Asphericity of tumor [123 I]mIBG uptake as a prognostic factor in high-risk neuroblastoma.

BACKGROUND: In recent years, many research groups have attempted to identify a subgroup of "ultra-high risk" patients within the high-risk neuroblastoma (NB) category. The aim of our study was to evaluate the prognostic significance of parameters derived from pretherapeutic 123 I-meta-iodobenzylguanidine ([123 I]mIBG) integrated single photon emission computed tomography and computed tomography in high-risk patients with NB. METHODS: The established parameters metabolic tumor volume (MTV), maximal standardized uptake value (SUVmax ) and the novel parameter tumor asphericity as well as clinical (age, stage) and genetic factors (1p/11q deletions and MYCN amplification) were analyzed in this single-center retrospective study of high-risk patients with newly diagnosed NB. Univariate/multivariable Cox regression and propensity score matching were performed for clinical and radiological parameters. RESULTS: Twenty-eight high-risk patients with NB were included (14 males, median age 28.8 (11.3-41.0), range 3-74 months). Multivariable analysis of "full" cohort identified high asphericity (≥65%, adjusted hazard ratio [HR] 5.32, 95% confidence interval [CI]: 1.18-24.07, p = .03) and MTV (≥50 ml, adjusted HR 4.31, 95% CI: 1.18-15.80, p = .027) as the only factors associated with worse event-free survival. In matched cohort, tumor asphericity was a significant predictor of relapse/progression (HR 3.83, 95% CI: 1.03-14.26, p = .046). CONCLUSION: In this exploratory study, imaging parameters related to tumor metabolic activity, tumor asphericity and MTV, provided prognostic value for event-free survival in high-risk NB patients. Asphericity ≥65% and MTV ≥50 ml may serve as additional prognostic factors to those already used.