skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model

Authors:
 [1];  [1];  [2];  [3];  [1]
  1. J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville FL 32611-6131 USA
  2. Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore MD 21231 USA
  3. Department of Radiology, Johns Hopkins University School of Medicine, Baltimore MD 21231 USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1401510
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 44; Journal Issue: 1; Related Information: CHORUS Timestamp: 2017-10-20 17:09:36; Journal ID: ISSN 0094-2405
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
United States
Language:
English

Citation Formats

Geyer, Amy M., Schwarz, Bryan C., Hobbs, Robert F., Sgouros, George, and Bolch, Wesley E.. Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model. United States: N. p., 2017. Web. doi:10.1002/mp.12002.
Geyer, Amy M., Schwarz, Bryan C., Hobbs, Robert F., Sgouros, George, & Bolch, Wesley E.. Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model. United States. doi:10.1002/mp.12002.
Geyer, Amy M., Schwarz, Bryan C., Hobbs, Robert F., Sgouros, George, and Bolch, Wesley E.. Thu . "Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model". United States. doi:10.1002/mp.12002.
@article{osti_1401510,
title = {Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model},
author = {Geyer, Amy M. and Schwarz, Bryan C. and Hobbs, Robert F. and Sgouros, George and Bolch, Wesley E.},
abstractNote = {},
doi = {10.1002/mp.12002},
journal = {Medical Physics},
number = 1,
volume = 44,
place = {United States},
year = {Thu Jan 19 00:00:00 EST 2017},
month = {Thu Jan 19 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/mp.12002

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • The bone marrow syndrome was investigated in dogs subjected to 400 R whole-body irradiation. Hematological and morphological examinations of peripheral blood revealed progressive pancytopenia. After the early disappearance of the youngest nucleated bone marrow cells, the bone marrow cellularity dropped to a low level in 5 days and remained constant till death. Quantitative data obtained in the first 24 hrs after irradiation showed an immediate and nearly complete impairment of hematopoiesis with the normoblasts having the highest radiosensitivity. An increase in the normoblast, lymphocyte, reticulum cell, and plasmocyte counts was observed after 6 days, while the number of myeloid cellsmore » decreased further. The increase suggested a tendency to recovery in the preterminal phase. A relation may exist between the increase of the lymphocyte and reticulum-like cell counts and hematological recovery. (INIS)« less
  • Skeletal dosimetry based on {mu}CT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the {mu}CT images for skeletal dosimetry, spongiosa voxels in the skeletons were replaced at run time by so-called micromatrices, which have exactly the size of a spongiosa voxel and contain segmented trabecular bone and marrow microvoxels. A cluster (=parallelepiped) of 2x2x2=8 micromatrices was used systematically and periodically throughout the spongiosa volume during the radiation transport calculation. Systematic means that whenmore » a particle leaves a spongiosa voxel to enter into a neighboring spongiosa voxel, then the next micromatrix in the cluster will be used. Periodical means that if the particle travels through more than two spongiosa voxels in a row, then the cluster will be repeated. Based on the bone samples available at the time, clusters of up to 3x3x3=27 micromatrices were studied. While for a given trabecular bone volume fraction the whole-body RBM equivalent dose showed converging results for cluster sizes between 8 and 27 micromatrices, this was not the case for the BSC equivalent dose. The BSC equivalent dose seemed to be very sensitive to the number, form, and thickness of the trabeculae. In addition, the cluster size and/or the microvoxel resolution were considered to be possible causes for the differences observed. In order to resolve this problem, this study used a bone sample large enough to extract clusters containing up to 8x8x8=512 micromatrices and which was scanned with two different voxel resolutions. Taking into account a recent proposal, this investigation also calculated the BSC equivalent dose on medullary surfaces of cortical bone in the arm and leg bones. The results showed (1) that different voxel resolutions have no effect on the RBM equivalent dose but do influence the BSC equivalent dose due to voxel effects by up to 5% for incident photon energies up to 200 keV, (2) that the whole-body BSC equivalent dose calculated with a cluster with 2x2x2=8 micromatrices is consistent with results received with clusters of up to 8x8x8=512 micromatrices, and (3) that for external whole-body exposure the inclusion of the BSC on medullary surfaces of cortical bone has a negligible effect on the whole-body BSC equivalent dose.« less
  • Purpose: Limitations seen in previous skeletal dosimetry models, which are still employed in commonly used software today, include the lack of consideration of electron escape and cross-fire from cortical bone, the modeling of infinite spongiosa, the disregard of the effect of varying cellularity on active marrow self-irradiation, and the lack of use of the more recent ICRP definition of a 50 micron surrogate tissue region for the osteoprogenitor cells - shallow marrow. These limitations were addressed in the present dosimetry model. Methods: Electron transport was completed to determine specific absorbed fractions to active marrow and shallow marrow of the skeletalmore » regions of the adult female. The bone macrostructure was obtained from the whole-body hybrid computational phantom of the UF series of reference phantoms, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 year-old female cadaver. The target tissue regions were active marrow and shallow marrow. The source tissues were active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume and cortical bone surfaces. The marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or modeled analytically. Results: The method of combining macro- and microstructure absorbed fractions calculated using MCNPX electron transport was found to yield results similar to those determined with the PIRT model for the UF adult male in the Hough et al. study. Conclusion: The calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) and did not follow current models used in nuclear medicine dosimetry at high energies (due to that models use of an infinite expanse of trabecular spongiosa)« less
  • The relationship between marrow distribution as imaged with /sup 99m/Tc sulfur colloid and histologic estimate of bone marrow cellularity was examined in 101 patients. The patients were divided into three groups according to marrow cellularity: normocellular, hyperellular or hypocellular marrow. The marrow distribution of these patients was graded as extended, not extended or not visualized. A general association between marrow cellularity and marrow distribution was found. Seventy-seven percent of patients with normocellular marrow had limitation of marrow within normal sites and a similar number of patients with reactive hypercellular marrow had marrow extension. On analysis of the patients that weremore » exceptions to this generalization the following observations were made. In patients in whom the marrow is hypercellular and infiltrated with abnormal cells or tissue the marrow distribution may not be visualized with radiocolloid. Stimulation of hematopoiesis may result in marrow hypercellularity without marrow extension beyond the usual sites. Stimulation of one or more hematopoietic cell lines may result in marrow extension without marrow hypercellularity, suggesting an impariment of hematopoietic cell response. Peripheral marrow extension as observed with radiocolloid, therefore, is not simply a reflection of marrow hypercellularity but probably represents a response to the bone marrow stroma to situations in which one or more hematopoietic cell lines is stimulated. (auth)« less