18F-FDG PET/CT for early prediction of response to neoadjuvant chemotherapy in breast cancer.
OBJECTIVE
The aim of this study was to prospectively evaluate 18F-FDG PET/CT in predicting response to neoadjuvant chemotherapy in large primary breast cancer.


METHODS
Fifty consecutive patients underwent PET/CT at baseline and after the second cycle. Baseline MRI was performed to establish tumour size. All findings were confirmed by histopathological analysis. Changes in maximum standardized uptake value (SUV(max)) between baseline study and after two cycles of neoadjuvant chemotherapy (epirubicin + cyclophosphamide + taxanes) were compared using response evaluation criteria in solid tumours (RECIST) criteria and the Miller and Payne (M&P) scale.


RESULTS
The mean tumour size was 4.3 +/- 1.4 cm. Forty patients were considered responders and ten as non-responders. SUV(max) changes in patients with good prognosis (M&P grades 4-5) were higher than in patients with bad prognosis (M&P grades 1-3) (p = 0.025). SUV(max) changes between responders and non-responders following RECIST criteria were also statistically significant (p = 0.0028). A cut-off DeltaSUV value of 40% differentiates both groups, with a sensitivity of 77% and a specificity of 80%.


CONCLUSIONS
18F-FDG PET/CT can predict response to neoadjuvant chemotherapy at an early stage.
Duch
Joan
J
Nuclear Medicine Department, Hospital Clínic de Barcelona, Villarroel, 170, 08036, Barcelona, Spain. joanduch@gmail.com
Fuster
David
D
Muñoz
Montserrat
M
Fernández
Pedro Luís
PL
Paredes
Pilar
P
Fontanillas
Montserrat
M
Guzmán
Flavia
F
Rubí
Sebastià
S
Lomeña
Francisco Juan
FJ
Pons
Francesca
F