Background: Nasopharyngeal carcinoma (NPC) is one of the few epithelial-origin tumors observed in pediatric population accounting for around 1–5% of all pediatric cancers and characterized with higher incidence of advanced loco-regional compromise. Aim of the work: to explore the impact of 18F-FDG-PET/CT in pediatric nasopharyngeal carcinoma (PNPC) either during initial staging or re-staging after end of therapy versus conventional imaging (CI) modalities (MRI and Ce-CT). Patients and methods: 40 patients with biopsy proven PNPC (mean age 13, SD ± 2.3; range 9-17) mostly of non-keratinizing undifferentiated type III (95%) were included in the study. Whole body 18F-FDG-PET/CT, MRI and CE-CT of the head and neck were obtained in all patients, as well as MRI and CE-CTof the chest and the abdomen (the interval between the different modalities ranged from 2-28 days). The findings of PET/CT were compared with those of CI modalities regarding the TNM staging either initially or after end of therapy. Results: the studied group of patients was divided into two categories for analysis; 21 patients were analyzed at initial staging (52.5%) and 19 patients (47.5%) were analyzed for restaging after end of 1st line of therapy. In initial staging; The T stage detectability revealed a higher sensitivity for MRI versus PET/CT with sensitivity of 100% vs. 95.2% for PET/CT and MRI respectively. Regarding the N stage; PET/CT shows higher sensitivity than CI modalities with sensitivity values of 95.2% and 88.8% and 77.7% for PET/CT, MRI, and CT respectively.In respect of the M stage; the sensitivity values were 80%, 60% and 25% for PET/CT, MRI, and CT respectively. In re-staging; PET/CT has higher sensitivity than CI modalities for local residual/recurrence (T), nodal (N) and distant metastases (M) with values of 100% vs. 86% in T stage, 100% vs. 91% in N stage and 100% vs. 66% in M stage for PET/CT and CI modalities respectively.
Conclusion: 18F-FDG-PET/CT is considered a potentially valuable imaging tool in PNPC either in initial staging or restaging which could effectively change the overall staging and hence the management.