Dedicated Breast PET/MRI in Evaluation of Extent of Disease in Women With Newly Diagnosed Breast Cancer

Blinded breast imaging readers were provided at random a reading list of anonymized studies of breast PET/MRIs and MRI alone from the study cohort and asked to assess lesions suspicious for malignancy. Specificity of all lesions on PET-MRI compared to MRI alone is assessed by the percentage of true negatives out of all benign/non-malignant lesions.

Blinded radiologists evaluated a list of anonymized studies of breast MRI alone and after washout period the same MRI with ovelayed PET from a hybrid PETMRI study cohort and asked to assess lesions suspicious for malignancy in addition to known index tumor. Measures of diagnostic accuracy( sensitivity, specificity, PPV and NPV) for any and all additional lesions exclusive of the known index tumor detected by readers were calculated for MRI alone and for PET/MRI. Due to washout period readers assessed the imaging of hybrid PET/MRI in complement, as such readers may assess previously questioned MRI findings as benign in the absence of FDG uptake. Sensitivity is the % of true positive & specificity is the % of true negative. PPV is the probability that if imaging was assessed as suspicious on biopsy was malignant. NPV is the % likelihood that if imaging was assessed as negative there was no additional malignancy on surgical excision.

PET imaging was assessed for signal-to-noise ratio of maximum standardized uptake value (SUVmax) over the breast background SUVmean. This is compiled below for each administered dose of FDG. Each subject received one FDG and one gadolinium dose IV injection.

Blinded breast imaging readers were provided at random a reading list of anonymized studies of breast PET/MRIs and MRI alone from the study cohort and asked to assess nodal disease as a whole (present/absent). Sensitivity, specificity, PPV (positive predictive value), and NPV (negative predictive value) of nodal metastasis (presence or absence) of hybrid breast FDG PET/MRI vs breast MRI alone were compared. Due to washout period readers assessed the imaging of hybrid PET/MRI in complement, as such readers may assess previously questioned MRI findings as benign in the absence of FDG uptake.

Subjects will be asked to fill out a questionnaire at the conclusion of their breast PET/MRI exam assessing on a scale of 1 - 5 how important it was for them to save time to do the PET/MRI simultaneously knowing that they may have a negative PET/MRI for extent of disease (no additional sites of disease aside from index cancer), how valuable it is for them to potentially avoid unnecessary biopsies if the study hypothesis is correct, and how important it is to them to decrease delay to surgery.