Therapeutic evaluation and prognostic value of interim hybrid PET/CT with (18)F-FDG after three to four cycles of chemotherapy in non-Hodgkin's lymphoma.
OBJECTIVE
Modern risk-adapted treatment requires accurate assessment of the patient's prognosis. This study assessed the value of hybrid PET/CT with 2-[18F]fluoro-2-deoxy-d-glucose ((18)F-FDG) after 3-4 cycles of chemotherapy for early evaluation of response to therapy and prediction of progression-free survival (PFS) in non-Hodgkin's lymphoma (NHL).


METHODS
Sixty-one consecutive NHL patients (37 male and 24 female) were included. The (18)F-FDG hybrid PET/CT scans were performed prior to chemotherapy (initial scan) and after 3-4 cycles of chemotherapy (interim scan). Interim FDG findings were correlated to the PFS using Kaplan-Meier analysis. Regression analyses were employed to test for independence of established pretreatment prognostic factors.


RESULTS
After 3-4 cycles of chemotherapy, positive (18)F-FDG lesions were found in 28 patients, minimal residual uptake (MRU) in 8 and negative scans in 25 patients. In FDG-positive group, 22 patients showed progress and three died. Nine (18)F-FDG-negative patients and 4 patients from the MRU group relapsed. Survival analyses showed highly significant associations between early interim FDG imaging and PFS (P < 0.0005). The 2-year PFS rate for FDG-negative patients was 72.2 and 23.0% for FDG-positive patients. The regression model showed that the predictive value of FDG imaging owed its significance to the very high hazard ratio between patients with positive FDG imaging and patients with negative FDG imaging (P < 0.001).


CONCLUSIONS
Early interim FDG imaging is an excellent and independent predictor of PFS in NHL. An early assessment of chemotherapy response with FDG scans may provide useful information for selection of patients for alternative therapeutic strategies.
Zhao
Jinhua
J
Department of Nuclear Medicine, The First People's Hospital, Shanghai Jiaotong University, Shanghai, People's Republic of China. zjh1963@gmail.com
Qiao
Wenli
W
Wang
Chun
C
Wang
Taisong
T
Xing
Yan
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D016019:Survival Analysis; D014055:Tomography, Emission-Computed / Q000379:methods*
D019788:Fluorodeoxyglucose F18