Validity of image-defined risk factors in localized neuroblastoma: A report from two centers in Western Japan

Abstract

Background: Japanese Neuroblastoma Study Group (JNBSG) has been employing image-defined risk factors (IDRFs) since 2010. However, the report from INRG in 2011 supplemented description stating that isolated contact is considered to be IDRF-positive only in renal vessels. The aim of this study was to evaluate the validity of IDRFs by comparing the previous (PG) and new guidelines (NG).

Methods: IDRFs of patients with localized neuroblastoma treated at two centers in Western Japan from 2002 to 2013 were retrospectively reviewed by radiologists.

Results: 47 neuroblastomas (abdomen 38, pelvis 2, mediastinum 7) were evaluated. For abdominal neuroblastomas, IDRFs were present in 15/38 (39.5%) using PG and in 31/38 (81.6%) using NG. Moreover, the IDRF-positive rate increased from 26.7% (4/15) to 80.0% (12/15) in 15 cases diagnosed during mass screening. Of the IDRF-positive cases, complete primary resection was achieved in 2/15 (13.3%) using PG and 17/31 patients (54.8%) using NG. There were two major surgical renal complications in the IDRF-positive cases based on the use of either guidelines, and the specificity decreased from 64% to 19%.

Conclusions: According to NG, the IDRF-positive rate increased, and the resection rate decreased. NG may overestimate surgical risks, leading to unnecessary chemotherapy and a prolonged hospital stay.

Keywords: IDRFs; INRG; JNBSG; Neuroblastoma; renal complication; surgery.