229P - Dedicated breast PET to predict pathological complete response after neoadjuvant chemotherapy for breast cancer.

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Breast Cancer, Locally Advanced
Breast Cancer
Imaging, Diagnosis and Staging
Presenter Makoto Fujiwara
Citation Annals of Oncology (2017) 28 (suppl_5): v68-v73. 10.1093/annonc/mdx364
Authors M. Fujiwara, N. masumoto, S. Sasada, T. Kadoya, M. Okada
  • Surgical Oncology, Hiroshima University, 734-8551 - Hiroshima/JP

Abstract

Background

Reports indicate that whole-body (WB) 18F-fluorodeoxyglucose (FDG) PET can predict a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). New dedicated breast PET (DBPET) can generate high-resolution images and thus might be able to predict pCR after NAC. The present study aimed to determine whether or not DbPET can predict the effects of NAC for breast cancer more effectively than WBPET.

Methods

The clinical responses of 35 consecutive patients with breast cancer (T1–4, N0–1, M0) who underwent NAC between January 2016 and January 2017 were assessed using WBPET and DBPET. We assessed maximum standardized uptake values (SUVmax), before (pre-SUVmax) and after (post-SUVmax) NAC and rates of change in SUVmax (ΔSUVmax) before and after NAC. Relationships between these parameters and pathological responses (pCR) were assessed using each modality. We created receiver operating characteristics curves (ROC), calculated areas under them (AUC) for both WBPET and DBPET images and predicted pCR.

Results

Twelve of 35 patients achieved pCR. The median pre-SUVmax, post-SUVmax and ΔSUVmax among the 35 patients determined using WBPET and DBPET were 6.8 and 18.0, 1.7 and 3.1, and 78.2 and 77.6, respectively. Uptake of 18F-FDG was indistinguishable from background in WBPET, but confirmed in DBPET after NAC in three of 23 patients with non-pCR disease. The median pre-SUVmax of WBPET and DBPET in the pCR group was higher than non-pCR group (7.88 and 21.73 vs 6.22 and 16.28, p = 0.30 and p = 0.15, respectively). In contrast, post-SUVmax of the pCR group was lower than non-pCR group (0.97 and 2.06 vs 1.54 and 3.86, p = 0.062 and p = 0.032, respectively). ΔSUVmax of pCR group was higher than non-pCR group (82.23 and 88.56 vs 76.34 and 72.55, p = 0.27 and p = 0.04, respectively). Additionally, the AUC of DBPET (pre-SUVmax: 0.543, post-SUVmax: 0.725, ΔSUVmax: 0.752) was higher than WBPET (pre-SUVmax: 0.477, post-SUVmax: 0.694, ΔSUVmax: 0.549) in either time points.

Conclusions

The diagnostic accuracy of DBPET were equal to, or better than those of WBPET. DBPET might serve as a new diagnostic modality when planning therapeutic strategies for patients with breast cancer after neoadjuvant chemotherapy.

Clinical trial identification

Legal entity responsible for the study

Hiroshima University

Funding

None

Disclosure

All authors have declared no conflicts of interest.