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Title: Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients

Abstract

Purpose: Hyperthermia is the clinical application of heat, in which tumor temperatures are raised to 40°C to 45°C. This proven radiation and chemosensitizer significantly improves clinical outcome for several tumor sites. Earlier studies of the use of pre-treatment planning for hyperthermia showed good qualitative but disappointing quantitative reliability. The purpose of this study was to investigate whether hyperthermia treatment planning (HTP) can be used more reliably for online adaptive treatment planning during locoregional hyperthermia treatments. Methods and Materials: This study included 78 treatment sessions for 15 patients with non-muscle-invasive bladder cancer. At the start of treatments, temperature rise measurements were performed with 3 different antenna settings optimized for each patient, from which the absorbed power (specific absorption rate [SAR]) was derived. HTP was performed based on a computed tomography (CT) scan in treatment position with the bladder catheter in situ. The SAR along the thermocouple tracks was extracted from the simulated SAR distributions. Correlations between measured and simulated (average) SAR values were determined. To evaluate phase steering, correlations between the changes in simulated and measured SAR values averaged over the thermocouple probe were determined for all 3 combinations of antenna settings. Results: For 42% of the individual treatment sessions, themore » correlation coefficient between measured and simulated SAR profiles was higher than 0.5, whereas 58% showed a weak correlation (R of <0.5). The overall correlation coefficient between measured and simulated average SAR was weak (R=0.31; P<.001). The measured and simulated changes in average SAR after adapting antenna settings correlated much better (R=0.70; P<.001). The ratio between the measured and simulated quotients of maximum and average SARs was 1.03 ± 0.26 (mean ± SD), indicating that HTP can also correctly predict the relative amplitude of SAR peaks. Conclusions: HTP can correctly predict SAR changes after adapting antenna settings during hyperthermia treatments. This allows online adaptive treatment planning, assisting the operator in determining antenna settings resulting in increased tumor temperatures.« less

Authors:
 [1]; ; ; ; ;  [1];  [2]; ;  [1]
  1. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)
  2. Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome (Italy)
Publication Date:
OSTI Identifier:
22423831
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 90; Journal Issue: 2; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ABSORPTION; ANTENNAS; BLADDER; CAT SCANNING; HEAT; HYPERTHERMIA; MUSCLES; NEOPLASMS; PATIENTS; PLANNING; THERMOCOUPLES

Citation Formats

Kok, H. Petra, E-mail: H.P.Kok@amc.uva.nl, Ciampa, Silvia, Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Kroon-Oldenhof, Rianne de, Steggerda-Carvalho, Eva J., Stam, Gerard van, Zum Vörde Sive Vörding, Paul J., Stalpers, Lukas J.A., Geijsen, Elisabeth D., Bardati, Fernando, Bel, Arjan, and Crezee, Johannes. Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients. United States: N. p., 2014. Web. doi:10.1016/J.IJROBP.2014.05.1307.
Kok, H. Petra, E-mail: H.P.Kok@amc.uva.nl, Ciampa, Silvia, Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Kroon-Oldenhof, Rianne de, Steggerda-Carvalho, Eva J., Stam, Gerard van, Zum Vörde Sive Vörding, Paul J., Stalpers, Lukas J.A., Geijsen, Elisabeth D., Bardati, Fernando, Bel, Arjan, & Crezee, Johannes. Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients. United States. doi:10.1016/J.IJROBP.2014.05.1307.
Kok, H. Petra, E-mail: H.P.Kok@amc.uva.nl, Ciampa, Silvia, Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Kroon-Oldenhof, Rianne de, Steggerda-Carvalho, Eva J., Stam, Gerard van, Zum Vörde Sive Vörding, Paul J., Stalpers, Lukas J.A., Geijsen, Elisabeth D., Bardati, Fernando, Bel, Arjan, and Crezee, Johannes. Wed . "Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients". United States. doi:10.1016/J.IJROBP.2014.05.1307.
@article{osti_22423831,
title = {Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients},
author = {Kok, H. Petra, E-mail: H.P.Kok@amc.uva.nl and Ciampa, Silvia and Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome and Kroon-Oldenhof, Rianne de and Steggerda-Carvalho, Eva J. and Stam, Gerard van and Zum Vörde Sive Vörding, Paul J. and Stalpers, Lukas J.A. and Geijsen, Elisabeth D. and Bardati, Fernando and Bel, Arjan and Crezee, Johannes},
abstractNote = {Purpose: Hyperthermia is the clinical application of heat, in which tumor temperatures are raised to 40°C to 45°C. This proven radiation and chemosensitizer significantly improves clinical outcome for several tumor sites. Earlier studies of the use of pre-treatment planning for hyperthermia showed good qualitative but disappointing quantitative reliability. The purpose of this study was to investigate whether hyperthermia treatment planning (HTP) can be used more reliably for online adaptive treatment planning during locoregional hyperthermia treatments. Methods and Materials: This study included 78 treatment sessions for 15 patients with non-muscle-invasive bladder cancer. At the start of treatments, temperature rise measurements were performed with 3 different antenna settings optimized for each patient, from which the absorbed power (specific absorption rate [SAR]) was derived. HTP was performed based on a computed tomography (CT) scan in treatment position with the bladder catheter in situ. The SAR along the thermocouple tracks was extracted from the simulated SAR distributions. Correlations between measured and simulated (average) SAR values were determined. To evaluate phase steering, correlations between the changes in simulated and measured SAR values averaged over the thermocouple probe were determined for all 3 combinations of antenna settings. Results: For 42% of the individual treatment sessions, the correlation coefficient between measured and simulated SAR profiles was higher than 0.5, whereas 58% showed a weak correlation (R of <0.5). The overall correlation coefficient between measured and simulated average SAR was weak (R=0.31; P<.001). The measured and simulated changes in average SAR after adapting antenna settings correlated much better (R=0.70; P<.001). The ratio between the measured and simulated quotients of maximum and average SARs was 1.03 ± 0.26 (mean ± SD), indicating that HTP can also correctly predict the relative amplitude of SAR peaks. Conclusions: HTP can correctly predict SAR changes after adapting antenna settings during hyperthermia treatments. This allows online adaptive treatment planning, assisting the operator in determining antenna settings resulting in increased tumor temperatures.},
doi = {10.1016/J.IJROBP.2014.05.1307},
journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 2,
volume = 90,
place = {United States},
year = {2014},
month = {10}
}