Comparative study of quantitative scales for the evaluation of treatment response in Hodgkin lymphoma

Abstract

Hodgkin lymphoma (HL) is a type of blood cancer that generally originates in the lymph nodes and can spread within the lymphatic system. HL is highly curable and treated usually by chemotherapy following the ABVD (Adrymacin, Bleomycin, Vinblastine and Dacarbazine) regime. The evaluation of the response to the treatment of the patients is performed by the visual analysis of interim and end-of-treatment 18Ffluorodeoxyglucose (FDG) positron emission tomography (PET) images. The Deauville five-point scale is the internationally recommended tool to assess patient response. However, this scale is based on a visual analysis of PET-FDG images. Semiquantitative scales, called rPET and qPET that are based on the Standardized Uptake Value (SUV), have previously been proposed for a more objective classification of the cases. A graphical user interface is developed to manually select the lesions in PET images, process the images and automatically calculate the Deauville score based on the rPET and qPET scales. The algorithm is validated by analysing 9 cases of patients diagnosed with HL. The obtained Deauville scores are compared to the evaluation of the images by two physicians specialized in nuclear medicine. In 94.44% and 100% of the cases that are classified with the rPET and qPET scales, respectively, the result matches the visual analysis. The results obtained with both parameters could potentially indicate their viability in assessing the response to treatment in HL patients.