Practical guidelines on imaging of retinoblastoma: a 2025 update on behalf of the European Retinoblastoma Imaging Collaboration and the European Retinoblastoma Group.

Retinoblastoma is the most common intraocular malignancy in children. Imaging plays a crucial role in evaluating children with retinoblastoma, both to determine tumor extension and to confirm the diagnosis when necessary. The eighth edition of the American Joint Committee on Cancer (TNM) classification provides a comprehensive intraocular and extraocular staging for retinoblastoma, with a key role for imaging, particularly in cases of advanced tumors. Imaging guidelines for retinoblastoma were first outlined by the European Retinoblastoma Imaging Collaboration (ERIC) in 2012. Over the past decade, technological advancements have enabled the acquisition of higher-resolution MR images and expanded our understanding of clinically significant imaging features of retinoblastoma. This manuscript aims to highlight these evolving insights in retinoblastoma imaging and to promote standardization of imaging practices. We propose an updated MR protocol and a standardized reporting system based on the key points essential for managing patients with retinoblastoma by ophthalmologists and pediatric oncologists. KEY POINTS: Question Advancements in imaging technology and updated TNM classification require revising retinoblastoma imaging guidelines to standardize practices and improve accuracy. Findings High-spatial-resolution contrast-enhanced MRI, performed within two weeks of diagnosis, under general anesthesia, is essential for pretreatment staging. The MRI protocol must include mandatory sequences for accuracy. Clinical relevance Retinoblastoma imaging is essential for diagnosis and tumor extension assessment. The updated guidelines, aligned with the eighth edition of the AJCC TNM classification, aim to standardize practices, improve imaging accuracy, and assist ophthalmologists and pediatric oncologists in patient management.