PET/CT-based bone-marrow assessment shows potential in replacing routine bone-marrow biopsy in part of patients newly diagnosed with extranodal natural killer/T-cell lymphoma.

Purpose: This study aimed to determine the potential of positron emission tomography/computed tomography (PET/CT) in replacing routine bone-marrow biopsies (BMB) in newly diagnosed extranodal natural killer/T-cell lymphoma (ENKTCL).

Methods: Newly diagnosed patients underwent PET/CT imaging and routine BMB to assess bone/bone marrow involvement (BMI). Clinical stage and treatment plan were determined, and survival was compared.

Results: In a total of 101 patients, 78 were diagnosed as stage I/II and 23 as stage III/IV without using the BMB results. No BMB-positive patients were identified in stages I/II, and therefore, the BMB results did not alter the stage and treatment choice in any patients. The sensitivity and specificity of focal skeletal PET/CT lesion(s) in assessing BMI was 100% and 92.8%, respectively, taking routine BMB as the reference standard. The overall survival (OS) and progression-free survival (PFS) of BMB-positive patients was significantly inferior (P = 0.0011 and 0.0465, respectively, in advanced-stage patients; both P < 0.0001 in all patients), and this was corroborated by the PET/CT findings (P = 0.0006 and 0.0116, respectively, in advanced-stage patients; both P < 0.0001 in all patients).

Conclusions: Based on the results, PET/CT demonstrated satisfactory predictive performance in terms of staging and prognosis in ENKTCL. BMB did not influence staging and treatment in newly diagnosed ENKTCL, and routine non-targeted BMB is not obligatory for early stage patients undergoing PET/CT. Targeted BMB is recommended to confirm BMI in advanced-stage patients.