Volume 3 Supplement 1

Current and Future Applications of Focused Ultrasound 2014. 4th International Symposium: abstracts

Open Access

Thermal dose and radiation dose comparison based on cell survival

  • Meredith Lee1,
  • David Schlesinger2,
  • Gail ter Haar3,
  • Benjamin Sela1,
  • Matt Eames1,
  • John Snell1,
  • Arik Hananel1,
  • Neal Kassell1,
  • Jason Sheehan2,
  • James Larner2 and
  • Jean-Francois Aubry4
Journal of Therapeutic Ultrasound20153(Suppl 1):P26

https://doi.org/10.1186/2050-5736-3-S1-P26

Published: 30 June 2015

Background/introduction

The biologic dose response curves of thermal dose and absorbed radiation dose have not been compared to each other even though they have both been extensively investigated separately and combined. Although heat and radiation produce cell kill by different biological mechanisms (Thermal dose denatures proteins and the radiation dose causes DNA damage) a comparison of dose response curves is possible using the endpoint of cell survival.

Methods

Survival curves for both thermal and radiation doses were extracted for three different types of cells from previously published data. Using models based on the beam shapes of the current clinical systems for the dose profile, the survival curves were generated and the survival profiles were compared for both modalities, Focused Ultrasound (FUS) and Gamma Knife (GK), for a thalamotomy. The thermal dose profile was calculated according to Dewey (1994), from temperature maps simulated with a 3D finite differences time domain code solving the bio-heat equation with a heat deposition term dependent on the pressure field. Radiosurgery dose distributions were exported from the Gamma Knife treatment planning software (Leksell GammaPlan versions 8.0 - 10.1, Elekta AB, Stockholm) with the smallest target as an input.

Results and conclusions

The comparison showed that focused ultrasound exhibits a steeper dose and survival profile than gamma knife. As shown in Figure 1, a smaller percentage of cells are dead a short distance away from the FUS target compared with GK. Also, cell death drops more gradually for GK than FUS. Our results establish that the penumbra is steeper for FUS than GK and have implications for making treatment decisions as well as for rationally combing the two modalities.
Figure 1

Fraction of cell death radially from the focus of the gamma beams and focused ultrasound beams.

Declarations

Acknowledgements (Funding)

Focused Ultrasound Foundation

Authors’ Affiliations

(1)
Focused Ultrasound Foundation
(2)
University of Virginia
(3)
The Institute of Cancer Research
(4)
Institut Langevin

References

  1. Dewey W: Arrhenius relationships from the molecule and cell to the clinic. International journal of hyperthermia. 1994, 10 (4): 457-483. 10.3109/02656739409009351.View ArticlePubMedGoogle Scholar

Copyright

© Lee et al; licensee BioMed Central Ltd. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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