Dynamic contrast enhanced-MRI for the detection of pathological complete response to neoadjuvant chemotherapy for locally advanced rectal cancer

Abstract

Dynamic contrast enhanced (DCE) MRI provides perfusion characteristics of tumours. These objective quantitative measures may be more helpful than subjective imaging alone Some parameters differed markedly between completely responding and incompletely responding rectal cancers. Thus DCE-MRI can potentially offer treatment-altering imaging biomarkers.

Standardized Index of Shape (SIS): a quantitative DCE-MRI parameter to discriminate responders by non-responders after neoadjuvant therapy in LARC

“…Kim et al [31] showed that the K trans parameter (contrast agent transfer constant between plasma space to extracellular extravascular space) had a large decrease in the mean value after CRT and this was associated with a good therapeutic response to CRT for LARC. However, being influenced by many factors, many different models are still present in the literature and their high output variability reflects a poor clinical reliability [8,16,18,32]. Results of quantitative analysis to assess therapy response on 3T MR scanners are more promising, as was reported in the studies of Intven et al [33] and Lim et al [34].…”

“…Residual tumour within the fibrotic areas is frequently represented by small tumour nests, beyond the depiction level of morphological MRI [21]. According to T stage after CRT, Chen et al [8] reported an overstaging of 38 % and an accuracy of 52 %. With regard to qualitative DCE-MRI, the main drawback remains ROI positioning, which makes the evaluation operator dependent [7].…”

“…Studies are therefore focusing on the potential added benefit of functional and/or quantitative methods of MR image evaluation. Dynamic contrast-enhanced MRI (DCE-MRI) has proven useful in detecting residual tumour after CRT [5][6][7][8][9]: leaky capillaries associated with tumour neovascularization determine a rapid gadolinium uptake and an early wash-out, which correlate with the vascular endothelial growth factor (VEGF) expression and micro vessel density (MVD) [10][11][12]. DCE-MRI evaluation can be assessed through time intensity curve (TIC) analysis performed using three different approaches: qualitative DCE-MRI, quantitative DCE-MRI and semiquantitative DCE-MRI based on pattern analysis.…”

MRI in local staging of rectal cancer: an update

“…Kremser et al (66) applied dynamic T1 mapping as a predictor of post-chemoradiotherapy outcome. Gollub et al (67) showed that dynamic contrast-enhanced MRI is reliable in predicting pathological complete response after chemotherapy; the authors suggested that this could help identify patients with favorable risk in whom a more conservative approach could be preferred to radical resection. However, the benefit of using intravenous gadolinium in the staging of rectal cancer is still debated, and gadolinium use is not recommended by some groups (20,21).…”

Bedeutung der Schnittbildverfahren für das Staging des Rektumkarzinoms

“…Prinzipiell eignen sich für die Responsebeurteilung MRT, CT-Perfusion und PET/CT. Aufgrund der fehlenden Strahlenexposition, der hohen Weichteilauflösung und der Integration von Morphologie und Funktion scheint insbesondere die MRT für die frühe Response-Prädiktion exzellente Voraussetzungen zu besitzen, was sich nicht zuletzt in der aktuellen Literatur zu diesem Thema widerspiegelt [1,5,6,7,17]. Unklar bleibt einerseits welche Parameterkombinationen für eine frühe Response-Beurteilung erforderlich sind und andererseits zu welchen Zeitpunkten nach Therapieeinleitung idealerweise eine Bildgebung stattfinden sollte.…”