Update of Assessment of Early Response Using PET/CT in Malignant Lymphoma.

M, Mattar,; H, Moustafa,

doi:10.21608/egyjnm.2021.172721

Update of Assessment of Early Response Using PET/CT in Malignant Lymphoma.

Document Type : Review Article

Authors

Mattar, M ¹
Moustafa, H ²

¹ Nuclear Medicine Unit, National Cancer Institute, Egypt.

² Nuclear Medicine Unit, Faculty of Medicine, Cairo University, Egypt.

10.21608/egyjnm.2021.172721

Abstract

18F-FDG PET/CT is an eminent widely used diagnostic imaging modality utilized for staging and evaluating therapy response in malignant lymphomas. The pre-eminence of 18F-FDG PET/CT over CT to recognize viable lymphomatous tissue after two cycles of chemotherapy cycles has lately directed to reconsideration of criteria of early therapy response.
Numerous recent researches have also confirmed that early response assessment within early two to three chemotherapy cycles is mandatory to evaluate chemo sensitivity and may have the potential to guide additional risk-adapted treatment modalities in malignant lymphoma patients.
Early response evaluation depends mostly upon quantitative Deauville criteria which may subjective dichotomous interpretation if evaluated by more than one interpreter. Therefore, assessment of therapy response might necessitate a more objective quantification methodology of 18F-FDG uptake alterations. Standardized uptake value (SUV) is currently the most regularly used semi-quantitative parameter allowing non-invasive evaluation of 18F-FDG metabolic rate.
Novel Volume based parameters as MTV and TLG have recently gained researchers attention as they are considered more representative of total tumour burden than single voxel based parameter; SUV. They may have the potential for early prediction of therapy response, prognosis of clinical outcome, and tumour delineation for radiotherapy planning. However, lack of standard method for tumour segmentation hinders the routine use of more inclusive volume based parameters.

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