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Gamma Knife radiosurgery with CT image‐based dose calculation

The Leksell GammaPlan software version 10 introduces a CT image‐based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gam...

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Autores principales: Xu, Andy (Yuanguang), Bhatnagar, Jagdish, Bednarz, Greg, Niranjan, Ajay, Kondziolka, Douglas, Flickinger, John, Lunsford, L. Dade, Huq, M. Saiful
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5691031/
https://www.ncbi.nlm.nih.gov/pubmed/26699563
http://dx.doi.org/10.1120/jacmp.v16i6.5530
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author Xu, Andy (Yuanguang)
Bhatnagar, Jagdish
Bednarz, Greg
Niranjan, Ajay
Kondziolka, Douglas
Flickinger, John
Lunsford, L. Dade
Huq, M. Saiful
author_facet Xu, Andy (Yuanguang)
Bhatnagar, Jagdish
Bednarz, Greg
Niranjan, Ajay
Kondziolka, Douglas
Flickinger, John
Lunsford, L. Dade
Huq, M. Saiful
author_sort Xu, Andy (Yuanguang)
collection PubMed
description The Leksell GammaPlan software version 10 introduces a CT image‐based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gamma Knife treatment planning. Sixty‐five patients who underwent CT image‐guided Gamma Knife radiosurgeries at the University of Pittsburgh Medical Center in recent years were retrospectively investigated. The diagnoses for these cases include trigeminal neuralgia, meningioma, acoustic neuroma, AVM, glioma, and benign and metastatic brain tumors. Dose calculations were performed for each patient with the same dose prescriptions and the same shot arrangements using three different approaches: 1) TMR 10 dose calculation with imaging skull definition; 2) convolution dose calculation with imaging skull definition; 3) TMR 10 dose calculation with conventional measurement‐based skull definition. For each treatment matrix, the total treatment time, the target coverage index, the selectivity index, the gradient index, and a set of dose statistics parameters were compared between the three calculations. The dose statistics parameters investigated include the prescription isodose volume, the 12 Gy isodose volume, the minimum, maximum and mean doses on the treatment targets, and the critical structures under consideration. The difference between the convolution and the TMR 10 dose calculations for the 104 treatment matrices were found to vary with the patient anatomy, location of the treatment shots, and the tissue inhomogeneities around the treatment target. An average difference of 8.4% was observed for the total treatment times between the convolution and the TMR algorithms. The maximum differences in the treatment times, the prescription isodose volumes, the 12 Gy isodose volumes, the target coverage indices, the selectivity indices, and the gradient indices from the convolution and the TMR 10 calculations are 14.9%, 16.4%, 11.1%, 16.8, 6.9%, and 11.4%, respectively. The maximum differences in the minimum and the mean target doses between the two calculation algorithms are 8.1% and 4.2% of the corresponding prescription doses. The maximum differences in the maximum and the mean doses for the critical structures between the two calculation algorithms are 1.3 Gy and 0.7 Gy. The results from the two skull definition methods with the TMR 10 algorithm agree either within [Formula: see text] or 0.3 Gy for the dose values, except for a 4.9% difference in the treatment times for a lower cerebellar lesion. The imaging skull definition method does not affect Gamma Knife dose calculation considerably when compared to the conventional measurement‐based skull definition method, except in some extreme cases. Large differences were observed between the TMR 10 and the convolution calculation method for the same dose prescription and the same shot arrangements, indicating that the implementation of the convolution algorithm in routine clinical use might be desirable for optimal dose calculation results. PACS numbers: 87.55.D, 87.55.kd
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spelling pubmed-56910312018-04-02 Gamma Knife radiosurgery with CT image‐based dose calculation Xu, Andy (Yuanguang) Bhatnagar, Jagdish Bednarz, Greg Niranjan, Ajay Kondziolka, Douglas Flickinger, John Lunsford, L. Dade Huq, M. Saiful J Appl Clin Med Phys Radiation Oncology Physics The Leksell GammaPlan software version 10 introduces a CT image‐based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gamma Knife treatment planning. Sixty‐five patients who underwent CT image‐guided Gamma Knife radiosurgeries at the University of Pittsburgh Medical Center in recent years were retrospectively investigated. The diagnoses for these cases include trigeminal neuralgia, meningioma, acoustic neuroma, AVM, glioma, and benign and metastatic brain tumors. Dose calculations were performed for each patient with the same dose prescriptions and the same shot arrangements using three different approaches: 1) TMR 10 dose calculation with imaging skull definition; 2) convolution dose calculation with imaging skull definition; 3) TMR 10 dose calculation with conventional measurement‐based skull definition. For each treatment matrix, the total treatment time, the target coverage index, the selectivity index, the gradient index, and a set of dose statistics parameters were compared between the three calculations. The dose statistics parameters investigated include the prescription isodose volume, the 12 Gy isodose volume, the minimum, maximum and mean doses on the treatment targets, and the critical structures under consideration. The difference between the convolution and the TMR 10 dose calculations for the 104 treatment matrices were found to vary with the patient anatomy, location of the treatment shots, and the tissue inhomogeneities around the treatment target. An average difference of 8.4% was observed for the total treatment times between the convolution and the TMR algorithms. The maximum differences in the treatment times, the prescription isodose volumes, the 12 Gy isodose volumes, the target coverage indices, the selectivity indices, and the gradient indices from the convolution and the TMR 10 calculations are 14.9%, 16.4%, 11.1%, 16.8, 6.9%, and 11.4%, respectively. The maximum differences in the minimum and the mean target doses between the two calculation algorithms are 8.1% and 4.2% of the corresponding prescription doses. The maximum differences in the maximum and the mean doses for the critical structures between the two calculation algorithms are 1.3 Gy and 0.7 Gy. The results from the two skull definition methods with the TMR 10 algorithm agree either within [Formula: see text] or 0.3 Gy for the dose values, except for a 4.9% difference in the treatment times for a lower cerebellar lesion. The imaging skull definition method does not affect Gamma Knife dose calculation considerably when compared to the conventional measurement‐based skull definition method, except in some extreme cases. Large differences were observed between the TMR 10 and the convolution calculation method for the same dose prescription and the same shot arrangements, indicating that the implementation of the convolution algorithm in routine clinical use might be desirable for optimal dose calculation results. PACS numbers: 87.55.D, 87.55.kd John Wiley and Sons Inc. 2015-11-08 /pmc/articles/PMC5691031/ /pubmed/26699563 http://dx.doi.org/10.1120/jacmp.v16i6.5530 Text en © 2015 The Authors. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/3.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Radiation Oncology Physics
Xu, Andy (Yuanguang)
Bhatnagar, Jagdish
Bednarz, Greg
Niranjan, Ajay
Kondziolka, Douglas
Flickinger, John
Lunsford, L. Dade
Huq, M. Saiful
Gamma Knife radiosurgery with CT image‐based dose calculation
title Gamma Knife radiosurgery with CT image‐based dose calculation
title_full Gamma Knife radiosurgery with CT image‐based dose calculation
title_fullStr Gamma Knife radiosurgery with CT image‐based dose calculation
title_full_unstemmed Gamma Knife radiosurgery with CT image‐based dose calculation
title_short Gamma Knife radiosurgery with CT image‐based dose calculation
title_sort gamma knife radiosurgery with ct image‐based dose calculation
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5691031/
https://www.ncbi.nlm.nih.gov/pubmed/26699563
http://dx.doi.org/10.1120/jacmp.v16i6.5530
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