Utility of baseline, interim and end-of-treatment 18F-FDG PET/CT in extranodal natural killer/T-cell lymphoma patients treated with L-asparaginase/pegaspargase

Abstract

Positron emission tomography-computed tomography (PET/CT) is widely used for initial staging and monitoring treatment responses in Hodgkin and diffuse large B-cell lymphoma. However, its prognostic value in extranodal natural killer (NK)/T-cell lymphoma (ENKL) remains unclear. Here, we conducted a retrospective study to determine the impact of PET/CT in ENKL. Fifty-two patients newly diagnosed with ENKL were enrolled. Baseline maximum standardized uptake values (SUVmax), whole-body metabolic tumor volume (WBMTV) and whole-body total lesion glycolysis (WBTLG) were recorded. Additionally, interim PET/CT (I-PET) and end-of-treatment PET/CT (E-PET) results were scored using a 5-point scale. Patients were divided into groups using baseline parameter cut-off values; significant differences were found in overall survival (OS) and progression-free survival (PFS) between the high and low WBMTV and WBTLG groups and in OS between the two SUVmax groups. Positive I-PET and E-PET results predicted inferior PFS and OS. A multivariate analysis showed that baseline WBTLG, I-PET and E-PET results were associated with PFS and OS, and baseline SUVmax was an independent predictor of OS. Thus, baseline WBTLG, I-PET and E-PET results are good predictors of PFS and OS in ENKL patients who received L-asparaginase/pegaspargase in their first-line treatment, and baseline SUVmax is a valuable tool for assessing OS.

Prognostic value of baseline, interim and end-of-treatment 18F-FDG PET/CT parameters in extranodal natural killer/T-cell lymphoma: A meta-analysis

“…The median follow-up time ranged from 19 to 45 months. Five studies [ 22 – 23 , 27 – 29 ] focused on the prognostic value of B-PET/CT, three studies [ 22 , 24 – 25 ] addressed the prognostic value of I-PET/CT performed during the 4 weeks after initial treatment, and three studies [ 21 – 22 , 26 ] revealed the prognostic value of E-PET/CT performed after the final treatment with an interval of 3–4 weeks. Liang et al [ 23 ] used WB3SUVmax, which represents the whole body SUVmax of 3 nodal regions (superior diaphragm, inferior diaphragm and spleen) and 10 extranodal regions (upper aero-digestive tract, skin/subcutaneous tissues, central nervous system and spinal cord, lung, myocardium, bone and bone marrow, bowel, kidney and adrenals, liver and testis) as prognostic factors.…”

“…Six studies [ 22 – 23 , 27 – 29 ] revealed the value of B-PET/CT in evaluating the prognosis for ENKTL. SUV max [ 22 – 23 , 27 – 28 ], MTV [ 22 , 27 , 29 ] and TLG [ 22 , 27 ] were used to predict PFS and OS. For SUV max , the HRs for PFS and OS were 2.78 (95% CI 1.54–5.03, p = 0.0007; χ 2 = 3.81, P = 0.28, I 2 = 21%) ( Fig 2A ) and 4.78 (95% CI 2.29–9.96, p<0.0001; χ 2 = 0.31, P = 0.96, I 2 = 0%) ( Fig 2B ), respectively.…”

“…Regarding the I-PET/CT parameters, three studies [ 22 , 24 – 25 ] using DS were available, with HRs for PFS and OS of 5.15 (95% CI 2.71–9.80, p<0.00001; χ 2 = 1.13, P = 0.57, I 2 = 0%) ( Fig 3A ) and 5.80 (95% CI 2.28–14.73, p = 0.0002; χ 2 = 1.58, P = 0.45, I 2 = 0%) ( Fig 3B ), respectively, indicating a significant association between a positive DS in I-PET/CT and poor PFS and OS. Three studies [ 21 – 22 , 26 ] were available regarding the DS on E-PET/CT, with HRs for PFS and OS of 3.65 (95% CI 2.13–6.26, p<0.00001; χ 2 = 0.02, P = 0.99, I 2 = 0%) ( Fig 3C ) and 3.32 (95% CI 1.79–6.15, p = 0.0001; χ 2 = 0.38, P = 0.83, I 2 = 0%) ( Fig 3D ), respectively, suggesting that a positive DS in E-PET/CT predicted worse survival.…”

“…Several studies have shown that baseline SUV max can be a predictor of the treatment response and survival rate in ENKTL, which is consistent with our meta-analysis results [ 31 – 32 ]. Chang et al [ 22 ] reported that a high SUV max was an independent predictor of OS but not PFS. Conversely, Kim et al [ 27 ] reported that a high B-PET SUV max was a significant predictor of PFS but not OS.…”

Baseline SUVmax of 18F-FDG PET-CT indicates prognosis of extranodal natural killer/T-cell lymphoma

“…For these patients, the prognostic value of SUVmax was also verified by several researches. Chang et al [ 21 ] analyzed 52 stage I to IV extranodal NKTCL patients and found that baseline SUVmax > 15.1 was a poor predictor for OS independent of other clinical features but not for PFS.…”