Advanced magnetic resonance imaging techniques for assessing brain metastases response following stereotactic radiosurgery
Patel, Markand Mei, Nan Li, Xuanxuan Jen, Jian Ping Meade, Sara Benghiat, Helen Hartley, Andrew Wykes, Victoria Sanghera, Paul Sawlani, Vijay
Patel, Markand
Mei, Nan
Li, Xuanxuan
Jen, Jian Ping
Meade, Sara
Benghiat, Helen
Hartley, Andrew
Wykes, Victoria
Sanghera, Paul
Sawlani, Vijay
Abstract
Objective: Post-stereotactic radiosurgery (SRS) enlargement of brain metastases often creates diagnostic uncertainty that delays appropriate intervention. This study evaluates the combined role of delayed contrast-enhanced magnetic resonance imaging (MRI) (treatment response assessment maps, TRAM) and multiparametric MRI, including diffusion, perfusion, and spectroscopy in distinguishing tumour progression from radiation-induced changes.
Methods: A retrospective analysis was performed on 23 patients with 24 enlarging lesions following SRS. All patients underwent advanced MRI, including TRAM, dynamic susceptibility contrast perfusion (relative cerebral blood volume), and MR spectroscopy [MRS] (choline/creatine ratio). The diagnostic performance of each modality was assessed against radiological follow-up at 12 months.
Results: Of 22 evaluable lesions, 13 were classified as radiation-related changes and 9 as true progression. TRAM alone (clearance decrease >0%) demonstrated 100% sensitivity but only 38% specificity (accuracy 63%). Perfusion imaging (relative cerebral blood volume ≥2.0) achieved 77% accuracy, while MRS (choline/creatine ≥1.8) yielded 90% accuracy with 88% sensitivity and 92% specificity. Combining TRAM and MRS further improved performance. The best diagnostic accuracy (95%) was achieved through integrated neuroradiologist interpretation of all modalities, with 100% sensitivity and 92% specificity.
Conclusions: Advanced MRI incorporating TRAM, diffusion, perfusion, and spectroscopy improves diagnostic accuracy in post-SRS assessment of brain metastases. This multimodal approach enhances lesion characterization and supports timely treatment decisions, including reirradiation, surgery, or surveillance.
MIDER Authors
Date
2026-02-12
Type
Article
Subject
Radiosurgery, Magnetic resonance imaging, Radiation oncology, Brain neoplasms
Collections
Citation
Patel M, Mei N, Li X, Jen JP, Meade S, Benghiat H, Hartley A, Wykes V, Sanghera P, Sawlani V. Advanced Magnetic Resonance Imaging Techniques for Assessing Brain Metastases Response Following Stereotactic Radiosurgery. World Neurosurg. 2026 Apr;208:124866. doi: 10.1016/j.wneu.2026.124866. Epub 2026 Feb 12
Journal / Source Title
World Neurosurgery
DOI
10.1016/j.wneu.2026.124866
PMID
41690550
Publisher
Elsevier
Publisher’s URL
http://www.sciencedirect.com/science/journal/18788750