Daily adaptive radiotherapy in head and neck squamous cell carcinoma can negatively impact organ at risk dosimetry
Enocson, Hedda LU ; Haraldsson, André LU ; Engström, Per LU ; Ceberg, Sofie LU ; Gebre-Medhin, Maria LU ; Adrian, Gabriel LU
and af Rosenschöld, Per Munck
LU
(2026)
In Clinical and Translational Radiation Oncology
59.
- Abstract
Purpose: Adaptive radiotherapy (ART) accounts for anatomical changes during treatment and may improve target coverage and spare organs-at-risk (OARs) in head and neck squamous cell carcinoma (HNSCC). This study aimed to develop a protocol defining dose evaluation criteria for target volumes and OARs to assess the need for ART. The protocol was applied to compare compliance between daily-ART and non-ART plans with varying CTV-PTV-margins. Materials and methods: A protocol defining dose criteria for target and OAR volumes was developed and used to evaluate ART in a retrospective cohort of 80 patients (2,170 fractions) treated with radiotherapy to 60.0–68.0 Gy (2 Gy/fraction). Synthetic CTs were generated from daily kVCTs and contours... (More)
Purpose: Adaptive radiotherapy (ART) accounts for anatomical changes during treatment and may improve target coverage and spare organs-at-risk (OARs) in head and neck squamous cell carcinoma (HNSCC). This study aimed to develop a protocol defining dose evaluation criteria for target volumes and OARs to assess the need for ART. The protocol was applied to compare compliance between daily-ART and non-ART plans with varying CTV-PTV-margins. Materials and methods: A protocol defining dose criteria for target and OAR volumes was developed and used to evaluate ART in a retrospective cohort of 80 patients (2,170 fractions) treated with radiotherapy to 60.0–68.0 Gy (2 Gy/fraction). Synthetic CTs were generated from daily kVCTs and contours propagated using deformable image registration. Delivered doses (no-ART) and daily-ART treatments using 5 mm and 2 mm PTV plans were simulated. All daily distributions were evaluated using the protocol. Results: With 2 mm margins, daily-ART significantly reduced protocol violations compared to no-ART(7% vs 20.3%, p < 0.001), while no significant difference was observed with 5 mm margins(15.1% vs 17.3%, p > 0.8). For 2 mm margins, daily-ART resolved 610 violations but introduced 152 new violations. With 5 mm margins, 391 violations were resolved, while 472 violations were introduced. When adaptation was limited to fractions that initially presented violations, fewer new violations were introduced (2 mm: 60; 5 mm: 49). Conclusion: Daily-ART with 2 mm margins improved target coverage and reduced protocol violations, while larger margins increased OAR doses by enforcing full PTV coverage. Restricting daily ART to fractions with identified violations minimized the occurrence of newly introduced violations.
(Less)
- author
- Enocson, Hedda
LU
; Haraldsson, André
LU
; Engström, Per
LU
; Ceberg, Sofie
LU
; Gebre-Medhin, Maria
LU
; Adrian, Gabriel
LU
and af Rosenschöld, Per Munck
LU
- organization
- publishing date
- 2026-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Adaptive radiotherapy, Dose tracking, Head and neck cancer, Protocol-driven adaptation
- in
- Clinical and Translational Radiation Oncology
- volume
- 59
- article number
- 101205
- publisher
- Elsevier
- external identifiers
-
- scopus:105040780679
- pmid:42281957
- ISSN
- 2405-6308
- DOI
- 10.1016/j.ctro.2026.101205
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 Published by Elsevier B.V. on behalf of European Society for Radiotherapy and Oncology. This is an open access article under the CC BY-NC-ND license. http://creativecommons.org/licenses/by-nc-nd/4.0/
- id
- 55e6fd49-3ebd-446c-b542-1589b3c4faa3
- date added to LUP
- 2026-07-21 14:37:15
- date last changed
- 2026-08-04 15:01:26
@article{55e6fd49-3ebd-446c-b542-1589b3c4faa3,
abstract = {{<p>Purpose: Adaptive radiotherapy (ART) accounts for anatomical changes during treatment and may improve target coverage and spare organs-at-risk (OARs) in head and neck squamous cell carcinoma (HNSCC). This study aimed to develop a protocol defining dose evaluation criteria for target volumes and OARs to assess the need for ART. The protocol was applied to compare compliance between daily-ART and non-ART plans with varying CTV-PTV-margins. Materials and methods: A protocol defining dose criteria for target and OAR volumes was developed and used to evaluate ART in a retrospective cohort of 80 patients (2,170 fractions) treated with radiotherapy to 60.0–68.0 Gy (2 Gy/fraction). Synthetic CTs were generated from daily kVCTs and contours propagated using deformable image registration. Delivered doses (no-ART) and daily-ART treatments using 5 mm and 2 mm PTV plans were simulated. All daily distributions were evaluated using the protocol. Results: With 2 mm margins, daily-ART significantly reduced protocol violations compared to no-ART(7% vs 20.3%, p < 0.001), while no significant difference was observed with 5 mm margins(15.1% vs 17.3%, p > 0.8). For 2 mm margins, daily-ART resolved 610 violations but introduced 152 new violations. With 5 mm margins, 391 violations were resolved, while 472 violations were introduced. When adaptation was limited to fractions that initially presented violations, fewer new violations were introduced (2 mm: 60; 5 mm: 49). Conclusion: Daily-ART with 2 mm margins improved target coverage and reduced protocol violations, while larger margins increased OAR doses by enforcing full PTV coverage. Restricting daily ART to fractions with identified violations minimized the occurrence of newly introduced violations.</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 = {{2405-6308}},
keywords = {{Adaptive radiotherapy; Dose tracking; Head and neck cancer; Protocol-driven adaptation}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Clinical and Translational Radiation Oncology}},
title = {{Daily adaptive radiotherapy in head and neck squamous cell carcinoma can negatively impact organ at risk dosimetry}},
url = {{http://dx.doi.org/10.1016/j.ctro.2026.101205}},
doi = {{10.1016/j.ctro.2026.101205}},
volume = {{59}},
year = {{2026}},
}