Diagnostic accuracy of PET/CT in patients with extranodal marginal zone MALT lymphoma.
BACKGROUND
(18)Fluoro-2-deoxyglucose ((18)FDG) positron emission tomography (PET) is widely used for initial staging and follow-up in patients with malignant lymphoma. While earlier studies suggested a limited role for PET in extranodal marginal zone mucosa-associated lymphoid tissue (MALT) lymphoma patients due to their non-FDG avidity, more recent reports have suggested that the issue is controversial. In the present study, we evaluated the diagnostic accuracy of PET integrated with CT (PETCT) in patients with MALT lymphoma and assessed its reliability in clinical staging and monitoring response.


METHODS
Thirty-three patients with biopsy proven MALT lymphoma in 37 sites, who underwent PET/CT at diagnosis, were enrolled. Medical records, PET/CT findings and data obtained by other diagnostic procedures were reviewed.


RESULTS
Common sites of MALT lymphoma were the stomach (18), lung (5), orbit (4), and parotid gland (3). PET/CT detected active disease in 18 of 33 patients (54.5%) at diagnosis. Sensitivity in gastric MALT (38.9%) was lower when compared with non-gastric MALT (75%). PET/CT detected active disease in 100% patients with advanced disease (stage III-IV) but only in 42.3% with early stage disease (I-II). The incidence of gastric FDG uptake was higher in patients showing gastric ulcer on gastroscopy than in subjects with minimal or no macroscopic findings. Of the 33 patients in the study cohort, 12 had a follow-up PET/CT which detected relapse in three patients.


CONCLUSIONS
These data suggest that PET/CT is a useful tool for both, initial staging and follow-up after therapy in patients with MALT lymphoma. Its sensitivity depends on disease location and stage at initial diagnosis.
Institute of Hematology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. chavap@tasmc.health.gov.il
Chava
C
Perry
Yair
Y
Herishanu
Ur
U
Metzer
Osnat
O
Bairey
Rosa
R
Ruchlemer
Leonor
L
Trejo
Elizabeth
E
Naparstek
Einat Even
EE
Sapir
Aaron
A
Polliack
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000592:standards*; D012008:Recurrence; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000592:standards*
D019788:Fluorodeoxyglucose F18