3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom

In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX™ container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated treatment concepts in adaptive radiotherapy.

[1]  D. Marquardt.  An Algorithm for Least-Squares Estimation of Nonlinear Parameters , 1963 .

[2]  John F. Canny,et al.  A Computational Approach to Edge Detection , 1986, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[3]  L. Rudin,et al.  Nonlinear total variation based noise removal algorithms , 1992 .

[4]  Icru.  Prescribing, recording, and reporting photon beam therapy , 1993 .

[5]  H. Kubo,et al.  Respiration gated radiotherapy treatment: a technical study. , 1996, Physics in medicine and biology.

[6]  D. Low,et al.  A technique for the quantitative evaluation of dose distributions. , 1998, Medical physics.

[7]  J. Dempsey,et al.  Evaluation of polymer gels and MRI as a 3-D dosimeter for intensity-modulated radiation therapy. , 1999, Medical physics.

[8]  C Baldock,et al.  A basic study of some normoxic polymer gel dosimeters. , 2002, Physics in medicine and biology.

[9]  Lars E Olsson,et al.  MAGIC-type polymer gel for three-dimensional dosimetry: intensity-modulated radiation therapy verification. , 2003, Medical physics.

[10]  R. Mohan,et al.  Acquiring a four-dimensional computed tomography dataset using an external respiratory signal. , 2003, Physics in medicine and biology.

[11]  Jürgen Biederer,et al.  Artificial thorax for MR imaging studies in porcine heart-lung preparations. , 2003, Radiology.

[12]  L. Sakelliou,et al.  Dose verification in clinical IMRT prostate incidents. , 2004, International journal of radiation oncology, biology, physics.

[13]  Hans-Ulrich Kauczor,et al.  Measurement of tumor diameter-dependent mobility of lung tumors by dynamic MRI. , 2004, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[14]  Y. D. Deene,et al.  Validation and application of polymer gel dosimetry for the dose verification of an intensity-modulated arc therapy (IMAT) treatment. , 2004, Physics in medicine and biology.

[15]  George T. Y. Chen,et al.  A phantom evaluation of a stereo-vision surface imaging system for radiotherapy patient setup. , 2005, Medical physics.

[16]  C Baldock,et al.  Investigation of the PAGAT polymer gel dosimeter using magnetic resonance imaging , 2005, Physics in medicine and biology.

[17]  Steve B. Jiang,et al.  The management of respiratory motion in radiation oncology report of AAPM Task Group 76. , 2006, Medical physics.

[18]  M. Oldham,et al.  IMRT verification using a radiochromic/optical-CT dosimetry system. , 2006, Journal of physics. Conference series.

[19]  Christoph Bert,et al.  Clinical experience with a 3D surface patient setup system for alignment of partial-breast irradiation patients. , 2006, International journal of radiation oncology, biology, physics.

[20]  C De Wagter,et al.  The fundamental radiation properties of normoxic polymer gel dosimeters: a comparison between a methacrylic acid based gel and acrylamide based gels , 2006, Physics in medicine and biology.

[21]  L. Schreiner.  Dosimetry in modern radiation therapy: limitations and needs , 2006 .

[22]  Steve B. Jiang,et al.  Technical aspects of image-guided respiration-gated radiation therapy. , 2006, Medical dosimetry : official journal of the American Association of Medical Dosimetrists.

[23]  K. McAuley,et al.  Dose integration characteristics in normoxic polymer gel dosimetry investigated using sequential beam irradiation , 2007, Physics in medicine and biology.

[24]  Y. De Deene,et al.  The influence of cooling rate on the accuracy of normoxic polymer gel dosimeters , 2007, Physics in medicine and biology.

[25]  Steve B. Jiang,et al.  Multiple template-based fluoroscopic tracking of lung tumor mass without implanted fiducial markers , 2007, Physics in medicine and biology.

[26]  Steve B. Jiang,et al.  Fluoroscopic tracking of multiple implanted fiducial markers using multiple object tracking , 2007, Physics in medicine and biology.

[27]  P. Jursinic,et al.  Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements. , 2007, Medical physics.

[28]  S Nill,et al.  Detection of respiratory motion in fluoroscopic images for adaptive radiotherapy , 2008, Physics in medicine and biology.

[29]  H Gustavsson,et al.  Verification of dynamic radiotherapy: the potential for 3D dosimetry under respiratory-like motion using polymer gel , 2008, Physics in medicine and biology.

[30]  Michael Bock,et al.  4D-Imaging of the lung: reproducibility of lesion size and displacement on helical CT, MRI, and cone beam CT in a ventilated ex vivo system. , 2009, International journal of radiation oncology, biology, physics.

[31]  G. Qiao,et al.  Small field size dose-profile measurements using gel dosimeters, gafchromic films and micro-thermoluminescent dosimeters , 2009 .

[32]  K. McAuley,et al.  Preliminary investigation of the NMR, optical and x-ray CT dose–response of polymer gel dosimeters incorporating cosolvents to improve dose sensitivity , 2009, Physics in medicine and biology.

[33]  M. Oldham,et al.  Polymer gel dosimetry. , 2010, Physics in medicine and biology.

[34]  Uwe Oelfke,et al.  Real-time tumor tracking: automatic compensation of target motion using the Siemens 160 MLC. , 2010, Medical physics.

[35]  M. Oldham,et al.  Investigation into the feasibility of using PRESAGE™/optical-CT dosimetry for the verification of gating treatments , 2010, Physics in medicine and biology.

[36]  Mark Oldham,et al.  Toward acquiring comprehensive radiosurgery field commissioning data using the PRESAGE®/ optical-CT 3D dosimetry system , 2010, Physics in medicine and biology.

[38]  Ross Berbeco,et al.  Use of a realistic breathing lung phantom to evaluate dose delivery errorsa). , 2010, Medical physics.

[39]  P Rassiah-Szegedi,et al.  A proto-type design of a real-tissue phantom for the validation of deformation algorithms and 4D dose calculations. , 2010, Physics in medicine and biology.

[40]  Accurate calibration of a polymer gel dosimeter with a plastic scintillation detector. , 2011, Medical physics.

[41]  S. Korreman.  Motion in radiotherapy: photon therapy , 2012, Physics in medicine and biology.

[42]  A C Vásquez,et al.  Comparison of two respiration monitoring systems for 4D imaging with a Siemens CT using a new dynamic breathing phantom , 2012, Physics in medicine and biology.

[43]  SU-E-J-147: Dosimetric Consequences of Intrafraction Prostate Motion: Comparison Between Phantom Measurements and Three Different Calculation Methods. , 2012, Medical physics.

[44]  Yves De Deene,et al.  On the validity of 3D polymer gel dosimetry: I. Reproducibility study , 2013, Physics in medicine and biology.

[45]  Yves De Deene,et al.  On the validity of 3D polymer gel dosimetry: II. Physico-chemical effects , 2013, Physics in medicine and biology.

[46]  Klaus H. Maier-Hein,et al.  The Medical Imaging Interaction Toolkit: challenges and advances , 2013, International Journal of Computer Assisted Radiology and Surgery.

[47]  Y. De Deene,et al.  Evaluation of radiochromic gel dosimetry and polymer gel dosimetry in a clinical dose verification , 2013, Physics in medicine and biology.

[48]  Feasibility of polymer gel dosimetry measurements in a dynamic porcine lung phantom , 2015 .

[49]  Peter Bachert,et al.  Simultaneous mapping of water shift and B1(WASABI)—Application to field‐Inhomogeneity correction of CEST MRI data , 2017, Magnetic resonance in medicine.