Probabilistic independent component analysis of dynamic susceptibility contrast perfusion MRI in metastatic brain tumors

Ararat Chakhoyan,Jason Chen,Nader Pouratian,Tania B Kaprealian,Jingwen Yao,Catalina Raymond,Benjamin M Ellingson,Jodi Goldman

doi:10.1186/s40644-019-0201-0

Ararat Chakhoyan, Jason Chen + Show 6 more

Open Access

https://doi.org/10.1186/s40644-019-0201-0

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Abstract

PurposeTo identify clinically relevant magnetic resonance imaging (MRI) features of different types of metastatic brain lesions, including standard anatomical, diffusion weighted imaging (DWI) and dynamic susceptibility contrast (DSC) perfusion MRI.MethodsMRI imaging was retrospectively assessed on one hundred and fourteen (N = 114) brain metastases including breast (n = 27), non-small cell lung cancer (NSCLC, n = 43) and ‘other’ primary tumors (n = 44). Based on 114 patient’s MRI scans, a total of 346 individual contrast enhancing tumors were manually segmented. In addition to tumor volume, apparent diffusion coefficients (ADC) and relative cerebral blood volume (rCBV) measurements, an independent component analysis (ICA) was performed with raw DSC data in order to assess arterio-venous components and the volume of overlap (AVOL) relative to tumor volume, as well as time to peak (TTP) of T2* signal from each component.ResultsResults suggests non-breast or non-NSCLC (‘other’) tumors had higher volume compare to breast and NSCLC patients (p = 0.0056 and p = 0.0003, respectively). No differences in median ADC or rCBV were observed across tumor types; however, breast and NSCLC tumors had a significantly higher “arterial” proportion of the tumor volume as indicated by ICA (p = 0.0062 and p = 0.0018, respectively), while a higher “venous” proportion were prominent in breast tumors compared with NSCLC (p = 0.0027) and ‘other’ lesions (p = 0.0011). The AVOL component was positively related to rCBV in all groups, but no correlation was found for arterial and venous components with respect to rCBV values. Median time to peak of arterial and venous components were 8.4 s and 12.6 s, respectively (p < 0.0001). No difference was found in arterial or venous TTP across groups.ConclusionsAdvanced ICA-derived component analysis demonstrates perfusion differences between metastatic brain tumor types that were not observable with classical ADC and rCBV measurements. These results highlight the complex relationship between brain tumor vasculature characteristics and the site of primary tumor diagnosis.

Highlights

Brain metastases are the most common type of intracranial neoplasm [1, 2]
If a metabolically active region was detected within the brain, it was assumed to be due to the primary tumor type, and a subsequent high-resolution brain magnetic resonance imaging (MRI) was performed
No significant difference in median Contrast-enhancing tumors (CET) apparent diffusion coefficients (ADC) or median CET relative cerebral blood volume (rCBV) was observed between groups (Fig. 3b and C, respectively)

Summary

Introduction

The majority of brain metastases originate from primary cancers in the lung (40– 50%), breast (15–25%) or melanoma (5–20%) [3, 4]. Recent studies speculate that tumor can grow at a clinically detectable stage with vessel co-option [6], a non-angiogenic mechanism [7]. Such processes have been reported in non-small cell lung tumors (NSCLC) [8] and melanoma [9]. Evidence suggests significant differences in vascular density between breast and melanoma brain metastases that may be influenced by genetic factors, including the expression of CD105, a transforming growth factor (TGF)-beta receptor endoglin [12]

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