[Application of 18F-FDG PET/CT images in the newly diagnosed extranodal NK/T cell lymphoma].

Objective: This study was to explore the use value of (18)F-FDG PET/CT in patients with extranodal NK/T cell lymphoma (ENKTL).

Methods: Both PET/CT and CT images were retrospectively analyzed in 43 newly diagnosed patients with ENKTL, and the anatomical position, extent of foci, subtypes, staging and therapeutic regimen determined by both these 2 imaging methods were compared, and relationship between the maximum standard uptake value (SUV(max)) and subtypes, different staging and constitutional symptoms were evaluated.

Results: The top four anatomical positions involved were nose (76.74%), pharynx nasalis (41.86%), Waldeyer's ring (30.23%) and paranasal sinus (27.91%), respectively according to the results of the PET/CT examination, and (18)F-FDG uptake was not found in four patients in the region of upper aerodigestive tract. The PET/CT staging was significantly correlated with constitutional symptoms (P < 0.01). The mean SUV(max) of 43 patients was 13.65 ± 6.35, and the SUV(max) of advanced stages (III/IV) was higher than that of early stage (I/II). Different staging results were found in 21 patients between PET/CT and CT images, 14 patients out of them had direct influence on the treatment plan. Staging of 8 cases was changed from early stage judged by CT image into advaneed stage judged by PET/CT, and radiotherapy regimen of 6 cases at early stage were altered because of the application of PET/CT.

Conclusion: The location and scope of foci in ENKTL patients can be displayed more accurately by PET/CT, the PET/CT is more accurate and reliable than traditional CT image, and has considerable value in determining the treatment plan, and it should be applied in clinical practice widely.