Fischer, Christian, Seidlitz, Annekatrin, Krause, Mechthild · Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al] · 2026 · DOI
This is a single case report of a 46-year-old woman with ME/CFS whose condition severely worsened after receiving proton beam radiation therapy for a brain tumor. Over months following treatment, she went from being ambulatory to completely bedridden, with worsening fatigue, pain, dizziness, and cognitive problems. The report suggests that radiation may have triggered this deterioration, but it remains unclear whether this outcome would occur in other ME/CFS patients undergoing similar treatment.
This case highlights a potential and previously undocumented risk in ME/CFS populations: severe clinical deterioration associated with therapeutic radiation. For ME/CFS patients who require cancer treatment or other radiotherapy, this report suggests the need for careful risk assessment and informed consent discussions about potential exacerbation, as conventional radiation safety predictions may not apply to patients with possible underlying mitochondrial dysfunction.
This single case does not establish that proton beam therapy causes severe ME/CFS worsening in all or most ME/CFS patients; it does not confirm the proposed mechanisms (mitochondrial dysfunction, oxidative stress); and it does not provide guidance on safe radiation doses or treatment modifications for ME/CFS populations. The temporal association between radiotherapy completion and symptom escalation does not exclude other contributing factors.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Fischer, Christian, Seidlitz, Annekatrin, & Krause, Mechthild (2026). Significant aggravation of pre-existing myalgic encephalomyelitis/chronic fatigue syndrome following proton beam therapy for sphenoid wing meningioma: case report.. Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al]. https://doi.org/10.1007/s00066-026-02553-w
BibTeX
@article{mecfsatlas-fischer-2026-significant-aggravation,
author = {Fischer, Christian and Seidlitz, Annekatrin and Krause, Mechthild},
title = {Significant aggravation of pre-existing myalgic encephalomyelitis/chronic fatigue syndrome following proton beam therapy for sphenoid wing meningioma: case report.},
journal = {Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al]},
year = {2026},
doi = {10.1007/s00066-026-02553-w},
note = {PubMed: 42277311},
url = {https://www.mecfsatlas.com/evidence/fischer-2026-significant-aggravation},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-06-14. https://www.mecfsatlas.com/evidence/fischer-2026-significant-aggravation
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