MR-PET for staging and assessment of operability in ovarian cancer * a feasibility study

Very recently, the academic hospital Maastricht invested in an integrated
MR-PET system (Biograph mMR, Siemens Healthcare, Erlangen, Germany), ready to
use for routine clinical application. Applications of this system are numerous
and various types of cancer, including ovarian cancer, could benefit from the
possibilities. The whole-body MR-PET system integrates the strengths of MRI and
PET within a single examination. MRI provides anatomic detail in staging local
tumor extent due to its high soft tissue resolution and advanced functional
techniques such as DWI further enhance both local and distant lesion detection
and characterisation. PET imaging complements this structural and functional
information with molecular imaging technology useful in staging of adenopathy
and metastatic spread. These characteristics contribute to a wide spectrum of
possible clinical oncological applications, from primary tumor detection to
local and distant staging, selection of patients for neoadjuvant therapy and
assessment of response to chemotherapy and finally evaluation of recurrent
disease.

Primary Objective: To evaluate the diagnostic performance of MR-PET in
preoperative staging and evaluation of operability of women with advanced stage
epithelial ovarian cancer. Diagnostic accuracy in terms of sensitivity and
specificity of MR-PET will be compared to the current gold standard, CT
imaging. Histopathology in combination with intraoperative findings will be
used as the reference standard.

Prospective pilot study.

The MR-PET will be performed with the Biograph mMR system (Siemens Healthcare,
Erlangen, Germany). This system integrates a 3Tesla MRI and PET scan which
makes simultaneous acquisition of whole-body MRI and PET images possible. The
Biograph mMR holds the CE mark and was FDA approved in June 2011. The Biograph
mMR is intended to be used in the Academical hospital Maastricht for standard
patient care. The radiotracer that will be used is 18F-labeled
fluorodeoxyglucose (18F-FDG), according to standard PET-protocol.

The burden for patients exists of 1 MR-PET scan, total time: 60 minutes.
Radiation exposure is low and MR-PET is safe for patients with no
contra-indications to MRI. Patients with contra-indications will be excluded
for participation in this study.
Risks associated with undergoing MR-PET are claustrophobia and self-inflicted
injuries due to this claustrophobia, bleeding or burns in case of presence of
metal objects, tinnitus, dizziness and balance disorders.
The side effects of MRI contrast agent (Gadovist) are rare: nausea, vomiting,
urticaria, feeling of warmth, wheals (localized itchy oedema), dizziness,
cough, dyspnoea, severe anaphylactic reaction occur in less than 0,5% of cases.
Venipuncture/peripheral catheter insertion for administration of the PET tracer
and MRI contrast agent is rather safe and is part of routine patient care. The
occurrence of a local redness cannot be excluded.