Evaluation of Functional Marrow Irradiation Based on Skeletal Marrow Composition Obtained Using Dual-Energy Computed Tomography

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• 作者：Taiki Magome ; PhD^&lowast ; ; ^&dagger ; ; ^&Dagger ; ; Jerry Froelich ; MD^§ ; ; Yutaka Takahashi ; PhD^&dagger ; ; ^|| ; Luke Arentsen ; PhD^¶ ; ; Shernan Holtan ; MD^# ; Michael R. Verneris ; MD^# ; Keenan Brown ; PhD^&lowast ; &lowast ; ; Akihiro Haga ; PhD^&Dagger ; ; Keiichi Nakagawa ; MD ; PhD^&Dagger ; ; Jennifer L. Holter Chakrabarty ; MD^&dagger ; &dagger ; ; Sebastian Giebel ; MD^&Dagger ; &Dagger ; ; Jeffrey Wong ; MD^§ ; § ; ; Kathryn Dusenbery ; MD^¶ ; ; Guy Storme ; MD ; PhD^|||| ; Susanta K. Hui ; PhD ; DABR^&dagger ; ; ^¶ ; ; ^§ ; § ; ; ^{shui@coh.org" class="auth_mail" title="E-mail the corresponding author}
• 刊名：International Journal of Radiation Oncology*Biology*Physics
• 出版年：2016
• 出版时间：1 November 2016
• 年：2016
• 卷：96
• 期：3
• 页码：679-687
• 全文大小：1750 K

文摘

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.