MR Imaging of Lymphadenopathy in Rectal Cancer using the MR Agent Vasovist

Lymphadenopathy is a risk factor for local recurrence in rectal cancer. If one
can predict this risk factor preoperatively, together with other risk factors
for local recurrence, such as narrow circumferential resection margin, one is
able to develop tailored treatment for rectal cancer patiënt, preventing under-
as well as overtreatment. In this pilot study we would like to investigate
whether nodal status in rectal cancer can be predicted preoperatively using
Vasovist®-enhanced MRI.

Primary objective
• To validate the potential of Vasovist®-enhanced MRI for accurate prediction
of nodal status in patients with primary rectal cancer using histopathological
examination after surgery as the SOR.

Secondary objectives
• To compare the value of Vasovist®-enhanced MRI for prediction of nodal status
with unenhanced MRI
• To compare the total number of positive and negative lymph nodes in Vasovist®-
enhanced MRI with the total number of positive and negative lymph nodes in
unenhanced MR images
• To compare the potential of Vasovist®-enhanced MRI for detection of
extra-mesorectal lymph nodes with unenhanced MR imaging
• To assess image quality of Vasovist®-enhanced MRI in comparison to unenhanced
MRI
• To assess the confidence level of diagnosis of Vasovist®-enhanced MRI in
comparison to unenhanced MRI
• Safety of Vasovist® application (occurrence of adverse events)

Patients with primary rectal cancer will undergo MRI imaging of the pelvis
without contrast agent and after IV application of Vasovist®. The MR images
will be interpreted by experienced radiologists. Image findings of Vasovist®-
enhanced MRI (amongst others number of positive and negative lymph nodes, tumor
stage) will be compared with histopathology as the SOR and unenhanced MRI as
the comparator.

Patients will undergo MRI scan as a routine pretreatment investigation. In this
study, Vasovist® is administered during the MRI scan through intravenous
injection. Afterwards, postcontrast images will be made, therefore total scan
duration will be approximately 15 minutes longer. Furthermore, there is a small
risk of adverse events caused by the contrastagent.