Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Adaptive radiotherapy in locally advanced head and neck cancer : The importance of reduced margins

Enocson, Hedda LU ; Haraldsson, André LU ; Engström, Per LU ; Ceberg, Sofie LU ; Gebre-Medhin, Maria LU ; Adrian, Gabriel LU orcid and Af Rosenschöld, Per Munck LU orcid (2025) In Physics and imaging in radiation oncology 33.
Abstract

BACKGROUND AND PURPOSE: Adaptive radiotherapy (ART) involves treatment re-planning based on anatomical changes, which may improve target coverage and sparing of organs-at-risk (OARs). This study retrospectively assessed the technical feasibility and potential benefits of daily ART in combination with reduced planning target volume (PTV) margins for head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS: Thirty-one patients, encompassing 902 treatment fractions, treated with radiotherapy to 60.0-68.0 Gy in 2 Gy/fraction were studied. Synthetic CTs (sCT) from daily kVCT images were created and contours propagated using deformable image registration (DIR). Target contours were reviewed and corrected. On the sCT,... (More)

BACKGROUND AND PURPOSE: Adaptive radiotherapy (ART) involves treatment re-planning based on anatomical changes, which may improve target coverage and sparing of organs-at-risk (OARs). This study retrospectively assessed the technical feasibility and potential benefits of daily ART in combination with reduced planning target volume (PTV) margins for head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS: Thirty-one patients, encompassing 902 treatment fractions, treated with radiotherapy to 60.0-68.0 Gy in 2 Gy/fraction were studied. Synthetic CTs (sCT) from daily kVCT images were created and contours propagated using deformable image registration (DIR). Target contours were reviewed and corrected. On the sCT, non-adapted delivered doses and ART-plans with 5 mm (clinical standard) and 2 mm PTV-margin were evaluated. All daily dose distributions were then accumulated.

RESULTS: Target contours required correction in 48 % of the fractions. Daily non-adapted D98%,CTV was > 95 % in 890 (5 mm) and 825 (2 mm) out of 902 fractions. All adapted plans achieved D98%,CTV > 95 %. Significant reductions in mean doses to OARs were observed for PTV = 2 mm ART-plans: 4.1 Gy for parotid, 2.6 Gy for submandibular, 3.3 Gy for oral cavity, 4.0 Gy for esophagus, and 3.8 Gy for larynx.

CONCLUSION: ART-planning on sCT and DIR propagated contours was feasible and promising for further clinical testing. To obtain a potential clinical benefit of ART, a synchronous reduction of the PTV-margin was warranted. Daily ART can be used to maintain adequate target dosimetry for every fraction, though for the accumulated treatment, insufficient target coverage without ART is unlikely to occur.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Adaptive radiotherapy, Head-and-neck cancer, Re-planning, Radiotherapy, Tomotherapy, VMAT, Deformable registration, IGRT
in
Physics and imaging in radiation oncology
volume
33
article number
100696
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85215405373
  • pmid:39897022
ISSN
2405-6316
DOI
10.1016/j.phro.2025.100696
language
English
LU publication?
yes
additional info
© 2025 The Author(s).
id
ce547ef8-2c78-4a64-8a84-156a265a58a9
date added to LUP
2025-02-20 14:02:39
date last changed
2025-07-11 15:50:24
@article{ce547ef8-2c78-4a64-8a84-156a265a58a9,
  abstract     = {{<p>BACKGROUND AND PURPOSE: Adaptive radiotherapy (ART) involves treatment re-planning based on anatomical changes, which may improve target coverage and sparing of organs-at-risk (OARs). This study retrospectively assessed the technical feasibility and potential benefits of daily ART in combination with reduced planning target volume (PTV) margins for head and neck squamous cell carcinoma (HNSCC).</p><p>MATERIALS AND METHODS: Thirty-one patients, encompassing 902 treatment fractions, treated with radiotherapy to 60.0-68.0 Gy in 2 Gy/fraction were studied. Synthetic CTs (sCT) from daily kVCT images were created and contours propagated using deformable image registration (DIR). Target contours were reviewed and corrected. On the sCT, non-adapted delivered doses and ART-plans with 5 mm (clinical standard) and 2 mm PTV-margin were evaluated. All daily dose distributions were then accumulated.</p><p>RESULTS: Target contours required correction in 48 % of the fractions. Daily non-adapted D98%,CTV was &gt; 95 % in 890 (5 mm) and 825 (2 mm) out of 902 fractions. All adapted plans achieved D98%,CTV &gt; 95 %. Significant reductions in mean doses to OARs were observed for PTV = 2 mm ART-plans: 4.1 Gy for parotid, 2.6 Gy for submandibular, 3.3 Gy for oral cavity, 4.0 Gy for esophagus, and 3.8 Gy for larynx.</p><p>CONCLUSION: ART-planning on sCT and DIR propagated contours was feasible and promising for further clinical testing. To obtain a potential clinical benefit of ART, a synchronous reduction of the PTV-margin was warranted. Daily ART can be used to maintain adequate target dosimetry for every fraction, though for the accumulated treatment, insufficient target coverage without ART is unlikely to occur.</p>}},
  author       = {{Enocson, Hedda and Haraldsson, André and Engström, Per and Ceberg, Sofie and Gebre-Medhin, Maria and Adrian, Gabriel and Af Rosenschöld, Per Munck}},
  issn         = {{2405-6316}},
  keywords     = {{Adaptive radiotherapy; Head-and-neck cancer; Re-planning; Radiotherapy; Tomotherapy; VMAT; Deformable registration; IGRT}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Physics and imaging in radiation oncology}},
  title        = {{Adaptive radiotherapy in locally advanced head and neck cancer : The importance of reduced margins}},
  url          = {{http://dx.doi.org/10.1016/j.phro.2025.100696}},
  doi          = {{10.1016/j.phro.2025.100696}},
  volume       = {{33}},
  year         = {{2025}},
}