Objective: The predictive value of interim PET/computed tomography (I-PET/CT) in diffuse large B-cell lymphoma (DLBCL) is controversial. Our aim was to evaluate the predictive value of I-PET/CT for an event-free survival.
Patients and methods: We analyzed patients with DLBCL included in a prospective clinical trial who were treated with six cycles of dose-dense R-CHOP followed by pegfilgrastim and who had undergone an I-PET/CT (after two cycles) and a final PET [F-PET/CT (60 days after the sixth cycle)]. Event was defined as nonresponse, relapse, or death.
Results: A total of 69 patients were included. Their median age was 60 years; 54% were male, 25% had bulky disease, and 67% had an International Prognostic Index of 0–2. The median follow-up duration was 28.8 months. I-PET/CT was positive in 34 (49%) patients and F-PET/CT was positive in 12 (17.4%). The 3-year event-free survival was 86% for patients who were I-PET/CT negative as against 64% for those who were I-PET/CT positive (P=0.036). The negative and positive predictive values, sensitivity, and specificity of I-PET/CT for an event were 83, 32, 65, and 56%, respectively. In a multivariate analysis including baseline characteristics, I-PET/CT, and F-PET/CT, F-PET/CT was the only significant predictor (P<0.0005).
Conclusion: In patients with DLBCL treated with dose-dense R-CHOP plus pegfilgrastim, a negative I-PET/CT is highly predictive of a favorable outcome and a positive I-PET/CT is of limited clinical value. These results do not support treatment intensification after a short course of chemotherapy based solely on a positive I-PET/CT.
aLymphoma Unit, Department of Hematology, Institut Català d’Oncologia, Hospital Duran i Reynals, IDIBELL
bPET Unit, Institut of Diagnosis by Image (IDI)
cDepartment of Hematology, Hospital del Mar
dDepartment of Hematology, Institut Català d’Oncologia-Hospital, Hospital Germans Trias i Pujol, Barcelona
eDepartment of Hematology, University Hospital La Paz
fDepartment of Hematology, MD Anderson Hospital, Madrid
gDepartment of Hematology, University Hospital Donostia, Donostia
hDepartment of Hematology, Hospital Sont Llatzer, Palma de Mallorca
iDepartment of Hematology, University Hospital Santiago, Santiago de Compostela
jDepartment of Hematology, University General Hospital Morales Meseguer, Murcia
kDepartment of Hematology, General Hospital of Castellón, Castellón
lDepartment of Hematology, University Hospital Dr. Peset, Valencia
mDepartment of Hematology, University Hospital Clínico of Salamanca, Salamanca, Spain
Correspondence to Eva González-Barca, MD, PhD, Lymphoma Unit, Department of Hematology, Institut Catalá d’Oncología, Hospital Duran i Reynals, IDIBELL, Av. Gran Vía 199-203, 08908-L’Hospitalet de LLobregat, Barcelona, Spain Tel: +34 93 2607353; fax: +34 93 2607797; e-mail: firstname.lastname@example.org
Received February 22, 2013
Accepted May 31, 2013