Prognostic Value of Metabolic Parameters on Dedicated Breast Positron Emission Tomography in Luminal Breast Cancer

Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) measured using whole-body positron emission tomography (PET) have attracted attention as prognostic parameters. Dedicated breast PET (dbPET), a high-resolution imaging modality, is expected to accurately reflect the metabolic parameters of breast tumors. This study aimed to investigate the prognostic value of metabolic parameters on dbPET for breast cancer.

Ninety-six patients with luminal invasive breast cancer who underwent surgery were analyzed. SUVmax, MTV, and TLG were measured from dbPET images obtained before treatment. The associations between each parameter and recurrence-free survival (RFS) were evaluated.

During a median follow-up of 8.4 years, eight (8.3%) patients experienced recurrence. The median dbPET values were SUVmax 6.75, MTV 0.64 cm³, and TLG 2.56 cm³. Patients with high SUVmax, MTV, and TLG showed poorer RFS than those with low values: 8-year RFS was 81.9% vs. 96.3% for SUVmax (p=0.004), 68.8% vs. 96.0% for MTV (p<0.001), and 75.1% vs. 96.0% for TLG (p<0.001). Multivariate analysis identified high TLG [hazard ratio (HR)=7.81, 95% confidence interval (CI)=1.19-51.4, p=0.033] and lymphatic invasion (HR=6.64, 95% CI=1.05-41.9, p=0.044) as independent predictors of unfavorable RFS. Multiple regression models suggested that TLG was the most promising parameter for predicting RFS.

Metabolic parameters on dbPET, particularly TLG, are potentially useful for predicting the prognosis of luminal breast cancer.