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SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers.

Publication ,  Conference
Mao, R; Zhang, Y; Ren, L; Tian, L; Gao, R; Ge, H; Yin, F
Published in: Med Phys
June 2015

PURPOSE: To evaluate the dosimetry of microscopic disease (MD) region of lung cancer in stereotactic body radiation therapy (SBRT). METHODS: For simplicity, we assume organ moves along one dimension. The probability distribution function of tumor position was calculated according to the breathing cycle. The dose to the MD region was obtained through accumulating the treatment planning system calculated doses at different positions in a breathing cycle. A phantom experiment was then conducted to validate the calculated results using a motion phantom (The CIRS 'Dynamic' Thorax Phantom). The simulated breathing pattern used a cos4(x) curve with an amplitude of 10mm. A 3-D conformal 7-field plan with 6X energy was created and the dose was calculated in the average intensity projection (AIP) simulation CT images. Both films (EBT2) and optically stimulated luminescence (OSL) detectors were inserted in the target of the phantom to measure the dose during radiation delivery (Varian Truebeam) and results were compared to planning dose parameters. RESULTS: The Gamma analysis (3%/3mm) between measured dose using EBT2 film and calculated dose using AIP was 80.5%, indicating substantial dosimetric differences. While the Gamma analysis (3%/3mm) between measured dose using EBT2 and accumulated dose using 4D-CT was 98.9%, indicating the necessity of dose accumulation using 4D-CT. The measured doses using OSL and theoretically calculated doses using probability distribution function at the corresponding position were comparable. CONCLUSION: Use of static dose calculation in the treatment planning system could substantially underestimate the actually delivered dose in the MD region for a moving target. Funding Supported by NSFC, No.81372436.

Duke Scholars

Published In

Med Phys

DOI

ISSN

0094-2405

Publication Date

June 2015

Volume

42

Issue

6

Start / End Page

3400

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Mao, R., Zhang, Y., Ren, L., Tian, L., Gao, R., Ge, H., & Yin, F. (2015). SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers. In Med Phys (Vol. 42, p. 3400). United States. https://doi.org/10.1118/1.4924655
Mao, R., Y. Zhang, L. Ren, L. Tian, R. Gao, H. Ge, and F. Yin. “SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers.” In Med Phys, 42:3400, 2015. https://doi.org/10.1118/1.4924655.
Mao R, Zhang Y, Ren L, Tian L, Gao R, Ge H, et al. SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers. In: Med Phys. 2015. p. 3400.
Mao, R., et al. “SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers.Med Phys, vol. 42, no. 6, 2015, p. 3400. Pubmed, doi:10.1118/1.4924655.
Mao R, Zhang Y, Ren L, Tian L, Gao R, Ge H, Yin F. SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers. Med Phys. 2015. p. 3400.

Published In

Med Phys

DOI

ISSN

0094-2405

Publication Date

June 2015

Volume

42

Issue

6

Start / End Page

3400

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences