Prognostic value of metabolic tumour volume and total lesion glycolysis in 18 F-FDG PET/CT scans in locally advanced breast cancer staging.

OBJECTIVE: To determine whether metabolic tumour volume (MTV) and total lesion glycolysis (TLG) are able to predict recurrence risk in locally advanced breast cancer (LABC) patients.

MATERIAL AND METHODS: Retrospective study of LABC patients who undertook neoadjuvant, local and adjuvant treatment and follow up. A18 F-FDG PET/CT study for initial staging was performed analysing in this study different metabolic parameters (MTV, TLG, SUVmax and SUVmed) both in the primary tumour (T) as well as in axillary nodes (N) and whole-body (WB).

RESULTS: Forty females were included between January 2010-2011; follow up until January 2015 was completed. The average follow-up was 46 months. Twenty percent presented recurrence: local disease (n=2) and distant metastasis (n=6); 3 patients died (38% of the patients which recurred and 7.5% from the total). SUVmax, MTV and TLG, in T, N and WB, were higher in those patients with recurrence. The MTV and TLG parameters in the tumour (T) were related to the recurrence rate (P=.020 and P=.028, respectively); whereas SUVmax in the lymph nodes (N) was significantly related (P=.008) to the recurrence rate. The best cut-off points to predict recurrence where: MTV T ≥19.3cm3 , TLG T≥74.4g and SUVmax N≥13.8, being 10-12 times more likely to recidivate when these thresholds where exceeded. Tumour grade was the only clinical-pathological variable which was related to recurrence probability (p=.035).

CONCLUSIONS: In this study of LABC patients the metabolic parameters which have a better relationship with recurrence rate are: MTV and TLG in the primary tumour, SUVmax in the regional lymph node disease and whole-body PET data.