Prognostic value of interim ¹⁸F-FDG PET/CT in patients with natural killer/T cell lymphoma

Objective: To investigate the prognostic, value of interim ¹⁸F-FDG PET/CT scan in parents with natural killer (NK)/T cell lymphoma. Methods: From January 2012 to May 2015, thirteen patients (10 males, 3 females; mean age (43.85 ± 7.66) years) underwent methotrexate + ifosfamide + etoposide + prednisone acetate + L-asparaginase (SMILE) chemotherapy. All patients underwent pre-, mid-treatment (after 3 cycles of SMILE) PET/CT scan, and 9 of them further underwent end-treatment (after 6 cycles of SMILE) PET/CT scan. View analysis and ΔSUV_max(%) were used to interpret ¹⁸F-FDG PET/CT images. Two-sample t test was used to analyze the difference of ΔSUV_max between PEX/CT positive group and PET/CT-negative group. Survival curves were obtained using Kaplan-Meier analysis. OS and PFS were calculated and compared with the log-rank test. Results: All 13 patients underwent ¹⁸F-FDG PET/CT imaging after 3 chemotherapy cycles and were divided into PET/CT-negative group (7 patients) and positive group (6 patients). ΔSUV_max of the negative group was higher than that of the positive group: (65.73 ± 5.95)% vs (52.50 ± 1.49)%; t = 4.199, P < 0.05. Median follow-up period was 26 (9-48) months. The median PFS and median OS of PET/CT-negative group were higher than those of PET/CT-positive group (39 vs 18 months, 44 vs 24 months; χ² = 4.521, 4.829, both P < 0.05). Conclusion: Interim PET/CT scan could predict the outcome of patients with NK/T cell lymphoma. (authors)