ROLE OF MULTISLICE CT IN STAGING OF NEUROBLASTOMA

Abstract

Neuroblastoma is the commonest extracranial pediatric solid tumor. It has an extremely heterogeneous behaviour, usually predictable from clinical and biologic features. Imaging by CT is important for diagnosis, staging and follow up of NB. Most treatment protocols include regular CT assessment to determine efficacy of therapy, thus helping to predict patients' prognosis. For a long time, the INSS has been routinely used for NB staging. However, some limitations were found as it is a post surgical system, depending on the surgeon's skill and can't be applied uniformly in different centers. The INRGSS is a recent pre treatment staging system for NB, based on imaging results taken before surgery. In this system, imaging by CT plays a central role in diagnosis and staging of NB. Absence or presence of 1 or more IDRFs, LN status and metastatic spread are used for accurate tumor staging. It broadly classifies NB into localized (L1 and L2 stages) and metastatic cases (M and MS stages). In this work, 20 NB cases were studied by CT scan. Similar to other studies, the most common clinical finding was an abdominal mass (85%) and the suprarenal gland was the most common site of primary tumor origin (50%). According to Shimada classification for tumor grading, 85% of cases were poorly differentiated. Positive LNs were found in 70%, and metastatic spread in 35% of patients respectively. IDRFs were similar but with a higher frequency than those of previous studies. All cases were staged by CT according to the INRGSS. Stage L2 was the most common stage (45%), followed by stage M (35%). L1 and MS stages were found in 15% in 5% of cases respectively. Staging according to the INSS was