Early treatment response evaluation in patients with diffuse large B-cell lymphoma--a pilot study comparing volumetric MRI and PET/CT.
OBJECTIVE
The purpose of this study is to evaluate the time course of early chemotherapy response in patients with aggressive non-Hodgkin's lymphoma (NHL) by magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT).


METHODS
Eight patients with histologically proven aggressive NHL were imaged by MRI and PET/CT before treatment (E1), 1 week (E2), and two cycles (E3) after chemotherapy.


RESULTS
The mean tumor volume on MRI was 276 mL at baseline; it decreased 58% at E2 (p < 0.05) and 65% further at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean maximum standardized uptake value (SUV(max)) of 20. The SUV(max) decreased 60% at E2 (p < 0.05) and 59% further at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden (mean 229 mL) decreased 66% at E2 (p < 0.05). The tumor volume on MRI correlated with the active tumor volume on fused PET/CT images in the same region of interest at both E1 and E2 (r = 0.88, p < 0.01, respectively).


CONCLUSIONS
Standard chemotherapy causes rapid decrease of both tumor metabolic activity and volume as early as 1 week, which continues to decline during therapy. Both volumetric MRI and PET/CT are valuable tools for early treatment response evaluation of aggressive NHL.
Wu
Xingchen
X
Department of Oncology, Tampere University Hospital, Tampere, Finland. Xingchen.Wu@uta.fi
Dastidar
Prasun
P
Pertovaara
Hannu
H
Korkola
Pasi
P
Järvenpää
Ritva
R
Rossi
Maija
M
Kööbi
Tiit
T
Eskola
Hannu
H
Kellokumpu-Lehtinen
Pirkko-Liisa
PL
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden