features of imaging of different types of hodgkin’s lymphoma using combined positron emission and computed tomography

Background & Aims. At present, PET-CT has an important clinical significance in Hodgkin’s lymphoma (HL) and is used both for initial tumor staging and restaging and for the evaluation of treatment efficacy. Published data indicate the possible lack of radiotracer accumulation in the tumor tissue in HL before primary treatment. A low metabolic activity of the tumor tissue prior to treatment makes it difficult to assess the treatment dynamics during the anti-tumor therapy. The aim of this work is to determine the incidence of the low metabolic activity of tumor tissue in HL. Methods. Findings of 131 18F-fluorodeoxyglucose (FDG) whole body PET-CT scans of patients with histologically verified HL (over the period from 2011 to 2015) were studied retrospectively. Patterns of FDG accumulation in different histological types of HL, as well as the levels of metabolic activity in patients with tumor-related toxicity symptoms (B-symptoms) were studied. Results. The low metabolic activity was detected in 4 % of patients with de novo HL. The highest levels of metabolic activity were detected in nodular sclerosis and the lowest ones in nodular lymphocyte-predominant HL. Higher levels of radiotracer metabolic activity were observed in patients with general symptoms. Conclusion. In general, a high metabolic activity of the neoplasm is typical for HL. Primary staging before the treatment should be performed for a more accurate evaluation of dynamics of HL treatment outcomes, because in a number of cases a baseline low FDG accumulation in the neoplasm may imitate the absence of a viable tumor tissue in the affected lymph nodes at assessment of treatment results.