In British Journal of Radiology Rutger Stijns and colleagues, theme tumors of the digestive tract, showed that using MRI with endorectal filling did not lead to an improved rectal cancer staging and that it has the potential to influence the distance to a key anatomical landmark.ABSTRACT
To assess the influence of endorectal filling (EF) on rectal cancer staging.
47 patients who underwent a staging MRI of rectal cancer in the period from 2011 to 2014 were included. The MRI protocol included T2 weighted fast spin echo sequences without and with EF at 3 T (EF-MRI). Images were scored by two readers for T-stage, distance of the lower pole of the tumour to the anorectal junction, distance to the mesorectal fascia (MRF), and number of (suspicious) lymph nodes. Agreement in T-staging was calculated using the Cohen's κ value. Comparison of continuous variables was performed using Wilcoxon matched pairs signed-rank test.
The interobserver agreement for T-staging with and without EF-MRI showed a poor agreement between both readers (weighted κ = 0.156, weighted κ = 0.037, respectively). Tumours tended to be overstaged more prominently with EF-MRI. The accuracy of predicting the pathological T-stage slightly improved from 55% with EF to 64% without EF for Reader 1 and from 59 to 68% for Reader 2, respectively. The distance of the tumour to the anorectal junction increased from 33.9 to 49.3 mm (p < 0.001) after EF for Reader 2. EF-MRI did not significantly influence the number of (suspicious) lymph nodes and distance to the mesorectal fascia.
EF-MRI did not lead to an improved tumour staging and it has the potential to influence the distance to a key anatomical landmark. EF-MRI is therefore not recommended in primary staging rectal cancer. Advances in knowledge: EF-MRI may not be used as an additional tool to stage rectal cancer patients, as it does not seem to facilitate in locoregionally staging the disease.
The influence of endorectal filling on rectal cancer staging with MRI.
Stijns RC, Scheenen TW, de Wilt JH, Fütterer JJ, Beets-Tan RG.