Clinical Significance of FDG PET/CT in the Pediatric Neuroblastoma

Objectives FDG PET imaging is well known to have clinical significance in the initial staging and response evaluation in the many kinds of neoplasms. However, its role in the pediatric neuroblastoma is not clearly defined. In the present study, clinical significance of FDG PET/CT in the pediatric neuroblastoma was investigated.

Methods Fifty-eight patients who pathologically diagnosed as neuroblastoma and underwent FDG PET/CT at Seoul National University Hospital from 2008 to 2015 were retrospectively enrolled in the present study. Clinical information including histopathology, serum markers, and several PET parameters including SUVmax of primary lesion (Pmax), SUVmax of metastasis (Mmax), and target-to-background ratio (TBR) were analyzed. Subgroup analysis was performed based on patients with diagnostic work-up FDG PET/CT before any treatment. Prognostic effect of PET parameters was evaluated in terms of progression-free survival (PFS).

Results Among 58 patients (3.1 ± 2.9 years), stage I was 8.6 %, stage II 5.2 %, stage III 16 %, and stage IV 71%, respectively. Primary lesion was located in adrenal gland 50%, retroperitoneum 34%, posterior mediastinum 16%, and histopathology was ganglioneuroblastoma 22%, well-differentiated neuroblastoma 17%, poorly-differentiated 47%, and unknown state 14%. Fifty-three percent patients showed bone marrow involvement in the initial diagnostic state. Age, stage, MYCN status, primary tumor size, serum LDH/ferritin, and FDG PET parameters such as Pmax, Mmax, and TBR were significantly related with progression on t-test or chi-square test (age, p = 0.02 ; stage, p = 0.008 ; MYCN, p = 0.013 ; tumor size, 0.045 ; LDH, p = 0.037 ; ferritin, p = 0.019 ; Pmax, p = 0.039 ; Mmax, p = 0.011 ; TBR, p = 0.023). In 20 patients group with diagnostic work-up FDG PET before any treatment, PFS was significantly associated with Pmax (p = 0.021) and Mmax (p < 0.001).

Conclusions FDG PET parameters including SUVmax and TBR were significantly related with progression of neuroblastoma. In addition, Pmax and Mmax on diagnostic work-up FDG PET was a significant prognostic factor. FDG PET/CT has the potential as a valuable modality for evaluating prognosis in the patients with pediatric neuroblastoma.