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Advanced dose calculation algorithms in lung cancer radiotherapy : Implications for SBRT and locally advanced disease in deep inspiration breath hold

Josipovic, Mirjana ; Persson, Gitte Fredberg ; Rydhög, Jonas Scherman ; Smulders, Bob ; Thomsen, Jakob Borup and Aznar, Marianne Camille (2018) In Physica Medica 56. p.50-57
Abstract

Purpose: Evaluating performance of modern dose calculation algorithms in SBRT and locally advanced lung cancer radiotherapy in free breathing (FB) and deep inspiration breath hold (DIBH). Methods: For 17 patients with early stage and 17 with locally advanced lung cancer, a plan in FB and in DIBH were generated with Anisotropic Analytical Algorithm (AAA). Plans for early stage were 3D-conformal SBRT, 45 Gy in 3 fractions, prescribed to 95% isodose covering 95% of PTV and aiming for 140% dose centrally in the tumour. Locally advanced plans were volumetric modulated arc therapy, 66 Gy in 33 fractions, prescribed to mean PTV dose. Calculation grid size was 1 mm for SBRT and 2.5 mm for locally advanced plans. All plans were recalculated with... (More)

Purpose: Evaluating performance of modern dose calculation algorithms in SBRT and locally advanced lung cancer radiotherapy in free breathing (FB) and deep inspiration breath hold (DIBH). Methods: For 17 patients with early stage and 17 with locally advanced lung cancer, a plan in FB and in DIBH were generated with Anisotropic Analytical Algorithm (AAA). Plans for early stage were 3D-conformal SBRT, 45 Gy in 3 fractions, prescribed to 95% isodose covering 95% of PTV and aiming for 140% dose centrally in the tumour. Locally advanced plans were volumetric modulated arc therapy, 66 Gy in 33 fractions, prescribed to mean PTV dose. Calculation grid size was 1 mm for SBRT and 2.5 mm for locally advanced plans. All plans were recalculated with AcurosXB with same MU as in AAA, for comparison on target coverage and dose to risk organs. Results: Lung volume increased in DIBH, resulting in decreased lung density (6% for early and 13% for locally-advanced group). In SBRT, AAA overestimated mean and near-minimum PTV dose (p-values < 0.01) compared to AcurosXB, with largest impact in DIBH (differences of up to 11 Gy). These clinically relevant differences may be a combination of small targets and large dose gradients within the PTV. In locally advanced group, AAA overestimated mean GTV, CTV and PTV doses by median less than 0.8 Gy and near-minimum doses by median 0.4–2.7 Gy. No clinically meaningful difference was observed for lung and heart dose metrics between the algorithms, for both FB and DIBH. Conclusions: AAA overestimated target coverage compared to AcurosXB, especially in DIBH for SBRT.

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author
; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Deep inspiration breath hold, Dose calculation, Lung radiotherapy, SABR, SBRT
in
Physica Medica
volume
56
pages
8 pages
publisher
ISTITUTI EDITORIALI E POLGRAFICI INTERNAZIONALI
external identifiers
  • scopus:85056828764
  • pmid:30527089
ISSN
1120-1797
DOI
10.1016/j.ejmp.2018.11.013
language
English
LU publication?
no
id
8aff88e5-963b-415d-afe3-5ce33da0733f
date added to LUP
2022-03-29 11:21:12
date last changed
2024-05-08 14:18:19
@article{8aff88e5-963b-415d-afe3-5ce33da0733f,
  abstract     = {{<p>Purpose: Evaluating performance of modern dose calculation algorithms in SBRT and locally advanced lung cancer radiotherapy in free breathing (FB) and deep inspiration breath hold (DIBH). Methods: For 17 patients with early stage and 17 with locally advanced lung cancer, a plan in FB and in DIBH were generated with Anisotropic Analytical Algorithm (AAA). Plans for early stage were 3D-conformal SBRT, 45 Gy in 3 fractions, prescribed to 95% isodose covering 95% of PTV and aiming for 140% dose centrally in the tumour. Locally advanced plans were volumetric modulated arc therapy, 66 Gy in 33 fractions, prescribed to mean PTV dose. Calculation grid size was 1 mm for SBRT and 2.5 mm for locally advanced plans. All plans were recalculated with AcurosXB with same MU as in AAA, for comparison on target coverage and dose to risk organs. Results: Lung volume increased in DIBH, resulting in decreased lung density (6% for early and 13% for locally-advanced group). In SBRT, AAA overestimated mean and near-minimum PTV dose (p-values &lt; 0.01) compared to AcurosXB, with largest impact in DIBH (differences of up to 11 Gy). These clinically relevant differences may be a combination of small targets and large dose gradients within the PTV. In locally advanced group, AAA overestimated mean GTV, CTV and PTV doses by median less than 0.8 Gy and near-minimum doses by median 0.4–2.7 Gy. No clinically meaningful difference was observed for lung and heart dose metrics between the algorithms, for both FB and DIBH. Conclusions: AAA overestimated target coverage compared to AcurosXB, especially in DIBH for SBRT.</p>}},
  author       = {{Josipovic, Mirjana and Persson, Gitte Fredberg and Rydhög, Jonas Scherman and Smulders, Bob and Thomsen, Jakob Borup and Aznar, Marianne Camille}},
  issn         = {{1120-1797}},
  keywords     = {{Deep inspiration breath hold; Dose calculation; Lung radiotherapy; SABR; SBRT}},
  language     = {{eng}},
  pages        = {{50--57}},
  publisher    = {{ISTITUTI EDITORIALI E POLGRAFICI INTERNAZIONALI}},
  series       = {{Physica Medica}},
  title        = {{Advanced dose calculation algorithms in lung cancer radiotherapy : Implications for SBRT and locally advanced disease in deep inspiration breath hold}},
  url          = {{http://dx.doi.org/10.1016/j.ejmp.2018.11.013}},
  doi          = {{10.1016/j.ejmp.2018.11.013}},
  volume       = {{56}},
  year         = {{2018}},
}