Early prediction of pathological complete response in luminal B type neoadjuvant chemotherapy-treated breast cancer patients: comparison between interim 18F-FDG PET/CT and MRI.
OBJECTIVE
The aim of this study is to justify the effectiveness of interim PET/computed tomography (CT) for predicting pathological complete response (pCR) in luminal B type breast cancer patients and to compare the diagnostic performance of interim PET/CT and MRI.


METHODS
Twenty-one patients with neoadjuvant chemotherapy (NAC)-treated luminal B type breast cancer were included. All patients underwent PET/CT and MRI at baseline and interim (mid-point). Breast surgery was performed after completion of NAC. Maximum standardized uptake values (SUV(max)) of breast malignant lesions in each PET/CT scan were acquired in each patient. The metabolic response was calculated as follows: ΔSUV (%) = (baseline SUV(max)-interim SUV(max))/baseline SUV(max) × 100 (%). In MRI, the relative size change was calculated as follows: Size change (%) = longest diameter interim MRI-longest diameter baseline MRI/longest diameter baseline MRI × 100 (%). pCR was concluded through the final pathologic specimen after breast surgery. The receiver-operating characteristic analysis was used as a statistical method.


RESULTS
Of 21 patients, seven achieved a pCR after surgery. In PET/CT, an optimal cut-off ΔSUV (%) of 69.0% was proposed with a sensitivity of 85.7% and a specificity of 100% (P < 0.0001). In MRI, an optimal cut-off size change (%) was 38.2% with a sensitivity of 64.3% and a specificity of 71.4% (P = 0.29). The area under the curve was 0.92 and 0.65, respectively. PET/CT presented better predictability of the pCR than MRI (P = 0.04).


CONCLUSIONS
In luminal B type NAC-treated breast cancer patients, it is possible to use PET/CT as an early surrogate marker for predicting pCR and it is significantly more predictable for pCR than MRI.
Department of Nuclear Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
Kisoo
K
Pahk
Sungeun
S
Kim
Jae Gol
JG
Choe
D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D064847:Multimodal Imaging; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019788:Fluorodeoxyglucose F18