Delayed Radiation Necrosis After Stereotactic Radiosurgery in a Patient Vaccinated for COVID-19

Overview

This case study presents a 66-year-old female who developed delayed radiation necrosis (RN) approximately 46 months after stereotactic radiosurgery (SRS) for brain metastases.

Background

Radiation necrosis is a complication of SRS for brain metastases, typically occurring within 6–24 months post-treatment. Late presentations of RN, occurring several years after SRS, are rare.

Data Highlights

No numerical data or trial data were provided in the source material.

Key Findings

• Delayed RN can occur several years after SRS.
• Imaging modalities, including amino acid PET, may not effectively differentiate RN from recurrent tumors.
• Histopathology remains the gold standard for diagnosing RN.

Clinical Implications

Clinicians should be aware of the potential for delayed RN in patients treated with SRS.

Conclusion

This case highlights the occurrence of delayed RN after SRS.

Related Resources & Content

1. Ramesh Rengan, MD, PhD, The ASCO Post, 2020 -- Expert Point of View
2. Immunotherapy, Radiosurgery Combination and Risk of Radiation Necrosis in Patients With Cancer Who Have Brain Metastases, The ASCO Post, 2025
3. In Era of Immunotherapy, Radiation Therapy May Become Essential Component of Systemic Treatments of Cancer, The ASCO Post, 2019
4. European Association for Neuro-oncology (EANO) Consensus Statement on Radiation Necrosis, Neuro-Oncology, 2026
5. Joint EANM/EANO/RANO/SNMMI practice guideline/procedure standard for PET imaging of brain metastases, European Journal of Nuclear Medicine and Molecular Imaging, 2024
6. Bone Marrow Transplantation — Acute Severe Interstitial Lung Disease Following BNT162b2 mRNA COVID-19 Vaccination in a Patient After HLA-Haploidentical Hematopoietic Stem Cell Transplant
7. European Association for Neuro-oncology (EANO) Consensus Statement on Radiation Necrosis | Neuro-Oncology | Oxford Academic
8. Joint EANM/EANO/RANO/SNMMI practice guideline/procedure standard for PET imaging of brain metastases: version 1.0 | European Journal of Nuclear Medicine and Molecular Imaging | Springer Nature Link
9. Resection of brain radionecrosis after stereotactic radiosurgery or radiotherapy: a meta-analysis - PMC
10. Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline - PMC
11. Radiation Brain Necrosis as a Late Complication of Stereotactic Radiotherapy for Recurrent Non-small Cell Lung Cancer with Brain Metastases in the Era of Long-term Survival: a Case Report
12. Frontiers | Late Radiation Necrosis Following Stereotactic Radiosurgery After COVID-19 Vaccination: A Case Report and Hypothesis of Immune-Mediated Inflammatory Activation
13. Radiomics-based Differentiation of Recurrent Brain Metastases from Treatment Effects: A Multi-Institutional Comparative Study with Advanced Imaging | Radiology: Imaging Cancer