The exact Deauville score, NABS score and high SUVmax predicts outcome in extranodal natural killer/T-cell lymphoma

Objective Natural killer T-cell lymphoma (NKTCL) is an aggressive type of non-Hodgkin’s lymphoma. While FDG-PET/CT imaging has been increasingly utilized for disease assessment, its prognostic value and potential utility in NKTCL patient stratification remain controversial. We aim to investigate the prognostic utility of FDG-PET/CT and its role in complementing clinical indices. Methods We conducted a retrospective review of 72 patients from a tertiary National Cancer Centre with biopsy-proven NKTCL and available FDG-PET/CT data (either baseline, end of treatment or both). Survival analysis was performed using the Kaplan–Meier method and multivariable Cox proportional regression. Results High initial SUVmax was significantly associated with advanced Ann-Arbor stage ( p = 0.0352), elevated LDH levels ( p = 0.0059) and plasma EBV DNA detection ( p = 0.0278). SUVmax correlated with worse progression-free survival (PFS) (HR 3.68, 95% CI 1.56–8.69, p = 0.0030) and a trend toward worse overall survival (OS) (HR 2.06, 95% CI 0.95–4.45, p = 0.0676). End of treatment Deauville scores of 4–5, as compared to scores of 1–3, was associated with worse PFS (HR 2.72, 95% CI 1.04–7.12, p = 0.0419). Notably, while all patients with scores of 5 developed progressive disease, only 2 of 5 patients with scores of 4 eventually relapsed. Clinical indices (NABS score) were still able to stratify survival outcomes regardless of end-of-treatment Deauville scores. Conclusions A Deauville score of 5 is more diagnostic of true disease progression than a score of 4, and NABS score may be used in patients who achieve Deauville scores of 1–3 for further risk stratification. A higher SUVmax at baseline portends a worse prognosis in NKTCL.