1. Evaluation of Functional Marrow Irradiation Based on Skeletal Marrow Composition Obtained Using Dual-Energy Computed Tomography.
- Author
-
Magome, Taiki, Froelich, Jerry, Takahashi, Yutaka, Arentsen, Luke, Holtan, Shernan, Verneris, Michael R., Brown, Keenan, Haga, Akihiro, Nakagawa, Keiichi, Holter Chakrabarty, Jennifer L., Giebel, Sebastian, Wong, Jeffrey, Dusenbery, Kathryn, Storme, Guy, and Hui, Susanta K.
- Subjects
- *
BONE marrow , *LEUKEMIA treatment , *CANCER radiotherapy , *MEDICAL cadavers , *TOTAL body irradiation , *COMPUTED tomography , *DEAD , *DIAGNOSTIC imaging , *LEUKEMIA , *DOSE-response relationship (Radiation) , *RADIATION doses , *RADIOTHERAPY , *RESEARCH funding ,RESEARCH evaluation - Abstract
Purpose: To develop an imaging method to characterize and map marrow composition in the entire skeletal system, and to simulate differential targeted marrow irradiation based on marrow composition.Methods and Materials: Whole-body dual energy computed tomography (DECT) images of cadavers and leukemia patients were acquired, segmented to separate bone marrow components, namely, bone, red marrow (RM), and yellow marrow (YM). DECT-derived marrow fat fraction was validated using histology of lumbar vertebrae obtained from cadavers. The fractions of RM (RMF = RM/total marrow) and YMF were calculated in each skeletal region to assess the correlation of marrow composition with sites and ages. Treatment planning was simulated to target irradiation differentially at a higher dose (18 Gy) to either RM or YM and a lower dose (12 Gy) to the rest of the skeleton.Results: A significant correlation between fat fractions obtained from DECT and cadaver histology samples was observed (r=0.861, P<.0001, Pearson). The RMF decreased in the head, neck, and chest was significantly inversely correlated with age but did not show any significant age-related changes in the abdomen and pelvis regions. Conformity of radiation to targets (RM, YM) was significantly dependent on skeletal sites. The radiation exposure was significantly reduced (P<.05, t test) to organs at risk (OARs) in RM and YM irradiation compared with standard total marrow irradiation (TMI).Conclusions: Whole-body DECT offers a new imaging technique to visualize and measure skeletal-wide marrow composition. The DECT-based treatment planning offers volumetric and site-specific precise radiation dosimetry of RM and YM, which varies with aging. Our proposed method could be used as a functional compartment of TMI for further targeted radiation to specific bone marrow environment, dose escalation, reduction of doses to OARs, or a combination of these factors. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF