Abnormal vascularization of soft-tissue sarcomas on conventional MRI: Diagnostic and prognostic values.
European Journal of Radiology, Aug 2019
Ledoux P, Kind M, Le Loarer F, Stoeckle E, Italiano A, Tirode F, Buy X, Crombé A.
To assess the prevalence of abnormal vessels inside and surrounding soft-tissue sarcomas (STS) on conventional MRIs so as to evaluate their correlations with particular histotypes, histological grades, and prognosis.
This single-center retrospective study included 157 adult patients (median age: 61) with histologically-proven non-metastatic STS. All had pre-treatment conventional contrast-enhanced MRI. Two radiologists reported: presence of abnormal flow-voids, number and distribution (peri-tumoral and/or intra-tumoral), percentage of tumor circumference it covered, maximal diameter. The radiological findings were correlated with histopathology. Associations were evaluated with Chi-2 or t-tests. Survival analysis (for metastasis-free survival (MFS) and overall survival (OS)) included log-rank tests and multivariate Cox-model.
Twenty-nine of 157 (18.5%) STS showed abnormal flow-voids that were peri-tumoral (9/157, 5.7%), intra-tumoral (5/157, 3.2%) or both intra- and peri-tumoral (15/157, 9.6%). Ten STS had more than 5 flow-voids, all being grade II-III, namely: 4 undifferentiated sarcomas, 2 solitary fibrous tumors, 1 alveolar soft-part sarcoma (ASPS), 2 leiomyosarcomas and 1 pleomorphic liposarcoma. The distribution of flow-voids was associated with survivals in the univariate analysis: patients with abnormal peritumoral flow-voids (APTFV) showed poorer OS and MFS (p = 0.039 and 0.014, respectively). These associations did not remain significant in multivariate analysis. Radio-pathological correlations revealed large tortuous tumoral neo-vessels with intra-vascular thrombi of tumor cells in ASPS and in one case of undifferentiated sarcoma displaying enrichment in genes involved in neo-angiogenesis at transcriptional level.
APTFV on conventional MRIs may be associated with a higher risk of metastatic relapse and poorer OS in STS patients.