PRIMARY OBJECTIVE:~I. To estimate the negative predictive value (NPV) of neoadjuvant interim (ni)FDG-PET/CT for pathologic complete response (pCR), using delta maximum standardized uptake value corrected for lean body mass day 15 (deltaSULmaxD15), completed through central review, of the primary breast cancer at a threshold of 40%, in patients treated with neoadjuvant HER2-directed therapy.~SECONDARY OBJECTIVES:~I. To estimate the sensitivity, specificity, and positive predictive value (PPV) of niFDG-PET/CT for pCR, using deltaSULmaxD15 of the primary breast cancer at a threshold of 40%, in patients treated with neoadjuvant HER2-directed therapy.~II. To evaluate the performance of niFDG-PET/CT, using deltaSULmaxD15 of the primary breast cancer at a threshold of 40%, as a predictor of 3-year event-free survival (EFS) from time of study registration.~EXPLORATORY OBJECTIVES:~I. To estimate the NPV of niFDG-PET/CT for pCR, using deltaSULmaxD15 of the primary breast cancer at a grid of alternative thresholds ranging from 30% to 60%, in patients treated with neoadjuvant HER2-directed therapy.~II. To compare deltaSULmaxD15 using automated image analysis of FDG-PET/CT by AutoPERCIST (trademark) to standard PET analysis software.~OUTLINE:~Patients receive FDG intravenously (IV), undergo PET/CT, receive standard of care chemotherapy, and undergo standard of care surgery on study.
This phase II trial tests how well an imaging procedure called fludeoxyglucose F-18 (FDG) positron emission tomography/computed tomography (PET/CT) works in predicting response to standard of care chemotherapy prior to surgery in patients with HER2-positive stage IIa-IIIc breast cancer. FDG is a radioactive tracer that is given in a vein before PET/CT imaging and helps to identify areas of active cancer. PET and CT are imaging techniques that make detailed, computerized pictures of areas inside the body. The use of FDG-PET/CT may help doctors better decide if a patient needs more or less treatment before surgery in order to get the best response. This study evaluates whether FDG-PET/CT is useful in predicting a patient's response to standard of care chemotherapy.