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The risk of radiation-induced neurocognitive impairment and the impact of sparing the hippocampus during pediatric proton cranial irradiation

Gram, Daniel ; Brodin, N. Patrik ; Björk-Eriksson, Thomas ; Nysom, Karsten and Munck af Rosenschöld, Per LU orcid (2023) In Acta Oncologica 62(2). p.134-140
Abstract

Background and purpose: Hippocampus is a central component for neurocognitive function and memory. We investigated the predicted risk of neurocognitive impairment of craniospinal irradiation (CSI) and the deliverability and effects of hippocampal sparing. The risk estimates were derived from published NTCP models. Specifically, we leveraged the estimated benefit of reduced neurocognitive impairment with the risk of reduced tumor control. Material and methods: For this dose planning study, a total of 504 hippocampal sparing intensity modulated proton therapy (HS-IMPT) plans were generated for 24 pediatric patients whom had previously received CSI. Plans were evaluated with respect to target coverage and homogeneity index to target... (More)

Background and purpose: Hippocampus is a central component for neurocognitive function and memory. We investigated the predicted risk of neurocognitive impairment of craniospinal irradiation (CSI) and the deliverability and effects of hippocampal sparing. The risk estimates were derived from published NTCP models. Specifically, we leveraged the estimated benefit of reduced neurocognitive impairment with the risk of reduced tumor control. Material and methods: For this dose planning study, a total of 504 hippocampal sparing intensity modulated proton therapy (HS-IMPT) plans were generated for 24 pediatric patients whom had previously received CSI. Plans were evaluated with respect to target coverage and homogeneity index to target volumes, maximum and mean dose to OARs. Paired t-tests were used to compare hippocampal mean doses and normal tissue complication probability estimates. Results: The median mean dose to the hippocampus could be reduced from 31.3 GyRBE to 7.3 GyRBE (p <.001), though 20% of these plans were not considered clinically acceptable as they failed one or more acceptance criterion. Reducing the median mean hippocampus dose to 10.6 GyRBE was possible with all plans considered as clinically acceptable treatment plans. By sparing the hippocampus to the lowest dose level, the risk estimation of neurocognitive impairment could be reduced from 89.6%, 62.1% and 51.1% to 41.0% (p <.001), 20.1% (p <.001) and 29.9% (p <.001) for task efficiency, organization and memory, respectively. Estimated tumor control probability was not adversely affected by HS-IMPT, ranging from 78.5 to 80.5% for all plans. Conclusions: We present estimates of potential clinical benefit in terms of neurocognitive impairment and demonstrate the possibility of considerably reducing neurocognitive adverse effects, minimally compromising target coverage locally using HS-IMPT.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
craniospinal irradiation, hippocampal avoidance, Neurocognitive impairment, normal tissue complication probability, pediatric hippocampus, tumor control probability
in
Acta Oncologica
volume
62
issue
2
pages
134 - 140
publisher
Taylor & Francis
external identifiers
  • pmid:36847433
  • scopus:85149322038
ISSN
0284-186X
DOI
10.1080/0284186X.2023.2176253
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2023 Acta Oncologica Foundation.
id
32f7bdeb-1e49-4b68-9115-465daba47e9e
date added to LUP
2023-07-19 09:36:08
date last changed
2024-04-19 23:37:47
@article{32f7bdeb-1e49-4b68-9115-465daba47e9e,
  abstract     = {{<p>Background and purpose: Hippocampus is a central component for neurocognitive function and memory. We investigated the predicted risk of neurocognitive impairment of craniospinal irradiation (CSI) and the deliverability and effects of hippocampal sparing. The risk estimates were derived from published NTCP models. Specifically, we leveraged the estimated benefit of reduced neurocognitive impairment with the risk of reduced tumor control. Material and methods: For this dose planning study, a total of 504 hippocampal sparing intensity modulated proton therapy (HS-IMPT) plans were generated for 24 pediatric patients whom had previously received CSI. Plans were evaluated with respect to target coverage and homogeneity index to target volumes, maximum and mean dose to OARs. Paired t-tests were used to compare hippocampal mean doses and normal tissue complication probability estimates. Results: The median mean dose to the hippocampus could be reduced from 31.3 Gy<sub>RBE</sub> to 7.3 Gy<sub>RBE</sub> (p &lt;.001), though 20% of these plans were not considered clinically acceptable as they failed one or more acceptance criterion. Reducing the median mean hippocampus dose to 10.6 Gy<sub>RBE</sub> was possible with all plans considered as clinically acceptable treatment plans. By sparing the hippocampus to the lowest dose level, the risk estimation of neurocognitive impairment could be reduced from 89.6%, 62.1% and 51.1% to 41.0% (p &lt;.001), 20.1% (p &lt;.001) and 29.9% (p &lt;.001) for task efficiency, organization and memory, respectively. Estimated tumor control probability was not adversely affected by HS-IMPT, ranging from 78.5 to 80.5% for all plans. Conclusions: We present estimates of potential clinical benefit in terms of neurocognitive impairment and demonstrate the possibility of considerably reducing neurocognitive adverse effects, minimally compromising target coverage locally using HS-IMPT.</p>}},
  author       = {{Gram, Daniel and Brodin, N. Patrik and Björk-Eriksson, Thomas and Nysom, Karsten and Munck af Rosenschöld, Per}},
  issn         = {{0284-186X}},
  keywords     = {{craniospinal irradiation; hippocampal avoidance; Neurocognitive impairment; normal tissue complication probability; pediatric hippocampus; tumor control probability}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{134--140}},
  publisher    = {{Taylor & Francis}},
  series       = {{Acta Oncologica}},
  title        = {{The risk of radiation-induced neurocognitive impairment and the impact of sparing the hippocampus during pediatric proton cranial irradiation}},
  url          = {{http://dx.doi.org/10.1080/0284186X.2023.2176253}},
  doi          = {{10.1080/0284186X.2023.2176253}},
  volume       = {{62}},
  year         = {{2023}},
}