Detection of recurrent head and neck squamous cell carcinomas with DW-MRI after (chemo)radiation

Post-radiation changes make diagnosis of recurrent or persistent head and neck
squamous cell carcinomas (HNSCC) after (chemo)radiation challenging. Imaging
modalities such as CT and conventional MRI often have difficulties
discriminating between post-radiation changes and tumour recurrence. Metabolic
imaging such as FDG-PET has additional value, but limitations due to low
spatial resolution and false-positive results caused by inflammatory disease
remain. Recent studies have shown that diffusion weighted MRI (DW-MRI) could be
an imaging modality with promising capacity in differentiating between
recurrence and post-radiation changes. Increased differentiation might lead to
a reduction of futile biopsies with need of an endoscopy under general
anaesthesia. Moreover, DW-MRI might allow early diagnosis of recurrence.

To study the diagnostic capacity of DW-MRI for detecting recurrence in patients
with suspicion of recurrent or persistent HNSCC after initial (chemo)radiation.
This study aims to enhance early, low cost detection of recurrence and avoid
futile biopsies with need for general anaesthesia.

A prospectively designed diagnostic study to evaluate the diagnostic capacities
of DW-MRI in patients with suspicion of recurrent or persistent HNSCC. All
consecutive patients suspected of recurrent or persistent HNSCC in the UMC
Utrecht will receive a DW-MRI added to the regular imaging. If either the
regular imaging or the DW-MRI is suggestive for recurrence, biopsy will follow
for histological confirmation. If the regular imaging and DW-MRI are both
negative, patients remain in expectative follow up as in the regular protocol.
Reference standard is presence or absence of a histological proven recurrence
within 6 months after the suspicion.

Apart from regular imaging modality (CT, MRI or FDG-PET scan) patients will
undergo DW-MRI. No relevant risks associated with MRI for patients without
contra-indication and a normal renal function have been reported. The DW-MRI
will be scheduled so that the patient can combine a visit to the hospital for
clinical and study purposes.
Only in patients who have negative regular imaging and positive DW-MRI , the
diagnostic protocol will differ from the regular protocol. They will undergo
endoscopy with taking of a biopsy as they normally would not. These patients
might benefit if conventional imaging is false-negative and DW-MRI is
true-positive (since studies on DW-MRI reported higher sensitivity and
specificity than conventional imaging). However, the DW-MRI might also be
false-postive. In that case, the patient undergoes unnecessary endoscopy with
taking of a biopsy with risks such as infection, bleeding and the risk of
general anaesthesia. However, these are very rare complications.