Sung Hun Kim MD, Presenter: Nothing to Disclose

Ji-Hye Lee, Abstract Co-Author: Nothing to Disclose

Bong Joo Kang, Abstract Co-Author: Nothing to Disclose

Ie Ryung Yoo, Abstract Co-Author: Nothing to Disclose

To assess the diagnostic performance of MRI in evaluating response to neoadjuvant chemotherapy (NAC) in breast cancer patients especially in comparison to PET/CT.

Breast cancer patients who underwent NAC were included. Both MRI and PET/CT were performed before and 1~4 weeks after NAC.  Response to NAC was assessed by using response evaluation criteria in solid tumor (RECIST) 1.0 and PET response criteria in solid tumors (PERCIST) 1.0. Tumor volume on MRI and metabolic tumor volume on PET/CT were measured. Patients with complete or partial response on imaging studies were considered as responders, and stable or progressive disease as nonresponders. MRI and PET/CT findings were compared to post-operative histology.  The diagnostic accuracy of RECIST and PERCIST were compared and the diagnostic performance of MRI and PET/CT were compared by receiver operating characteristic (ROC) curve analysis.

Thirty three females  were included. Histology showed 17 responders and 16 nonresponders. MRI showed 20 responders, and agreed with histology in 24 of 33 cases (72.7%). PET/CT had 30 responders, and agreed with histology in 20 of 33 cases (60.6%). MRI had higher accuracy (72.7 vs. 60.6%). Between histologic responders and nonresponders, there were significant differences in reduction rate of RECIST as cut off value of 51.9% (50.5±25.3 vs. 23.1±17.9%) and tumor volume as cut off value of 69.3% (73.7±29.5 vs. 50.6±29.6), reduction rate of SUVmax as cut off value of 62.6% (71.6±17.5vs. 43.7±20.0%) and reduction rate of metabolic tumor volume (MTV) with SUV 2.0 as cut off value of 92.8% (96.4±4.1vs. 74.1±25.6%). On receiver operator curve analysis, areas under the ROC curves (Az values) were 0.807 for reduction rate of longest diameter, 0.827 for reduction rate of tumor volume, 0.864 for reduction rate of SUVmax  and 0.864 for reduction rate of metabolic tumor volume. 

PET/CT showed lower accuracy than MRI in evaluating response to NAC using the RECIST and PERCIST criteria, but reduction rate of metabolic tumor volume and SUVmax on PET/CT was comparable with that of tumor volume and longest diameter on MRI. Metabolic tumor volume could be helpful predictor of tumor response to NAC.

Reduction rate of metabolic tumor volume and SUVmax on PET/CT and tumor volume and longest diameter on MRI could be useful quantitative parameters to predict the tumor response to NAC.

Kim, S, Lee, J, Kang, B, Yoo, I, The Value of Pre- and Post-Neoadjuvant Chemotherapy MRI in Breast Cancer Comparison with F-18 FDG PET/CT Scans.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9006755.html