CT and 18F-FDG PET for noninvasive detection of splenic involvement in patients with malignant lymphoma.
OBJECTIVE
The purpose of this study was to determine the sensitivity and specificity of (18)F-FDG PET, CT, and combined PET/CT in the detection of splenic involvement at initial staging of lymphoma.


METHODS
A retrospective longitudinal analysis was performed on the records of 111 patients with proven lymphoma who had undergone PET and CT before and after treatment. CT scans were evaluated independently by two radiologists, and PET scans by two nuclear medicine physicians. Abnormal CT findings were defined as low-attenuation nodules or a splenic index greater than 725 cm(3) (> 2 SDs above the mean in 100 controls). An abnormal PET finding was defined as splenic uptake greater than hepatic uptake. True splenic involvement was defined retrospectively on the basis of the treatment response assessed with criteria revised in the International Harmonization Project on lymphoma. Observer agreement and sensitivity and specificity values were calculated.


RESULTS
Observer agreement for CT splenic index and PET findings was good. For initial splenic staging, the sensitivity and specificity of CT, PET, and PET/CT were 91% and 96%, 75% and 99%, and 100% and 95%.


CONCLUSIONS
For initial staging of splenic involvement in malignant lymphoma, the sensitivity and specificity of PET/CT can reach 100% and 95%. The sensitivity of the combined approach is higher than that of either technique alone.
de Jong
Pim A
PA
Department of Radiology and Nuclear Medicine, Meander Medisch Centrum, Lichtenberg, Amersfoort, The Netherlands. pimdejong@gmail.com
van Ufford
Henriette M Quarles
HM
Baarslag
Henk-Jan
HJ
de Haas
Marie J
MJ
Wittebol
Shulamiet H
SH
Quekel
Lorentz G
LG
de Klerk
John M
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008137:Longitudinal Studies; D008223:Lymphoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018579:Patient Selection; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013160:Splenic Neoplasms / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18