The Role of¹⁸F-FDG PET/CT for Initial Staging of Nasal Type Natural Killer/T-Cell Lymphoma: A Comparison with Conventional Staging Methods

Abstract

The utility of 18 F-FDG PET/CT in patients with nasal-type natural killer (NK)/T-cell lymphoma has not been established. Therefore, we evaluated the role of 18 F-FDG PET/CT for determining cancer staging by comparing its results to those of conventional staging methods (CSMs) (physical examination, CT with intravenous contrast, biopsies from primary sites, and bone marrow examinations) in patients with nasal-type NK/T-cell lymphoma. Methods: In this study, 52 consecutive patients (34 men, 18 women; mean age, 49.4 y) with newly diagnosed nasal-type NK/T-cell lymphoma were studied. Anatomic regions (n 5 1,300; 16 nodal and 9 extranodal regions per patient) were assessed with an 18 F-FDG PET/CT scan and with CSMs, and each anatomic region was classified as positive or negative for malignancy. Biopsy and clinical follow-up, including additional imaging studies, were used as the gold standard for diagnosis. Results: Of the 59 nodal and 71 extranodal anatomic regions that were truly positive for malignancy, 18 F-FDG PET/CT detected 58 nodal and 69 extranodal. CSMs, however, detected only 44 of the nodal and 61 of the extranodal anatomic regions that were positive for malignancy (nodal comparison of PET/CT vs. CSMs, P , 0.001; extranodal comparison of PET/CT vs. CSMs, P 5 0.008). PET/CT scans exhibited a significantly better sensitivity (97.7% vs. 80.7%, P , 0.001) than CSMs for the detection of malignant lesions. PET/CT findings altered the original staging category for 12 patients (21.2%) and affected treatment planning in 23 cases (44.2%). Conclusion: Our study demonstrated that 18 F-FDG PET/CT scanning is a valuable modality for staging and treatment planning in patients with nasal-type NK/T-cell lymphoma.

Imaging of Non-Hodgkin Lymphomas: Diagnosis and Response-Adapted Strategies

“…Nasal-type NK/T-cell lymphoma is most often a disease localized to the head-and-neck region, but PET/CT staging will change stage in one fifth of these patients, and in few patients, disseminated disease is found by PET/CT. Change of treatment by PET/CT in nasal-type NK/T-cell lymphomas is even more common as PET/CT [often accompanied by magnetic resonance imaging (MRI)] modifies radiotherapy planning in many cases [36].…”

Midtreatment 18F-FDG PET/CT Scan for Early Response Assessment of SMILE Therapy in Natural Killer/T-Cell Lymphoma: A Prospective Study from a Single Center

“…Because of the rarity of the disease, published experience and recommendations on the role of 18 F-FDG PET in ENKTL are limited. The few reports in the literature have found ENKTL to be consistently 18 F-FDG-avid, with PET superior to conventional cross-sectional imaging and therefore useful in disease staging (3)(4)(5)(6). The mean 18 F-FDG uptake measured by maximum standardized uptake value (SUV max ) was found to be significantly higher in the more common B-cell lymphomas than in indolent B-cell lymphomas and significantly lower than in aggressive B-cell lymphomas (7).…”

Utility of baseline, interim and end-of-treatment 18F-FDG PET/CT in extranodal natural killer/T-cell lymphoma patients treated with L-asparaginase/pegaspargase

“…The few current studies on B-PET in ENKL are mostly focused on diagnosis and staging2425. In this study, we examined the prognostic value of baseline SUVmax, WBMTV and WBTLG.…”