This study investigated the relationship between
choline by magnetic resonance spectroscopy (MRS) and late enhancement curves by dynamic magnetic resonance imaging (DMRI) in determining therapeutic response to
neoadjuvant chemotherapy (NAC) among invasive
breast cancer patients. Subjects comprised 21 women (22 breasts) with biopsy-confirmed invasive
breast cancer (mean age 54 years) who underwent MRS with
choline and
gadolinium-enhanced DMRI at 1.5 T before and after NAC.
Choline signals on MRS were classified into 2 patterns:
choline-positive or
choline-negative, while late enhancement curves were classified as 'plateau' or 'washout' (type A), or 'persistent' (type B) according to the consensus of 2 radiologists. Maximum
tumor diameters and clinical
tumor reduction rates were assessed by MRI. Before NAC,
choline-positive results were found in all 22
tumors, 21 of which were type A and 1 of which was type B. After NAC, a change from
choline-positive to
choline-negative was observed with MRS in 11
tumors, while another 11 remained
choline-positive. According to DMRI, enhancement curves changed from type A to type B in 14
tumors, remained type A in 7
tumors, and remained type B in 1
tumor.
Tumor reduction rates were significantly greater for
choline-negative
tumors than for
choline-positive
tumors after NAC (p=0.0115). Following NAC, no significant correlation was noted between enhancement curves and reduction rates (p=0.1210), although a significant correlation was noted between enhancement curves and
choline signals (p=0.0014). Changes in
choline signals as noted using MRS might offer advantages over changes in enhancement curves by DMRI when evaluating response to NAC in terms of the
tumor reduction rate in invasive
breast cancer.