Prognosis estimation under the light of metabolic tumor parameters on initial FDG-PET/CT in patients with primary extranodal lymphoma
Article Category: Research Article
Published Online: Sep 08, 2016
Page range: 360 - 369
Received: Apr 20, 2016
Accepted: Jun 16, 2016
DOI: https://doi.org/10.1515/raon-2016-0045
© 2016 Radiol Oncol
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background
Non-Hodgkin’s lymphomas arising from the tissues other than primary lymphatic organs are named primary extranodal lymphoma. Most of the studies evaluated metabolic tumor parameters in different organs and histopathologic variants of this disease generally for treatment response. We aimed to evaluate the prognostic value of metabolic tumor parameters derived from initial FDG-PET/CT in patients with a medley of primary extranodal lymphoma in this study.
Patients and methods
There were 67 patients with primary extranodal lymphoma for whom FDG-PET/CT was requested for primary staging. Quantitative PET/CT parameters: maximum standardized uptake value (SUVmax), average standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to estimate disease-free survival and overall survival.
Results
SUVmean, MTV and TLG were found statistically significant after multivariate analysis. SUVmean remained significant after ROC curve analysis. Sensitivity and specificity were calculated as 88% and 64%, respectively, when the cut-off value of SUVmean was chosen as 5.15. After the investigation of primary presentation sites and histo-pathological variants according to recurrence, there is no difference amongst the variants. Primary site of extranodal lymphomas however, is statistically important (p = 0.014). Testis and central nervous system lymphomas have higher recurrence rate (62.5%, 73%, respectively).
Conclusions
High SUVmean, MTV and TLG values obtained from primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in primary extranodal lymphoma. SUVmean is the most significant one amongst them for estimating recurrence/metastasis.