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A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer

Rosenschöld, Per Munck Af LU orcid ; Aznar, Marianne C. ; Nygaard, Ditte E. ; Persson, Gitte F. ; Korreman, Stine S. ; Engelholm, Svend Aage and Nyström, Hkan (2010) In Acta Oncologica 49(7). p.1141-1148
Abstract

Background. Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour motion. Material and methods. Seven patients with a nine targets with 4DCT scans were selected. IMPT plans were made on the midventilation phase using a 3-field technique. The plans were transferred and calculated on the remaining nine phases of the 4DCT, and the combined dose distribution was summed using deformable image registration (DIR). An additional set of plans were made in which the proton beam was simply geometrically shifted... (More)

Background. Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour motion. Material and methods. Seven patients with a nine targets with 4DCT scans were selected. IMPT plans were made on the midventilation phase using a 3-field technique. The plans were transferred and calculated on the remaining nine phases of the 4DCT, and the combined dose distribution was summed using deformable image registration (DIR). An additional set of plans were made in which the proton beam was simply geometrically shifted to the centre of the gross tumour volume (GTV), i.e. simulating tracking of the tumour motion but without on-line adjustment of the proton energies. A possible interplay effect between the dynamics of the spot scanning delivery and the tumour motion has not been considered in this work. Results. Around 97-100% of the GTV was covered by 95% of the prescribed dose (V95) for a tumour displacement of less than about 1 cm with a static beam. For the remaining three of nine targets with a larger motion the tracking method studied provided a marked improvement over static beam; raising the GTV V95 from 95 to 100%, 82 to 98% and 51 to 97%, respectively. Conclusion. The possibility of performing DIR and summing the dose on the 4DCT data set was shown to be feasible. The fairly simplistic tracking method suggested here resulted in a marked improvement in GTV coverage for tumours with large intra-fractional motion (>1 cm displacement), indicating that on-line adjustment of the proton energies may be redundant.

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author
; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta Oncologica
volume
49
issue
7
pages
1141 - 1148
publisher
Taylor & Francis
external identifiers
  • pmid:20831506
  • scopus:77956607783
ISSN
0284-186X
DOI
10.3109/0284186X.2010.500620
language
English
LU publication?
no
additional info
Funding Information: Mr. Thomas Carlslund and Mr. Mikael Olsen are acknowledged for technical support. Mr. Richard diMonda (Velocity Medical Systems, USA) and Dr. Tim Fox (Emory University Hospital, Atlanta, USA) are acknowledged for valuable discussions. Stine Korreman and Ditte E. Nygaard thank the Lundbeck foundation for financial support.
id
b112e56f-d5aa-4a23-a75a-c121481affe3
date added to LUP
2023-07-19 17:14:18
date last changed
2024-01-05 03:35:54
@article{b112e56f-d5aa-4a23-a75a-c121481affe3,
  abstract     = {{<p>Background. Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour motion. Material and methods. Seven patients with a nine targets with 4DCT scans were selected. IMPT plans were made on the midventilation phase using a 3-field technique. The plans were transferred and calculated on the remaining nine phases of the 4DCT, and the combined dose distribution was summed using deformable image registration (DIR). An additional set of plans were made in which the proton beam was simply geometrically shifted to the centre of the gross tumour volume (GTV), i.e. simulating tracking of the tumour motion but without on-line adjustment of the proton energies. A possible interplay effect between the dynamics of the spot scanning delivery and the tumour motion has not been considered in this work. Results. Around 97-100% of the GTV was covered by 95% of the prescribed dose (V95) for a tumour displacement of less than about 1 cm with a static beam. For the remaining three of nine targets with a larger motion the tracking method studied provided a marked improvement over static beam; raising the GTV V95 from 95 to 100%, 82 to 98% and 51 to 97%, respectively. Conclusion. The possibility of performing DIR and summing the dose on the 4DCT data set was shown to be feasible. The fairly simplistic tracking method suggested here resulted in a marked improvement in GTV coverage for tumours with large intra-fractional motion (&gt;1 cm displacement), indicating that on-line adjustment of the proton energies may be redundant.</p>}},
  author       = {{Rosenschöld, Per Munck Af and Aznar, Marianne C. and Nygaard, Ditte E. and Persson, Gitte F. and Korreman, Stine S. and Engelholm, Svend Aage and Nyström, Hkan}},
  issn         = {{0284-186X}},
  language     = {{eng}},
  number       = {{7}},
  pages        = {{1141--1148}},
  publisher    = {{Taylor & Francis}},
  series       = {{Acta Oncologica}},
  title        = {{A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer}},
  url          = {{http://dx.doi.org/10.3109/0284186X.2010.500620}},
  doi          = {{10.3109/0284186X.2010.500620}},
  volume       = {{49}},
  year         = {{2010}},
}