 percent less for small size tumors.

“This new technique shrinks the margin, and radiation oncologists would be able to administer more radiation and faster to the tumor than conventional methods," said Adam P. Dicker, MD, Chairman of the Department of Radiation Oncology at Thomas Jefferson University.

"A higher, more targeted dose means a better cure in lung cancer."

Professor Buzurovic told the dailyRx News, “With the implementation of this tracking technique, it would be possible to administer radiation dose to the tumor faster and more efficaciously than conventional methods."

"Tracking and active dose delivery is capable of compensating for tumor motion in all directions, thereby permitting the use of smaller error margins and eliminating the need to include large amounts of normal tissue in the radiation beam."

"As a result, the tumor can receive higher dose while collateral damage to adjacent normal tissue is minimized, leading to better probability of cure.”

This study was published in the November issue of Medical Physics, the journal of American Association of Physicists in Medicine. No conflicts of interest were reported.

Review Date: 
November 20, 2012