Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Mar;31(2):297-305.
doi: 10.1111/jon.12823. Epub 2020 Dec 22.

MRI Detection of Changes in Tissue Sodium Concentration in Brain Metastases after Stereotactic Radiosurgery: A Feasibility Study

Sherif A Mohamed  1 , Anne Adlung  2 , Arne M Ruder  3 , Michaela A U Hoesl  2 , Lothar Schad  2 , Christoph Groden  1 , Frank A Giordano  4 , Eva Neumaier-Probst  1
Affiliations

MRI Detection of Changes in Tissue Sodium Concentration in Brain Metastases after Stereotactic Radiosurgery: A Feasibility Study

Sherif A Mohamed et al. J Neuroimaging. 2021 Mar.

Abstract

Background and purpose: To date, treatment response to stereotactic radiosurgery (SRS) in brain metastases (BM) can only be determined by MRI evaluation of contrast-enhancing lesions in a long-time follow-up. Sodium MRI has been a subject of immense interest in imaging research as the measure of tissue sodium concentration (TSC) can give valuable quantitative information on cell viability. We aimed to analyze the longitudinal changes of TSC in BM measured with 23 Na MRI before and after SRS for assessment of early local tumor effects.

Methods: Seven patients with a total of 12 previously untreated BM underwent SRS with 22 Gy. In addition to a standard MRI protocol including dynamic susceptibility-weighted contrast-enhanced perfusion, a 23 Na MRI was performed at three time points: (I) 2 days before, (II) 5 days, and (III) 40 days after SRS. Nine BMs were evaluated. The absolute TSC in the BM, the respective peritumoral edemas, and the normal-appearing corresponding contralateral brain area were assessed and the relative TSC were correlated to the changes in BM longest axial diameters.

Results: TSC was elevated in nine BM at baseline before SRS with a mean of 73.4 ± 12.3 mM. A further increase in TSC was observed 5 days after SRS in all the nine BM with a mean of 86.9 ± 13 mM. Eight of nine BM showed a mean 60.6 ± 13.3% decrease in the longest axial diameter 40 days after SRS; at this time point, the TSC also had decreased to a mean 65.1 ± 7.9 mM. In contrast, one of the nine BM had a 13.4% increase in the largest axial diameter at time point III. The TSC of this BM showed a further TSC increase of 80.1 mM 40 days after SRS.

Conclusion: Changes in TSC using 23 Na MRI shows the possible capability to detect radiobiological changes in BM after SRS.

Keywords: 23Na-MRI; Brain metastases; stereotactic radiotherapy; tissue sodium concentration.

PubMed Disclaimer

References

    1. Chen Z, Zu J, Li L, et al. Assessment of stereotactic radiosurgery treatment response for brain metastases using MRI based diffusion index. Eur J Radiol Open 2017;4:84-8.
    1. Goethe EA, Rao G, Harvey A, et al. Temporal change in tumor volume following stereotactic radiosurgery to a single brain metastasis. World Neurosurg 2020;136:e328-33.
    1. Jakubovic R, Sahgal A, Ruschin M, et al. Non tumor perfusion changes following stereotactic radiosurgery to brain metastases. Technol Cancer Res Treat 2015;14:497-503.
    1. Trifiletti DM, Lee CC, Kano H, et al. stereotactic radiosurgery for brainstem metastases: an international cooperative study to define response and toxicity. Int J Radiat Oncol Biol Phys 2016;96:280-8.
    1. Da Silva AN, Nagayama K, Schlesinger D, et al. Early brain tumor metastasis reduction following Gamma Knife surgery. J Neurosurg 2009;110:547-52.

Publication types

LinkOut - more resources