Evaluation of lymph node response with 3D-FSE CUBE imaging during chemoradiotherapy treatment of patients with head and neck squamous cell carcinoma.

Imaging studies in squamous cell carcinoma and accompanied lymph node
metastasis have so far focussed mainly on 2D-imaging techniques. E.g. a
disadvantage is the thickness of the slices in de CT imaging, using mostly 5 mm
slice thickness.[18] Therefore it is possible that measured sizes are an
approach of the true size, as lymph nodes commonly vary between 3 and 10 mm in
size.
3D imaging has certain advantages over 2D-imaging. When a scan is performed
with isotropic voxels, it is possible to reconstruct images in all desired
arbitrary planes.[23] Therefore the smallest and biggest axial diameter can be
measured adequately and the volume can be determined more accurately.

Most studies were small and show heterogeneous results. Most studies have used
CT. Although CT provides a good contrast between air, fat and bone, the
contrast between tumor and non-tumor is difficult to visualise. MRI imaging has
excellent soft tissue delineation and is therefore more suitable for tumor and
lymph node imaging. [20]

Current MRI with 3D-FSE CUBE sequence provides isotropic voxels. Slices in
3D-FSE CUBE are smaller in comparison with conventional 2D imaging. Partial
volume artefacts could be reduced.[24] In 3D-sequence the signal-to-noise-ratio
is better compared with 2D-imaging[25] and could provide better visualisation
of anatomical structures.[25, 26]
We expect that with this technique information about the location, size and
shape of the lymph nodes in head and neck can be generated with a relative
short imaging time.
With this technique we want to analyse the response of lymph nodes during
chemoradiotherapy, more particular to analyse whether volume decrease is
gradual over time.

Why is it important to assess the tumor and lymph node response during
treatment?
When volume change has been assessed, a biological model that predicts response
to treatment on the basis of early volume change can be realized. The best
time-point during chemoradiotherapy in which to evaluate the treatment effect
with imaging can be assessed.
This model allows for the possibility to predict response to therapy in an
early time frame in the future. When response to therapy can be evaluated,
treatment can be adjusted early in the course of treatment. Using this
biological model, further possibilities of the optimal time-frame to adapt the
dosage in adaptive radiotherapy can be explored.

To measure changes in lymph nodes on 3D CUBE imaging during (chemo)radiotherapy
of head and neck squamous cell carcinoma. By using serial imaging during
treatment with a relatively short scan time, we want to establish a biological
model of changes in lymph nodes during radiotherapy.

This study will be a single center diagnostic study. The duration of the study
will be 8 months, with an inclusion rate of 1 patient per 2 weeks.

Subjects in this study will not be at risk due to the MRI examination. The only
burden that they will have is that they undergo an additional 3D-CUBE MRI in
addition to the standard Baseline MRI, which takes a maximum additional
scanning time of approximately 6 minutes. In the 6 weeks of radiotherapy the
patient is asked to be scanned in the MRI scanner another three times at week
2, 4 and 6 weeks during radiotherapy treatment.