Histogram Analysis and Heterogeneous Radial Changes Using ADC Map Images in Metastatic Brain Tumors for Dose Painting Intent.

Background: Our goal in this study was to examine the heterogeneous radial changes within tumors using histogram analysis and determine whether this method could assist in the implementation of targeted radiation painting. Materials and Methods: The diffusion-weighted imaging image data for 25 patients with primary lung cancer was examined. For patients with multiple metastases, the largest tumor diameter was considered, and three different radial categories were selected to assess heterogeneity changes. Finally, the histogram parameters of apparent diffusion coefficient (ADC) were compared among the 25 patients, and the Results: The obtained outcome of our study demonstrated that in the central region of the tumor, up to a (0-0.3)r (tumor radius of the tumor), the tumor heterogeneity remains constant, and there is no significant difference in the ADC histogram percentiles of 25, 50, and 75. In the peripheral region of the tumor, at a distance away from the center, the heterogeneity level varies. Conclusions: These findings indicate that this method has the potential to separate the boundary between the center of the tumor and its periphery in terms of the level of heterogeneity, which is one of the requirements of dose painting.