[Comparison of findings with 18-FDG PET and CT in pretherapeutic staging of malignant lymphoma].
OBJECTIVE
Comparison of diagnostic efficiency of FDG-PET and CT regarding localisation, histology, size and FDG-uptake of a lesion.


METHODS
CT- and FDG-PET studies of 27 patients with histologically confirmed malignant lymphoma as primary disease or relapse were evaluated retrospectively. In CT lesions with a diameter (DCT) > 15 mm were regarded as positive. Focal accumulations of FDG, not explained by physiological metabolism, found by visual interpretation in iterative reconstructed PET-scans, were quantified for diameter (DPET) and corrected standardized uptake value (SUV), corrected for partial-volume-effect. Lesions were classified depending on histology and lesion quality (lymph nodes, bulks, extranodal lesions).


RESULTS
CT detected 78 lesions in 26 patients, all confirmed by FDG-PET. PET localized 18 additional lesions (+23%); in high grade NHL +25%. Both methods were equally efficient in cervical lymph nodes and lung lesions, in all other regions of lymphatic nodules and in case of liver and spleen lesions PET localized more lesions. SUV was significantly higher in high-grade NHL (19.0) than in low-grade NHL and Hodgkin's disease (10.6 resp. 11.1). DCT and DPET correlated significantly (r = 0.75).


CONCLUSIONS
Diagnostic efficiency of FDG-PET is equivalent or superior to CT in staging of malignant lymphoma before therapy. Qualitative interpretation seems sufficient for staging, quantitative analysis may add information about malignancy grade in NHL.
Thill
R
R
Klinik für Nuklearmedizin, Universitätsklinikum der RWTH Aachen, Deutschland. thill@nuk-gate.nukmed.rwth-aachen.de
Neuerburg
J
J
Fabry
U
U
Cremerius
U
U
Wagenknecht
G
G
Hellwig
D
D
Osieka
R
R
Günther
R
R
Büll
U
U
D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging / Q000473:pathology; D009367:Neoplasm Staging; D019275:Radiopharmaceuticals; D012008:Recurrence; D012044:Regression Analysis; D012189:Retrospective Studies; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18