Midtreatment ¹⁸F-FDG PET/CT Scan for Early Response Assessment of SMILE Therapy in Natural Killer/T-Cell Lymphoma: A Prospective Study from a Single Center

Abstract

In a prospective study of newly diagnosed or relapsed histologically proven extranodal natural killer/T-cell lymphoma (ENKTL) patients, we aimed to determine the accuracy of midtreatment 18 F-FDG PET for response assessment using both visual and quantitative analyses. Methods: Twenty-four patients (12 men, 12 women; median age, 50 y; age range, 16-83 y) were referred for pre-, mid-(after 2-3 cycles of SMILE [prednisolone, methotrexate, ifosfamide, L-asparaginase, etoposide] chemotherapy), and end-treatment PET/CT scans (n 5 24, 24, and 17, respectively) using a standardized protocol. Sixty-five PET/CT scans were analyzed visually using the Deauville 5-point score (DS), and the lesion with the highest maximum standardized uptake value (SUV max ) was recorded. Survival curves were obtained using Kaplan-Meier analysis and compared using the log rank test, followed by multivariate analysis using the Cox proportional hazards model to assess the independent effects of International Prognostic Index (IPI) score (0-1 vs. 2-5), stage (stage I/II vs. stage III/IV), sex, DS (1-3 vs. 4-5), SUV max , and change in SUV max on overall survival (OS) and progression-free survival (PFS). The mean (±SD) follow-up period was 32 mo (±21 mo). Results: For 2-y OS, the following parameters were predictive: IPI score (P 5 0.047), DS at mid-and end-treatment (P , 0.001), and SUV max at mid-and end-treatment (P , 0.001 and 0.045, respectively). For 2-y PFS, the following parameters were predictive: sex (P 5 0.006), stage (P 5 0.034), IPI score (P 5 0.038), DS at mid-and end-treatment (P , 0.001 and 0.001, respectively), and SUV max at midtreatment (P 5 0.001). Multivariate analysis showed DS on mid-and end-treatment scans to be the only significant independent predictor of both OS (P 5 0.004 and 0.018, respectively) and PFS (P 5 0.004 and 0.014, respectively). The 2-y estimate for OS and PFS was 81% and 62%, respectively, in patients with a DS of 1-3, compared with 17% in patients with a DS of 4-5 (P , 0.001 and 0.001, respectively). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the midtreatment DS for prediction of OS and PFS were 63%, 94%, 83%, 83%, and 83%, respectively. Conclusion: Midtreatment PET/CT is a valuable tool for early treatment response assessment in extranodal natural killer/T-cell lymphoma patients.

NCCN Guidelines Insights: T-Cell Lymphomas, Version 2.2018

“…Recent reports from retrospective studies suggest that posttreatment PET/CT using the Deauville 5PS may be a valuable tool for response assessment in patients with newly diagnosed and R/R disease. [53][54][55] In a retrospective analysis of 102 patients with newly diagnosed ENKL, Deauville 5PS and EBV DNA after completion of initial treatment were independently associated with PFS and OS in the multivariable analysis. 54 Given the primarily extranodal sites of involvement often outside of the chest, abdomen, and pelvis, PET/CT is also preferred for followup to better assess these sites.…”

Prognostic relevance of pretransplant Deauville score on PET-CT and presence of EBV DNA in patients who underwent autologous stem cell transplantation for ENKTL

“…22 So far consensus has not been achieved on the positive and negative thresholds of Deauville five-point scale, recent studies have suggested the prognostic value of negative PET/CT response (DS 1-3) before ASCT for significant PFS and OS in patients with diffuse large B-cell lymphoma and follicular lymphoma. 23,24 In addition, for ENKTL patients, Khong et al 25 found that mid-treatment DS of 1-3 was a significant independent predictor of OS and PFS with 2-year OS and PFS rate of 81% and 62%, respectively. Our study used the cutoff value of Deauville score 1-2 to differentiate survival based on the statistical significance.…”

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach

“…Stage, surrogately detected by circulating EBV DNA plasma levels is of prognostic significance, [117][118][119] with chemoradiation regimens achieving 70-80% 5-year survival rates. 118,120 The outcome for plasmacytoma is better than multiple myeloma, with patients managed by localized radiation.…”