Naomi Nakajima

Volume-based parameters of 18F-fluorodeoxyglucose positron emission tomography/computed tomography improve disease recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive axillary lymph nodes.

PURPOSE To determine whether volume-based parameters on pretreatment (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in breast cancer patients treated with mastectomy without adjuvant radiation therapy are predictive of recurrence. METHODS AND MATERIALS We retrospectively analyzed 93 patients with 1 to 3 positive axillary nodes after surgery, who were studied with (18)F-fluorodeoxyglucose positron emission tomography/computed tomography for initial staging. We evaluated the relationship between positron emission tomography parameters, including the maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinical outcomes. RESULTS The median follow-up duration was 45 months. Recurrence was observed in 11 patients. Metabolic tumor volume and TLG were significantly related to tumor size, number of involved nodes, nodal ratio, nuclear grade, estrogen receptor (ER) status, and triple negativity (TN) (all P values were <.05). In receiver operating characteristic curve analysis, MTV and TLG showed better predictive performance than tumor size, ER status, or TN (area under the curve: 0.85, 0.86, 0.79, 0.74, and 0.74, respectively). On multivariate analysis, MTV was an independent prognostic factor of locoregional recurrence-free survival (hazard ratio 34.42, 95% confidence interval 3.94-882.71, P=.0008) and disease-free survival (DFS) (hazard ratio 13.92, 95% confidence interval 2.65-103.78, P=.0018). The 3-year DFS rate was 93.8% for the lower MTV group (<53.1; n=85) and 25.0% for the higher MTV group (≥53.1; n=8; P<.0001, log-rank test). The 3-year DFS rate for patients with both ER-positive status and MTV<53.1 was 98.2%; and for those with ER-negative status and MTV≥53.1 it was 25.0% (P<.0001). CONCLUSIONS Volume-based parameters improve recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive nodes. The addition of MTV to ER status or TN has potential benefits to identify a subgroup at higher risk for recurrence.