Prognostic and Treatment Values of Baseline Metabolic Tumor Volume in Early-stage Extranodal NK/T-cell Lymphoma in the Modern Treatment Era.

Abstract

To investigate the prognostic and treatment values of maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) in early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL). MTV and SUVmax of the primary tumor in 122 patients with early-stage ENKTCL were measured. The prognostic capacity of MTV and SUVmax and their implications for treatment selection were evaluated. Potential mechanisms of MTV and SUVmax were evaluated through transcriptome analysis of tumors in 16 patients. Patients with high-SUVmax or large-MTV were more likely to have adverse clinical factors. Both SUVmax and MTV were associated with overall survival (OS) in univariate analysis (P = 0.029 and 0.001, respectively). MTV was independently associated with OS (P = 0.027), and mediation analysis suggested that distant metastasis statistically accounted for 98.2% of this association. In the intermediate- and high-risk early-stage subgroup, patients with MTV < 50 mL had significantly better OS and progression-free survival (PFS) (both P = 0.002) than those with MTV ≥ 50 mL, but showed survival outcomes comparable to low-risk early-stage patients. Furthermore, radiotherapy and combined-modality therapy (CMT) yielded comparable PFS (P = 0.268) and OS (P = 0.570) in patients with MTV < 50 mL. In contrast, for patients with MTV ≥ 50 mL, CMT resulted in better PFS and OS (both P < 0.001) compared to RT alone. MTV is an independent metabolic predictor of survival and may identify patients who are more likely to benefit from CMT in early-stage ENKTCL. Further prospective validation is warranted.