The role of mean diffusivity (MD) as a predictive index of the response to chemotherapy in locally advanced breast cancer: a preliminary study.
OBJECTIVE
To evaluate the role of mean diffusivity (MD) as a predictive index of the response to chemotherapy in locally advanced breast cancer.


METHODS
Twenty-one women referred to our institution with a diagnosis of locally advanced breast cancer underwent magnetic resonance imaging (MRI) studies at 1.5 T before beginning and after completing combined neoadjuvant chemotherapy. The examination protocol included an EPI sequence sensitised to diffusion (b-value 1,000 s/mm(2)) and three-dimensional (3D) coronal T1 sequences before and after intravenous contrast medium. Tumours were delineated by using dynamic MR acquisition before and after chemotherapy. The percentage of tumour volume reduction (PVR) and pre-(MD(pre)) and post-therapy (MD(post)) MD values were computed for each lesion.


RESULTS
PVR >or= 65% was observed in 17/21 patients (responders). MD(pre) of responders (0.99 +/- 0.27 10(-3) mm(2)/s) was significantly (p = 0.025) lower than MD(pre) of non-responders (1.46 +/- 0.33 10(-3) mm(2)/s). Moreover, in patients as a whole PVR significantly correlated (p = 0.01, r = -0.54) with MD(pre). MD(post) (1.26 +/- 0.39 10(-3) mm(2)/s) of responders was significantly(p = 0.024) higher than MD(pre) (0.99 +/- 0.27 mm(2) 10(-3) mm(2)/s), whereas non-responders MD(post) (1.00 +/- 0.14 10(-3) mm(2)/s)did not increase compared with MD(pre) (1.46 +/- 0.33 10(-3) mm(2)/s).


CONCLUSIONS
This preliminary study seems to indicate that low values of pre-chemotherapy MD may identify, before starting treatment, the patients with higher probability of response in terms of percentage of volume reduction of the lesion. MD may represent a complementary parameter useful to correctly select patients for neoadjuvant chemotherapy.
Iacconi
Chiara
C
Department of Radiology, Azienda Ospedaliero-Universitaria Pisana, Via Roma 67, 56100 Pisa, Italy. c.iacconi@med.unipi.it
Giannelli
Marco
M
Marini
Carolina
C
Cilotti
Anna
A
Moretti
Monica
M
Viacava
Paolo
P
Picano
Eugenia
E
Michelotti
Andrea
A
Caramella
Davide
D
D000368:Aged; D000465:Algorithms; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy*; D003520:Cyclophosphamide / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D015251:Epirubicin / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D015251:Epirubicin; D003520:Cyclophosphamide; D005472:Fluorouracil