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Dedicated breast PET for detecting residual disease after neoadjuvant chemotherapy in operable breast cancer: A prospective cohort study

PURPOSEnDiagnostic methods to evaluate the response to neoadjuvant chemotherapy (NAC) for breast cancer have not been established. Dedicated breast PET (DbPET) is a high-resolution molecular breast imaging method, and we investigated the capability of DbPET to predict residual primary tumors after NAC compared with whole-body PET (WBPET).nnnMETHODSnForty-five patients (47 tumors) underwent WBPET and ring-type DbPET after NAC, and the tumors were completely resected between January 2016 and March 2017. The pathological response was classified as complete remission (ypT0), residual intraductal disease (ypTis), or residual invasive disease (ypTxa0≥xa01). Standardized uptake value (SUV) and tumor-to-normal tissue ratio (TNR) were assessed.nnnRESULTSnTwelve patients achieved ypT0 and five developed ypTis. DbPET detected all cases of ypTis, and WBPET detected only one case of ypTis. The sensitivity, specificity, and accuracy of WBPET for ypTis and/or ypTxa0≥xa01 were 54.3%, 83.3%, and 61.7%, respectively, and those of DbPET were 77.1%, 83.3%, and 78.7%, respectively. In the ypT0/ypTis/ypTxa0≥xa01 groups, the median WBPET-SUV, DbPET-SUV, and DbPET-TNR was 1.0/0.9/1.1, 1.7/1.8/2.2, and 1.0/1.6/1.7 (Pxa0=xa0.134, .077, and 0.008), respectively. Areas under the curves of WBPET-SUV, DbPET-SUV, and DbPET-TNR for predicting ypTis and/or ypTxa0≥xa01 were 0.610, 0.648, and 0.807, respectively.nnnCONCLUSIONSnDbPET was more accurate than WBPET in detecting residual primary tumors after NAC, particularly intraductal carcinoma. TNR was the better parameter for pathological evaluation compared with SUV.

Which type of breast cancers is undetectable on ring-type dedicated breast PET?

OBJECTIVESnTo assess the factors causing tumor undetectability on ring-type dedicated breast positron emission tomography (DbPET).nnnMETHODSnA total of 265 patients (288 tumors) underwent DbPET and contrast-enhanced magnetic resonance imaging (MRI) in a prone position. The distance between the shallowest part of the breast tumor and the front end of the pectoralis major muscle on MRI was considered as the tumor-to-chest wall distance.nnnRESULTSnTwenty-four tumors (8.3%) were not visualized via DbPET. The tumor-to-chest wall distance for undetectable tumors was shorter than that of the detectable tumors (23.0u202fmm vs 38.5u202fmm, Pu202f<u202f0.001). Multivariate analysis indicated that proximity to the chest wall and low-grade tumors were independent predicting factors for undetectable cancers. Among the 24 undetectable cancers, 15 tumors were proximal to the chest wall, suggesting that they were outside or at the edge of field of view (FOV), and 7 were low-grade tumors, suggesting insignificant 18F-fluorodeoxyglucose (FDG) uptake.nnnCONCLUSIONSnThe factors of undetectable breast cancers on DbPET are classified into two types; outside or at the edge of FOV and insignificant FDG uptake.

Pyopneumothorax during bevacizumab-containing chemotherapy in a patient with metastatic breast cancer

Pyopneumothorax is a rare but troubling complication of bevacizumab. We herein report a case of pyopneumothorax in a patient with metastatic breast cancer during bevacizumab treatment. A 60-year-old female who was diagnosed with metastatic breast cancer (ER+xa0, PgR+xa0, HER2-, Ki67 <14xa0%, metastasized to lung, pleural, brain, subcutaneous tissue, and bone) was started on bevacizumab plus paclitaxel chemotherapy. Although the disease was well-controlled, pyopneumothorax was noted after 3xa0months of treatment and the chemotherapy was therefore stopped immediately. The pyopneumothorax was so intractable that no conservative treatment could successfully manage it. The patient underwent a radical operation using the technique of latissimus dorsi muscle transfer. The operation improved her general condition and lead to hormonal therapy. Our case indicates the successful management of a severe side effect of bevacizumab for a breast cancer patient.