Assessing ‘second-look’ tumour resectability in childhood posterior fossa ependymoma—a centralised review panel and staging tool for future studies

Abstract

Purpose

To improve uniformity in radiological review/reporting and discussion of surgical resection status in the forthcoming SIOP Ependymoma II trial, a central review of imaging and resection status will be carried out prior to treatment stratification. We present a review of surgical decision-making from the UKCCSG/SIOP Ependymoma trial for very young children (<3 years) (Lancet Oncol 8:696–705, 2007) and propose a primary surgical staging system for residual disease that could be used for Ependymoma II.

Methods

Imaging of 89 patients enrolled in the UKCCSG infant Ependymoma trial was independently reviewed by 3 experienced paediatric neuro-oncology surgeons. Pre- and post-op MRI imaging was available for 28 posterior fossa cases with incomplete resection. Location of residual disease, decision to offer ‘second-look’ surgery (prior to adjuvant therapy), perceived chance of complete resection, and risk to cranial nerves was assessed. Recommendation for second-look surgery was compared with actual second-look surgery.

Results

In the actual study period, 13 patients (46 %) had further surgery at some point. The independent panel, after blinded review of the imaging, would have offered 19 patients overall (68 %) in this same cohort up-front early second-look surgery prior to definitive adjuvant therapy. We devised a 5-point staging system to introduce consistency in staging residual disease and resectability, and this is presented.

Conclusions

Based on scans alone, a surgical panel would have offered second-look surgery to 68 % of patients with residual ependymoma. The potential benefits and drawbacks of a surgical review panel and classification system will be discussed in the context of the forthcoming Ependymoma II trial.