SU‐E‐T‐03: A Comparison of HDR Near Source Dosimetry Using a Treatment Planning System, Monte Carlo Simulation, and Radiochromic Film

A. Amoush, M. Luckstead, M. Lamba, H. Elson

Research output: Contribution to journalArticle

Abstract

Purpose: This study aimed to investigate the high dose rate (HDR) 192Ir brachytherapy, including near source dosimetry, of a catheter‐based applicator from 0.5 mm to 1 cm along the transverse axis. Methods: Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter‐based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the AAPM Updated Task Group 43 (TG‐43U1) dose calculation formalism. Results: Difference between dose measured using radiochromic film along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 24%±13%. Dose difference between the MC simulation along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 22.1%±3%. For distances from 1.5 mm to 1 cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3%. Conclusion: The TPS under‐predicts the dose at the surface of the applicator, i.e., 0.5 mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15% of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS and 7% of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3%.

Original languageEnglish (US)
Pages (from-to)203
Number of pages1
JournalMedical Physics
Volume40
Issue number6
DOIs
StatePublished - 2013

Fingerprint

Photons
Therapeutics
Catheters
Beta Particles
Brachytherapy
Uncertainty
Air
Electrons

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

Cite this

SU‐E‐T‐03 : A Comparison of HDR Near Source Dosimetry Using a Treatment Planning System, Monte Carlo Simulation, and Radiochromic Film. / Amoush, A.; Luckstead, M.; Lamba, M.; Elson, H.

In: Medical Physics, Vol. 40, No. 6, 2013, p. 203.

Research output: Contribution to journalArticle

@article{b3ee60c295f346a19e2ebfd9bd2acb0e,
title = "SU‐E‐T‐03: A Comparison of HDR Near Source Dosimetry Using a Treatment Planning System, Monte Carlo Simulation, and Radiochromic Film",
abstract = "Purpose: This study aimed to investigate the high dose rate (HDR) 192Ir brachytherapy, including near source dosimetry, of a catheter‐based applicator from 0.5 mm to 1 cm along the transverse axis. Methods: Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter‐based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the AAPM Updated Task Group 43 (TG‐43U1) dose calculation formalism. Results: Difference between dose measured using radiochromic film along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 24{\%}±13{\%}. Dose difference between the MC simulation along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 22.1{\%}±3{\%}. For distances from 1.5 mm to 1 cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3{\%}. Conclusion: The TPS under‐predicts the dose at the surface of the applicator, i.e., 0.5 mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15{\%} of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS and 7{\%} of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3{\%}.",
author = "A. Amoush and M. Luckstead and M. Lamba and H. Elson",
year = "2013",
doi = "10.1118/1.4814437",
language = "English (US)",
volume = "40",
pages = "203",
journal = "Medical Physics",
issn = "0094-2405",
publisher = "AAPM - American Association of Physicists in Medicine",
number = "6",

}

TY - JOUR

T1 - SU‐E‐T‐03

T2 - A Comparison of HDR Near Source Dosimetry Using a Treatment Planning System, Monte Carlo Simulation, and Radiochromic Film

AU - Amoush, A.

AU - Luckstead, M.

AU - Lamba, M.

AU - Elson, H.

PY - 2013

Y1 - 2013

N2 - Purpose: This study aimed to investigate the high dose rate (HDR) 192Ir brachytherapy, including near source dosimetry, of a catheter‐based applicator from 0.5 mm to 1 cm along the transverse axis. Methods: Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter‐based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the AAPM Updated Task Group 43 (TG‐43U1) dose calculation formalism. Results: Difference between dose measured using radiochromic film along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 24%±13%. Dose difference between the MC simulation along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 22.1%±3%. For distances from 1.5 mm to 1 cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3%. Conclusion: The TPS under‐predicts the dose at the surface of the applicator, i.e., 0.5 mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15% of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS and 7% of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3%.

AB - Purpose: This study aimed to investigate the high dose rate (HDR) 192Ir brachytherapy, including near source dosimetry, of a catheter‐based applicator from 0.5 mm to 1 cm along the transverse axis. Methods: Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter‐based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the AAPM Updated Task Group 43 (TG‐43U1) dose calculation formalism. Results: Difference between dose measured using radiochromic film along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 24%±13%. Dose difference between the MC simulation along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 22.1%±3%. For distances from 1.5 mm to 1 cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3%. Conclusion: The TPS under‐predicts the dose at the surface of the applicator, i.e., 0.5 mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15% of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS and 7% of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3%.

UR - http://www.scopus.com/inward/record.url?scp=85024794763&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85024794763&partnerID=8YFLogxK

U2 - 10.1118/1.4814437

DO - 10.1118/1.4814437

M3 - Article

AN - SCOPUS:85024794763

VL - 40

SP - 203

JO - Medical Physics

JF - Medical Physics

SN - 0094-2405

IS - 6

ER -