Combined use of MRI and PET to monitor response and assess residual disease for locally advanced breast cancer treated with neoadjuvant chemotherapy.
OBJECTIVE
The purpose of the study was to evaluate the hypothesis that magnetic resonance imaging (MRI) and positron emission tomography (PET) are complementary and valuable in monitoring response and assessing residual disease of locally advanced breast cancer (LABC) treated with neoadjuvant chemotherapy. We sought to determine if the combination of the two modalities was more accurate than either alone and could provide better guidance in patient management.


METHODS
Sixteen lesions in 15 women with LABC were evaluated with MRI, PET, and clinical breast examination (CBE) before and after neoadjuvant chemotherapy. The pre- and posttherapy maximal tumor sizes on MRI and CBE and standard uptake values (SUVs) on PET served as the measurements for clinical response classification and residual disease assessment. Pathologic assessment provided the reference for macroscopic and microscopic pathologic tumor response and residual disease.


RESULTS
PET correctly predicted lack of pathologic response in five of six cases (83%); CBE predicted correctly in one of six (17%) cases, and MRI predicted correctly in zero of six cases. When PET predicted response, MRI defined the extent of macroscopic pathologic residual disease accurately in 9 of 10 cases (90%). When posttherapy MRI showed complete response (CR) in eight cases, macroscopic pathologic complete response (mCR) was observed in all eight cases (100%).


CONCLUSIONS
Our study suggests that combined use of MRI and PET is complementary and offers advantages over CBE. PET was more accurate in predicting pathologic nonresponse. Complete response by MRI correlated well with macroscopic pathologic complete response.
Chen
Xiaoming
X
Seattle Cancer Care Alliance, Seattle, WA 98109, USA. xchen@u.washington.edu
Moore
Mark O
MO
Lehman
Constance D
CD
Mankoff
David A
DA
Lawton
Thomas J
TJ
Peacock
Sue
S
Schubert
Erin K
EK
Livingston
Robert B
RB
D000293:Adolescent; D000328:Adult; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012189:Retrospective Studies