Diagnostic performance of CT, PET, side-by-side, and fused image interpretations for restaging of non-Hodgkin lymphoma.
OBJECTIVE
The purpose of this study was to compare the diagnostic performance of positron emission tomography (PET) alone, computed tomography (CT) alone, side-by-side reading, and fused images for restaging or follow-up of patients with malignant lymphoma.


METHODS
Fifty patients with histologically confirmed non-Hodgkin lymphoma underwent an (18)fluoro-2-deoxyglucose (FDG)-PET scan, followed by a CT scan. CT alone, PET alone, side-by-side reading, and fused images were interpreted separately and visually using a five-point grading scale for the following eight regions: cervical, supraclavicular, axillary, mediastinal, para-aortic to iliac, mesenteric, inguinal, and extra-nodal. Diagnostic accuracy was compared on the basis of the final diagnoses determined by histological confirmation and/or clinical course.


RESULTS
For all regions combined, the interpretation of PET alone (sensitivity = 86.1%, specificity = 99.4%, accuracy = 91.0%), side-by-side reading (96.0%, 99.4%, 98.9%), and fused images (98.0%, 99.4%, 99.2%) yielded significantly higher diagnostic performance than that of CT alone (59.4%, 96.1%, 91.0%; P < 0.001). The cervical, supraclavicular, and extra-nodal regions were more accurately diagnosed with PET (P < 0.05), whereas the para-aortic to iliac regions were diagnosed more accurately with side-by-side reading and fused images than with CT alone or PET alone (P < 0.05).


CONCLUSIONS
Although fused images are clinically valuable, side-by-side reading showed equivalent performance, whereas the interpretation of PET alone yielded reasonably high diagnostic performance for restaging or follow-up of patients with malignant lymphoma.
Nogami
Munenobu
M
Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. aznogami@med.kobe-u.ac.jp
Nakamoto
Yuji
Y
Sakamoto
Setsu
S
Fukushima
Kazuto
K
Okada
Tomohisa
T
Saga
Tsuneo
T
Higashi
Tatsuya
T
Senda
Michio
M
Matsui
Toshimitsu
T
Sugimura
Kazuro
K
D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*