Role of Positron Emission Tomography/ Computed Tomography (PET/CT) in assessment of pediatric lymphoma

Abstract

Lymphoma accounts for approximately 10% of childhood cancers, but 17% in teenagers. It is divided into Hodgkin and non-Hodgkin lymphoma, with the vast majority of non-Hodgkin lymphoma in children being Burkitt lymphoma, lymphoblastic lymphoma and anaplastic large cell lymphoma (Jacob and Evans, 2011). Lymphoma usually presents with painless lymphadenopathy, most commonly in the cervical region. ‘B’ symptoms are associated with more advanced disease. The diagnosis is usually made by histological examination of an excised lymph node, but can be made on pleural fluid or a bone marrow aspirate (Jacob and Evans, 2011). Diagnostic CT is often the first study in pediatric patients who are suspicious for lymphoma, but FDG-PET/CT offers more accurate staging and leads to upstaging, and sometimes down staging, in many patients, because of the capability of PET to detect additional nodal lesions, and more importantly, in the detection of BM involvement and other extra nodal lesions (Cheng et al., 2012). FDG-PET/CT is more accurate than BMB in the evaluation of BM involvement and provides guidance in the selection of a biopsy site. FDG- PET/ CT has essentially replaced bone scan for assessment of BM infiltration, and replaced the 67Ga scan for assessment of lymphoma activity (Cheng et al., 2012).