Sonja Kinner MD, Presenter: Nothing to Disclose

Johannes Grueneisen, Abstract Co-Author: Nothing to Disclose

Oliver Hoffmann, Abstract Co-Author: Nothing to Disclose

Ann-Kathrin Bittner, Abstract Co-Author: Nothing to Disclose

James Nagarajah, Abstract Co-Author: Nothing to Disclose

Thorsten D. Poeppel, Abstract Co-Author: Nothing to Disclose

Agnes Bankfalvi, Abstract Co-Author: Nothing to Disclose

Kai Nassenstein, Abstract Co-Author: Nothing to Disclose

To assess if simultaneous 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) magnetic resonance mammography (MRM; PET/MRM) performed before and after neoadjuvant chemotherapy (NAC) can discriminate between responders and non-responders and predict response to therapy in patients with invasive breast cancer compared to PET and MRM alone.

15 Patients with initial diagnosis of invasive breast cancer underwent simultaneous PET/MR mammography (Biograph mMR, Siemens, Erlangen, Germany) before and under NAC. Two readers evaluated in consensus i) MR mammography concerning size difference, ii) PET concerning changes of standard uptake value and iii) simultaneous PET/ MRM concerning both features to determine response. Image ratings were correlated with histopathology (complete response: CR; non-complete response: non-CR) and regression score after Sinn (0: no effect; 4: no residual tumor detectable) after breast conserving surgery or mastectomy.

Overall, MR mammography alone diagnosed CR in 8 patients and non-CR in 7 patients while PET alone diagnosed CR in 9 patients and non-CR in 6 patients. With PET/MRM readers were able to diagnose CR in 8 patients and non-CR in 7 patients. One patient with no definable tracer uptake on PET (rated as CR) showed a residual contrast enhancing lesion on MRM (non-CR) and was diagnosed correctly as non-CR on PET/MR with a Sinn score of 2 on histopathological examination. On the other hand, in another patient with a reduction of SUV (PET: non-CR but responder) and no change in size (MRM: non-CR, non-responder) histopathology showed partial reaction with a Sinn score of 2. PET/MRM correctly diagnosed this patient as non-CR, responder.

In this preliminary study we could show that simultaneous PET/MR mammography in breast cancer patients under NAC is feasible. Both imaging modalities complement one another and can help to distinguish responders from non-responders as well as predict complete response or non-CR.

The combination of PET and MRM helps to discriminate responder and non-responder as well as those with CR and non-CR. PET/ MRM can therefore be a valuable diagnostic tool for breast cancer patients undergoing NAC.

Kinner, S, Grueneisen, J, Hoffmann, O, Bittner, A, Nagarajah, J, Poeppel, T, Bankfalvi, A, Nassenstein, K, Value of Simultaneous PET MR Mammography in Patients with Breast Cancer Undergoing Neoadjuvant Chemotherapy – Preliminary Results.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011130.html