Pilot study: the use of PET-MRI in work-up of breast cancer patients.

Neoadjuvant chemotherapy (NAC) is one of the standard therapies for locally
advanced breast cancer. Several randomized controlled trials have shown that
NAC is as effective as adjuvant chemotherapy and that patients subjected to NAC
are more likely to undergo breast-conserving surgery, without compromising
oncologic outcomes. Moreover, the use of NAC permits the in-vivo monitoring of
the tumor response and identification of patients in which further treatment
may be necessary.
Clinically, it has been established that only complete pathological remission
after NAC has adequate clinically relevant prognostic power. The challenge for
imaging will be to identify non-responding patients much earlier during
treatment and to characterize the nature of this resistance. There is ample
evidence to suggest that MRI (DWI, DCE) and PET (18F-FDG) predict pathological
response NAC. However, current results of either technique when performed in
isolation are far from perfect.
There is a clinical need to understand whether and how information from these
techniques might improve overall prediction, and to investigate the mechanisms
of resistance. This requires image guided biopsies of PET and MRI signals
obtained in a comprehensive manner to allow for a thorough analysis of signal
heterogeneity. PET-MRI is the only hybrid technique for such research. For PET,
our initial focus will be put on 18F-FDG, but other tracers that assist in
phenotyping the disease (FES, FDHT, 89Zr-trastuzumab) are also available, to be
implemented beyond technical feasibility phases.

The primary objective of this study is to evaluate the ability of PET-MRI (
PET, DWI and DCE-MRI) to detect and locally stage breast cancer in patients.

Feasibility pilot study:
All these patients will routinely (as standard of care) undergo a PET- CT
after the diagnosis of breast cancer and a MRI of the breast. Instead of the
routine MRI a combined PET-MRI will be made within 90 minutes after the
PET-CT.
The extra burden is the prolonged scantime in prone position during the PET-MRI
compared to the breast MRI of 10-20minutes.
There is no additional exposure to radiation and the patients only need a
single dose of FDG for both PET-CT and PET-MRI.

All participating patients will receive routine follow-up imaging of the NAC
according to normal standards in the VU University Medical Center (breast MRI
before, sometimes after 3 cycles of NAC and pre-surgery ). The extra burden is
the prolonged scantime in prone position during the PET-MRI compared to the
breast MRI.
There is no additional exposure to radiation and the patients only need a
single dose of FDG for both PET-CT and PET-MRI.