Role of FDG PET/CT in Diagnosing and Assessment of Therapy Response in Pediatric and Adult patients with Renal Lymphoma

Introduction: Extra-nodal spread of lymphoma is not commonly affect the genitourinary system & primary renal lymphoma is very rare. The aim of current study is to evaluate the role of FDG PET/CT in assessment of the differences in distribution, pattern, therapy response and outcomes of renal lymphoma between the pediatric and adult age groups.Materials & Methods: 62 patients (32 Adult and 30 Pediatric) with pathologically proven lymphoma with renal involvement. FDG PET/CT scan were assessed retrospectively with analysis of their clinical/radiological data, therapy response, prognosis and survivals.Results: Incidence of primary renal lymphoma in adult and pediatric age groups represent 15.6% and 3.3 % respectively. Focal pattern was the most common on both groups ( 93.8% and 76.7% respectively). Bilateral renal involvement and the diffuse pattern of infiltration were more prevalent (78.6% & 23.6% respectively) among the pediatric group compared to (41.9% & 6.3%) in adult patients. Pediatric group show better OS and EFS as well as good prognosis. Statistical significance was found between the two groups regarding the SUVmax of the renal lesion, Nodal SUVmax, EFS and OS, with P value 0.004, 0.024, 0.019 & 0.004 respectively.Conclusions: Primary renal lymphoma incidence is less than the secondary type and more relevant in adult group. Pediatric group shows better OS and EFS as well as good prognosis.