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Title: Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system

Abstract

Purpose: In respiratory-gated radiation therapy, a baseline shift decreases the accuracy of target coverage and organs at risk (OAR) sparing. The effectiveness of audio-feedback and audio-visual feedback in correcting the baseline shift in the breathing pattern of the patient has been demonstrated previously. However, the baseline shift derived from the intrafraction motion of the patient's body cannot be corrected by these methods. In the present study, the authors designed and developed a simple and flexible system. Methods: The system consisted of a web camera and a computer running our in-house software. The in-house software was adapted to template matching and also to no preimage processing. The system was capable of monitoring the baseline shift in the intrafraction motion of the patient's body. Another marker box was used to monitor the baseline shift due to the flexible setups required of a marker box for gated signals. The system accuracy was evaluated by employing a respiratory motion phantom and was found to be within AAPM Task Group 142 tolerance (positional accuracy <2 mm and temporal accuracy <100 ms) for respiratory-gated radiation therapy. Additionally, the effectiveness of this flexible and independent system in gated treatment was investigated in healthy volunteers, in terms ofmore » the results from the differences in the baseline shift detectable between the marker positions, which the authors evaluated statistically. Results: The movement of the marker on the sternum [1.599 {+-} 0.622 mm (1 SD)] was substantially decreased as compared with the abdomen [6.547 {+-} 0.962 mm (1 SD)]. Additionally, in all of the volunteers, the baseline shifts for the sternum [-0.136 {+-} 0.868 (2 SD)] were in better agreement with the nominal baseline shifts than was the case for the abdomen [-0.722 {+-} 1.56 mm (2 SD)]. The baseline shifts could be accurately measured and detected using the monitoring system, which could acquire the movement of the marker on the sternum. The baseline shift-monitoring system with the displacement-based methods for highly accurate respiratory-gated treatments should be used to make most of the displacement-based gating methods. Conclusions: The advent of intensity modulated radiation therapy and volumetric modulated radiation therapy facilitates margin reduction for the planning target volumes and the OARs, but highly accurate irradiation is needed to achieve target coverage and OAR sparing with a small margin. The baseline shifts can affect treatment not only with the respiratory gating system but also without the system. Our system can manage the baseline shift and also enables treatment irradiation to be undertaken with high accuracy.« less

Authors:
; ; ; ; ; ;  [1];  [2];  [2]
  1. Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation of Cancer Research, Tokyo 1358550 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
22098549
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 38; Journal Issue: 7; Other Information: (c) 2011 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ABDOMEN; ACCURACY; CAMERAS; FEEDBACK; IRRADIATION; MANAGEMENT; PATIENTS; PHANTOMS; RADIATION MONITORING; RADIOTHERAPY; RESPIRATION; TOLERANCE

Citation Formats

Tachibana, Hidenobu, Kitamura, Nozomi, Ito, Yasushi, Kawai, Daisuke, Nakajima, Masaru, Tsuda, Akihisa, Shiizuka, Hisao, Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, Tokyo 1130032, and Department of Information Design, Kogakuin University, Tokyo 1638677. Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system. United States: N. p., 2011. Web. doi:10.1118/1.3598434.
Tachibana, Hidenobu, Kitamura, Nozomi, Ito, Yasushi, Kawai, Daisuke, Nakajima, Masaru, Tsuda, Akihisa, Shiizuka, Hisao, Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, Tokyo 1130032, & Department of Information Design, Kogakuin University, Tokyo 1638677. Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system. United States. doi:10.1118/1.3598434.
Tachibana, Hidenobu, Kitamura, Nozomi, Ito, Yasushi, Kawai, Daisuke, Nakajima, Masaru, Tsuda, Akihisa, Shiizuka, Hisao, Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, Tokyo 1130032, and Department of Information Design, Kogakuin University, Tokyo 1638677. Fri . "Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system". United States. doi:10.1118/1.3598434.
@article{osti_22098549,
title = {Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system},
author = {Tachibana, Hidenobu and Kitamura, Nozomi and Ito, Yasushi and Kawai, Daisuke and Nakajima, Masaru and Tsuda, Akihisa and Shiizuka, Hisao and Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, Tokyo 1130032 and Department of Information Design, Kogakuin University, Tokyo 1638677},
abstractNote = {Purpose: In respiratory-gated radiation therapy, a baseline shift decreases the accuracy of target coverage and organs at risk (OAR) sparing. The effectiveness of audio-feedback and audio-visual feedback in correcting the baseline shift in the breathing pattern of the patient has been demonstrated previously. However, the baseline shift derived from the intrafraction motion of the patient's body cannot be corrected by these methods. In the present study, the authors designed and developed a simple and flexible system. Methods: The system consisted of a web camera and a computer running our in-house software. The in-house software was adapted to template matching and also to no preimage processing. The system was capable of monitoring the baseline shift in the intrafraction motion of the patient's body. Another marker box was used to monitor the baseline shift due to the flexible setups required of a marker box for gated signals. The system accuracy was evaluated by employing a respiratory motion phantom and was found to be within AAPM Task Group 142 tolerance (positional accuracy <2 mm and temporal accuracy <100 ms) for respiratory-gated radiation therapy. Additionally, the effectiveness of this flexible and independent system in gated treatment was investigated in healthy volunteers, in terms of the results from the differences in the baseline shift detectable between the marker positions, which the authors evaluated statistically. Results: The movement of the marker on the sternum [1.599 {+-} 0.622 mm (1 SD)] was substantially decreased as compared with the abdomen [6.547 {+-} 0.962 mm (1 SD)]. Additionally, in all of the volunteers, the baseline shifts for the sternum [-0.136 {+-} 0.868 (2 SD)] were in better agreement with the nominal baseline shifts than was the case for the abdomen [-0.722 {+-} 1.56 mm (2 SD)]. The baseline shifts could be accurately measured and detected using the monitoring system, which could acquire the movement of the marker on the sternum. The baseline shift-monitoring system with the displacement-based methods for highly accurate respiratory-gated treatments should be used to make most of the displacement-based gating methods. Conclusions: The advent of intensity modulated radiation therapy and volumetric modulated radiation therapy facilitates margin reduction for the planning target volumes and the OARs, but highly accurate irradiation is needed to achieve target coverage and OAR sparing with a small margin. The baseline shifts can affect treatment not only with the respiratory gating system but also without the system. Our system can manage the baseline shift and also enables treatment irradiation to be undertaken with high accuracy.},
doi = {10.1118/1.3598434},
journal = {Medical Physics},
issn = {0094-2405},
number = 7,
volume = 38,
place = {United States},
year = {2011},
month = {7}
}