Dosimetric predictors of toxicity in a randomized study of short-course vs conventional radiotherapy for glioblastoma.

Autor: Yang F; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Dinakaran D; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Heikal AA; Division of Medical Physics, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Yaghoobpour Tari S; Division of Medical Physics, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Ghosh S; Division of Medical Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Amanie J; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Murtha A; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Rowe LS; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Roa WH; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada., Patel S; Division of Radiation Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada. Electronic address: samir.patel2@albertahealthservices.ca.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2022 Dec; Vol. 177, pp. 152-157. Date of Electronic Publication: 2022 Oct 20.
DOI: 10.1016/j.radonc.2022.10.016
Abstrakt: Purpose: There is no consensus on appropriate organ at risk (OAR) constraints for short-course radiotherapy for patients with glioblastoma. Using dosimetry and prospectively-collected toxicity data from a trial of short-course radiotherapy for glioblastoma, this study aims to empirically examine the OAR constraints, with particular attention to left hippocampus dosimetry and impact on neuro-cognitive decline.
Methods and Materials: Data was taken from a randomized control trial of 133 adults (age 18-70 years; ECOG performance score 0-2) with newly diagnosed glioblastoma treated with 60 Gy in 30 (conventional arm) versus 20 (short-course arm) fractions of adjuvant chemoradiotherapy (ClinicalTrials.gov Identifier: NCT02206230). The delivered plan's dosimetry to the OARs was correlated to prospective-collected toxicity and Mini-Mental State Examination (MMSE) data.
Results: Toxicity events were not significantly increased in the short-course arm versus the conventional arm. Across all OARs, delivered radiation doses within protocol-allowable maximum doses correlated with lack of grade ≥ 2 toxicities in both arms (p < 0.001), while patients with OAR doses at or above protocol limits correlated with increased grade ≥ 2 toxicities across all examined OARs in both arms (p-values 0.063-0.250). Mean left hippocampus dose was significantly associated with post-radiotherapy decline in MMSE scores (p = 0.005), while the right hippocampus mean dose did not reach statistical significance (p = 0.277). Compared to the original clinical plan, RapidPlan left hippocampus sparing model decreased left hippocampus mean dose by 43 % (p < 0.001), without compromising planning target volume coverage.
Conclusions: In this trial, protocol OAR constraints were appropriate for limiting grade ≥ 2 toxicities in conventional and short-course adjuvant chemoradiotherapy for glioblastoma. Higher left hippocampal mean doses were predictive for neuro-cognitive decline post-radiotherapy. Routine contouring and use of dose constraints to limit hippocampal dose is recommended to minimize neuro-cognitive decline in patients with glioblastoma treated with chemoradiotherapy.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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