Data sources and search strategy
We performed a primary literature search on MEDLINE for DCE-MRI,
Ve and variations thereof with the following search string:
((((((Dynamic contrast-enhanced MRI[Title]) OR DCE-MRI[Title]) OR Dynamic contrast-enhanced magnetic resonance imaging[Title]) OR Dynamic contrast enhanced MRI[Title]) OR DCE MRI[Title]) OR DCE[Title]) AND ("Ve"[Title/Abstract] OR "V(e)"[Title/Abstract]).
Based upon our inclusion/exclusion criteria 27 out of 314 articles were eligible,
totalling 1128 patients with a variety of primary tumours.
Selection criteria
Results were limited to human studies in English.
Studies were included if they measured and reported Ve either pre or pre and post intervention (either chemotherapy or radiotherapy) with prognosis or survival as an endpoint.
Studies were also excluded if their primary aim was to differentiate tumour subtypes or stage based upon DCE-MRI parameters.
PRISMA guidelines for transparent reporting of systematic reviews were followed.
Data extraction
Data extracted from the full text articles included the type of cancer studied,
sample size,
follow up time,
primary outcome measure,
timing of scans,
DCE parameters measured,
the nature of the semiquantitative/quantitative analysis and a summary of findings.
Findings
Studies were heterogeneous with differences in primary tumours,
image acquisition parameters,
coregistration methods,
pharmacokinetic models used to derive the quantitative parameters,
AIF methods,
ROI acquisition and therapy delivered (chemotherapy vs.
radiotherapy).
Five papers showed a significant negative correlation between Ve and tumour response/patient survival ([4],
[5],
[6],
[7],
[8]) whereas four papers showed a significant positive correlation ([9],
[10],
[11],
[12]).
16 studies did not demonstrate a statistically significanct difference between patients with differing response to therapy.
One paper analysed change in Ve only [13] and found a significant association with survival whereas three found significance in Ve histogram data [5],
[14],
[15].