Doris Leithner, Presenter: Nothing to Disclose

Pascal Andreas Thomas Baltzer MD, Abstract Co-Author: Nothing to Disclose

Heinrich Magometschnigg, Abstract Co-Author: Nothing to Disclose

Georg Johannes Wengert MD, Abstract Co-Author: Nothing to Disclose

Thomas Hans Helbich MD, Abstract Co-Author: Research Consultant, Siemens AG Research Consultant, Hologic, Inc Research Grant, Siemens AG

Katja Pinker-Domenig MD, Abstract Co-Author: Nothing to Disclose

Breast parenchymal enhancement (BPE) is considered to reflect tissue proliferative activity due to hormonal stimulation. It is regarded as a detrimental factor on diagnostic accuracy and, on the other hand, as a risk factor for breast cancer. Our purpose was to evaluate if breast parenchymal enhancement (BPE) with contrast-enhanced MRI of the breast at 3T correlates with quantitative maximum Standardized Up-take Values (SUVmax) in 18FDG breast PET-CT.

130 patients undergoing 18FDG PET-CT and 3T CE-MRI of the breast due to BIRADS 4 or 5imaging findings were included in this IRB approved prospective study. Examinations were scheduled no longer than 3 days apart. The MRI protocol included a contrast-enhanced 3D-T1-w sequence before and after application of a standard dose of 0.1 mmol/kg Gd-DOTA (Dotarem®). In all patients, a prone PET-CT dataset over the breasts was acquired allowing the same patient geometry as with MRI. Patients were injected with approximately 300 MBq 18FDG. Scanning was started 45 min after injection. CT data was used for attenuation correction. In all patients BPE and breast parenchyma SUVmax of the normal contralateral breast was recorded. BPE was qualitatively assessed by two independent readers and graded as none, mild, moderate and marked. Reader 1 re-assessed all cases. Appropriate statistical tests were used to assess correlation of BPE and SUVmax, inter- and intra-reader agreement.

There was no BPE in 58, mild in 54, moderate in 14 and marked in 4 patients. Due to the small number of marked BPE, moderate and marked BPE were considered together (n=28). SUVmax for patients with no BPE was 1.56 (SD 0.6), for mild BPE 1.9 (SD 0.6), for moderate/marked 2.3 (SD 0.6). SUVmax increased with BPE and there was a significant difference in SUVmax for patients with none and mild BPE (p=0.003) and none and moderate/marked BPE (p<0.01). There was no significant difference between mild and moderate/marked BPE (p=0.71). Inter-rater and intra-rater agreement for BPE was very good with a Kappa value of 0.862 and 0.805 respectively.

SUVmax of normal breast parenchyma is positively correlated with BPE in CE-MRI of the breast.

As higher SUVmax is expected in patients with moderate/marked BPE, a possible masking effect of lesions in such cases has to be considered.

Leithner, D, Baltzer, P, Magometschnigg, H, Wengert, G, Helbich, T, Pinker-Domenig, K, Is there a Correlation of Breast Parenchymal Enhancement in MRI and SUVmax in 18FDG Breast PET-CT?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13020503.html