Dynamic susceptibility contrast MRI may contribute in prediction of stereotactic radiosurgery outcome in brain metastases

Abstract

Background Following stereotactic radiosurgery (SRS), predicting treatment response is not possible at an early stage using structural imaging alone. Hence, the current study aims at investigating whether dynamic susceptibility contrast (DSC)-MRI estimated prior to SRS can provide predictive biomarkers in response to SRS treatment and characterize vascular characteristics of pseudo-progression. Methods In this retrospective study, perfusion weighted DSC-MRI image data acquired with a temporal resolution of 1.45 seconds were collected from 41 patients suffering from brain metastases. Outcome was defined based on lesion volume changes in time (determined on structural images) or death. Motion correction and manual lesion delineation was performed prior to semi-automated, voxel-wise perfusion analysis. Statistical testing was performed using linear regression and a significance threshold at p = 0.05 Age, sex, primary cancers (pulmonary cancer and melanoma), lesion volume and dichotomized survival time were added as covariates in the linear regression models (ANOVA). Results Relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) was found to be significantly lower prior to SRS treatment in patients with increasing lesion volume or early death post SRS (p ≤ 0.01). Conclusion Unfavorable treatment outcome may be linked to low perfusion prior to SRS. Pseudo-progression may be preceded by a transient rCBF increase post SRS. However, results should be verified in different or larger patient material.

Radiological Biomarkers for Brain Metastases Prognosis: Quantitative Magnetic Resonance Imaging (MRI) Modalities As Non-invasive Biomarkers for the Effect of Radiotherapy

“…Similar results were reported by Kuo et al They found that increased relative CBV can differentiate between tumor recurrence and post-radiation changes in patients with brain metastases [45]. Of interest, Starck et al found that pre-radiotherapy relative CBV and CBV are significantly decreased in patients with brain metastases who had true progression or early death after radiotherapy [46].…”

“…Similar results were reported by Kuo et al They found that increased relative CBV can differentiate between tumor recurrence and post-radiation changes in patients with brain metastases [ 45 ]. Of interest, Starck et al found that pre-radiotherapy relative CBV and CBV are significantly decreased in patients with brain metastases who had true progression or early death after radiotherapy [ 46 ]. Using DCE and DSC, Morabito et al found that there is a significant correlation between diagnosing recurrent brain metastases with Ktrans (98% of sensibility and 97% of specificity) and with rCBV (88% of sensitivity and 75% of specificity) [ 47 ].…”