October 30, 2007 - According to a study presented at the Plenary I session on Oct. 29, 2007, at the American Society for Therapeutic Radiology and Oncology (ASTRO) 49th Annual Meeting in Los Angeles, CA, a new method to standardize the reporting of radiation dose volumes in the use of four-dimensional computed tomography (4D-CT) can lead to a more accurate radiation dose to the lungs in lung cancers, thereby lowering the risk of lung injury.
The study involved 40 stage III/IV nonsmall cell lung cancer patients who received a 4D-CT and a fast free-breathing helical CT (FBCT) scan. The study shows large differences in reported dose-volume histogram values when different lung volume definitions were used. The study also found that population-based relationships among different lung volumes can be used to convert these values into a more standardized definition of dose-volume.
According to the study, 4D-CT is a series of CT scans that measure how much a tumor moves when a patient breathes and allows radiation oncologists to personalize radiation treatment for this motion. Radiation doses are measured by the volume of a person’s lungs and lung volumes change during each phase of the breathing cycle. Because of this, there is a substantial difference in the reporting of the amount of normal lung tissue that is exposed to radiation.
The study sought to improve the accuracy of dose-volume reporting, lower the risk of lung injury to lung cancer patients.
For more information: www.rtanswers.org and www.astro.org
April 29, 2026 
