programma & abstracts - Nederlandse Vereniging voor Radiologie

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programma abstracts & abstracts
Figure 1: Whole brain CBF map.
Figure 2: Partial volume corrected gray matter CBF map.
Figure 3: Boxplot of gray matter CBF in SMC, MCI and AD.
UMC St Radboud
MR GESTUURDE PROSTAAT INTERVENTIES;
KLAAR VOOR DE PRAKTIJK?
J.J. Fütterer
Next to digital rectal examination and PSA level, biopsy of
the prostate is an essential procedure for determining optimal
treatment. Systematic TRUSBx is the gold standard, but
it fails to detect numerous tumors. This systematic approach
is characterized by low sensitivity (39–52%) and high specificity
(81–82%).
Using diagnostic MRimages during an MR-directed biopsy
procedure improves quality of the biopsy. In open MR scanners,
the prebiopsy MR images often must be registered to
the real-time biopsy images because open MR scanners do
not provide optimal tissue contrast; thus, the patient must
first be examined in a closed MR scanner and then biopsied
in an open scanner. The advantage of open MR over closed
MR is that the physician has easy patient access. Closed
MR scanners can be used for the prebiopsy scan as well as
for the biopsy procedure. Because operating room is limited
within the closed MR scanner, manipulators are used to perform
the biopsy. The MR detection rates after one negative
biopsy round using MR-guided biopsy ranges between 38%
and 55.5%.
The clinical value of MR-guided prostate biopsy lies in
the fact that a high percentage of prostate cancers can be
depicted using an targeted biopsy technique, eliminating
unnecessary systematic prostate biopsies for patients with
elevated PSA levels and repeated tumor-negative TRUSBx.
Extensive clinical studies are still essential to review the
value of MR-guided biopsy. One of the largest challenges
in taking biopsiesof the prostate is the correction for movements
of the prostate tissue during the biopsy procedure.
In conclusion the combination of a diagnostic MR examination
and MR-guided biopsy is a promising tool and may be
used in patients with previous negative TRUSBx.
MUMC
WAIT AND SEE IN RECTAL CANCER
PATIENTS: SELECTION BY IMAGING AND
OUTCOME
M. Maas, R.G.H. Beets-Tan
Locally advanced rectal cancer is treated with neoadjuvant
chemoradiation. In approximately 20% of the patients the
tumor and the involved lymph nodes disappear or become
sterilized due to this chemoradiation: a complete response.
With a combination of T2-weighted MRI, diffusion-weighted
MRI, gadofosveset-enhanced MRI and endoscopy these
patients can be selected for a ‘wait-and-see policy’, in which
surgery is omitted and patients undergo intensive follow-up.
Maastricht University Medical Centre is the only Dutch
centre that currently performs a study to evaluate this waitand-see
policy with MRI-based selection and follow-up. The
preliminary results are very encouraging and for the future
we expect to be able to offer this wait-and-see policy safely
to complete responders after neoadjuvant chemoradiation.
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