The small-animal radiation research platform (SARRP): dosimetry of a focused lens system

Deng, Hua; Kennedy, C.; Armour, Elwood P.; Tryggestad, E.; Ford, Eric; McNutt, Todd; Jiang, Licai; Wong, John W.

doi:10.1088/0031-9155/52/10/007

Cited by 52 publications

(49 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both HSCs and MSCs are implicated in the repair of irradiation damage of distal epithelial through their mobilization in the circulation (15)(16)(17). In this study, we aimed to investigate how irradiation affects bone marrow stem cells and residing microenvironment directly or indirectly by using a unique Small Animal Radiation Research Platform (SARRP) built by the Department of Radiation Oncology at Johns Hopkins University, in which computed tomography (CT), X-ray, and irradiation are integrated into a single system (18). We found that irradiation damaged the bone marrow microenvironment for stem cells, and our findings suggest that prevention of the damage during radiation therapy will be helpful for the recovery of bone injury.…”

mentioning

confidence: 99%

Irradiation induces bone injury by damaging bone marrow microenvironment for stem cells

Cao¹,

Frassica

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

219

200

View full text Add to dashboard Cite

Radiation therapy can result in bone injury with the development of fractures and often can lead to delayed and nonunion of bone. There is no prevention or treatment for irradiation-induced bone injury. We irradiated the distal half of the mouse left femur to study the mechanism of irradiation-induced bone injury and found that no mesenchymal stem cells (MSCs) were detected in irradiated distal femora or nonirradiated proximal femora. The MSCs in the circulation doubled at 1 week and increased fourfold after 4 wk of irradiation. The number of MSCs in the proximal femur quickly recovered, but no recovery was observed in the distal femur. The levels of free radicals were increased threefold at 1 wk and remained at this high level for 4 wk in distal femora, whereas the levels were increased at 1 wk and returned to the basal level at 4 wk in nonirradiated proximal femur. Free radicals diffuse ipsilaterally to the proximal femur through bone medullary canal. The blood vessels in the distal femora were destroyed in angiographic images, but not in the proximal femora. The osteoclasts and osteoblasts were decreased in the distal femora after irradiation, but no changes were observed in the proximal femora. The total bone volumes were not affected in proximal and distal femora. Our data indicate that irradiation produces free radicals that adversely affect the survival of MSCs in both distal and proximal femora. Irradiation injury to the vasculatures and the microenvironment affect the niches for stem cells during the recovery period.

show abstract

mentioning

confidence: 99%

Irradiation induces bone injury by damaging bone marrow microenvironment for stem cells

Cao¹,

Frassica

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

219

200

View full text Add to dashboard Cite

show abstract

“…Several laboratories are addressing this issue by developing methods for more precise small animal radiation therapy, including groups at Johns Hopkins University, [4][5][6][7][8][9][10] Princess Margaret Hospital, 11 and Washington University. [12][13][14][15][16] Our group has previously developed a method for precision irradiation of small animals by adapting an existing small animal microCT scanner with an x-ray tube operating at 70-120 kVp using a variable-aperture collimator with an aperture range of 1-102 mm at isocenter.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the effects of treatment planning variables in small animal radiotherapy dose distributions

et al. 2010

View full text Add to dashboard Cite

Purpose: Methods used for small animal radiation treatment have yet to achieve the same dose targeting as in clinical radiation therapy. Toward understanding how to better plan small animal radiation using a system recently developed for this purpose, the authors characterized dose distributions produced from conformal radiotherapy of small animals in a microCT scanner equipped with a variable-aperture collimator. Methods: Dose distributions delivered to a cylindrical solid water phantom were simulated using a Monte Carlo algorithm. Phase-space files for 120 kVp x-ray beams and collimator widths of 1-10 mm at isocenter were generated using BEAMnrc software, and dose distributions for evenly spaced beams numbered from 5 to 80 were generated in DOSXYZnrc for a variety of targets, including centered spherical targets in a range of sizes, spherical targets offset from centered by various distances, and various ellipsoidal targets. Dose distributions were analyzed using dose volume histograms. The dose delivered to a mouse bearing a spontaneous lung tumor was also simulated, and dose volume histograms were generated for the tumor, heart, left lung, right lung, and spinal cord. Results: Results indicated that for centered, symmetric targets, the number of beams required to achieve a smooth dose volume histogram decreased with increased target size. Dose distributions for noncentered, symmetric targets did not exhibit any significant loss of conformality with increasing offset from the phantom center, indicating sufficient beam penetration through the phantom for targeting superficial targets from all angles. Even with variable collimator widths, targeting of asymmetric targets was found to have less conformality than that of spherical targets. Irradiation of a mouse lung tumor with multiple beam widths was found to effectively deliver dose to the tumor volume while minimizing dose to other critical structures. Conclusions: Overall, this method of generating and analyzing dose distributions provides a quantitative method for developing practical guidelines for small animal radiotherapy treatment planning. Future work should address methods to improve conformality in asymmetric targets.

show abstract

“…One such system is the small animal radiation research platform (SARRP; Xstrahl Ltd, Surrey, United Kingdom), which incorporates cone-beam computed tomography (CBCT) imaging with delivery of radiation to a specific anatomic location in small animal, matching the clinical techniques in radiation therapy. 16 The SARRP comes with the additional benefit of a treatment planning system that can do image fusion, contouring, and dose-volume histogram calculations. Nevertheless, one advantage of our system is that it can be adapted according to the need and it is an example of alternate system configuration.…”

Section: Introductionmentioning

confidence: 99%

Advanced Small Animal Conformal Radiation Therapy Device

Sharma

Narayanasamy

Przybyla

et al. 2016

Technol Cancer Res Treat

View full text Add to dashboard Cite

We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made ''gantry'' and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

show abstract

The small-animal radiation research platform (SARRP): dosimetry of a focused lens system

Cited by 52 publications

References 10 publications

Irradiation induces bone injury by damaging bone marrow microenvironment for stem cells

Irradiation induces bone injury by damaging bone marrow microenvironment for stem cells

Investigation of the effects of treatment planning variables in small animal radiotherapy dose distributions

Advanced Small Animal Conformal Radiation Therapy Device

Contact Info

Product

Resources

About