GE Signa Pulse of MR - Spring 2012

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A 70-year-old patient diagnosed with
rectal cancer and liver metastases.
Initial staging was performed in
July 2011 including CT chest/
abdomen/pelvis exam and MR rectum
+ abdomen/pelvis exams. The first
course of chemotherapy targeted
the rectal and liver metastasis
adenocarcinoma and the patient
received follow up exams with CT
and MR in November 2011.

Initial CT staging showed multiple
metastases and cysts but also
hypodense undefined lesions in the
liver. A characterization MR exam was
performed in July 2011 in order to
clarify the status of the undefined
lesions. Target lesions were identified
on the initial CT exam in July 2011
(Figure 1). In November 2011, most
of the liver metastases decreased in
size (Figure 2), while hypodense lesions
appeared or increased on the CT exam
(Figure 3A). The MR exam demonstrated
a decrease in the size of the metastases
and the hypodense undefined lesions
found on the CT appeared to have a
rim enhancement on T1 weighted
images. Additionally, these lesions
increased in size and were suspicious
for metastasis (Figure 3B). A liver biopsy
concluded that these lesions were
mucinous metastases and confirmed
the split evolution of the rectal cancer.

The current guidelines used to assess
tumor response during treatment,
like RECIST, are based on anatomical
tumor size. When using specific drugs
for chemotherapy, only some groups
of cancer cells will respond while other
types of cells might continue to grow.
In this case, using only anatomical
guidelines may not be sufficient to
assess the response of the treatment
and other imaging modalities can
be used for the assessment.

Isabelle Boulay, MD, has spent over 14 years focusing on abdominal imaging in oncology, and reads/diagnoses everything from ultrasound, MR, and CT imaging. She completed her clinical fellowship at Hôpital Lariboisiere in the GI radiology department where thereafter she began her career sharing her time between the Institute Marie Curie in Paris and Saint-Joseph in the first three years. Since then, she has been working full time as part of the Paris Saint-Joseph group. The hospital group of Paris Saint-Joseph, administered by the Saint-Joseph Hospital Foundation, is a private nonprofit, participating with the national public hospital service.