Prognostic importance of metabolic tumor parameters on initial FDG-PET/CT in patients with isolated infradiaphragmatic Hodgkin’s lymphoma

Background/Aim: Isolated infradiaphragmatic lymph node involvement is not common and makes up 5-13% of all stage I-II Hodgkin’s lymphoma. Important subjects about prognostic factors and optimal treatment of isolated infradiaphragmatic Hodgkin’s lymphoma has not been unveiled clearly. We aimed to evaluate the prognostic value of metabolic tumor indices on initial FDG-PET/CT over quantitative PET/CT parameters together with the classical predefined risk factors for patients with isolated infradiaphragmatic Hodgkin’s lymphoma in this study. Methods: This is a retrospective cohort study conducted between 2004 and 2015 including 21 patients for whom FDG-PET/CT were requested for primary staging. Quantitative PET/CT parameters (maximum standardized uptake value, average standardized uptake value, metabolic tumor volume and total lesion glycolysis) were used to estimate disease-free survival and overall survival. Results: Univariate cox regression was performed for all potential risk factors impacting metastasis/recurrence. Factors which had values of p<0.2 after univariate analysis (sex, age, stage, bulky disease, SUV max, SUV mean, MTV, TLG) were processed with multivariate model. Sex, TLG and bulky disease were found statistically significant after multivariate analysis. Conclusion: The existence of bulky disease at the diagnosis and high TLG values on primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in Hodgkin’s lymphoma with isolated infradiaphragmatic lymph node involvement.