PET/CT in Acute Leukemia

CT) is a noninvasive radionuclide-based whole body imaging technique which combines both a Positron Emission Tomography (PET) scanner and an x-ray Computed Tomography (CT) scanner in a single gantry system. In PET, functional images are obtained which denotes spatial distribution of metabolic or biochemical activity in the body. These images are aligned with anatomical images obtained by CT scanner in the same session resulting in a single superposed (co-registered) image [1]. Functional changes in bone/ bone marrow may precede structural changes which can be efficiently picked by PET/CT scan. Normal red marrow usually demonstrates low intensity 18FFDG uptake, thereby helping in detection of increased uptake in early marrow involvement. FDG-PET/CT is not regularly used in the assessment of acute or chronic leukemia’s [2]. But, few case reports were described in the literature which demonstrated the potential role of FDGPET/CT in diagnosis and follow-up of leukemic bone marrow infiltration [3,4]. In addition to this whole-body FDG-PET is valuable for the detection of extra-medullary leukemia/myeloid sarcoma with systemic overview of tumor burden at diagnosis and relapses and can also be used for monitoring of treatment response [5,6]. FDG-PET/ CT is also useful in diagnosis and prognostic stratification as well as detection of Richter’s transformation in CLL cases [7-10]. FDG PET has also role in diagnosis and monitoring of Chronic Myeloid Leukemia (CML) after treatment [11,12].