Updated Recommendations for Retinoblastoma Imaging: Insights from the European Retinoblastoma Imaging Collaboration and the European Retinoblastoma Group, 2025 Edition

Category	Detail
Condition	Retinoblastoma, the most common intraocular malignancy in children
Key Mechanisms	Tumor detection via fundoscopy and ultrasonography; MRI for tumor extension and staging
Target Population	Children suspected or diagnosed with retinoblastoma
Care Setting	Ophthalmology and radiology departments with access to MRI and ultrasonography

Ultrasonography is first-line for detecting intratumoral calcifications, especially when fundoscopy is limited.
High-resolution contrast-enhanced MRI is essential for pretreatment staging, assessing intra- and extraocular spread, and intracranial involvement.
CT is no longer recommended due to low sensitivity, specificity, and radiation risks in children.

Use fundoscopy and ultrasonography under general anesthesia for initial diagnosis.
Confirm intratumoral calcifications with ultrasonography when fundoscopy is limited.
Avoid CT scans due to radiation exposure and inferior diagnostic accuracy.

Employ high-resolution contrast-enhanced MRI for detailed tumor staging and assessment of optic nerve invasion and trilateral retinoblastoma.
Use 3-T MRI systems with multi-channel head coils or 1.5-T systems with surface coils covering both eyes.
General anesthesia is recommended to minimize eye movement and optimize image quality.

Perform MRI with high spatial resolution (in-plane pixel size ≤ 0.3 × 0.3 mm, slice thickness ≤ 2 mm) for orbit imaging.
Include axial isotropic 3D heavily T2-weighted sequences and pre- and post-contrast 2D axial T1-weighted spin echo images aligned with the optic nerve axis.
Repeat MRI under appropriate conditions if initial imaging quality is suboptimal, especially when anesthesia is not feasible.

Radiation exposure from CT scans poses significant risk, especially in children with tumor-predisposing genetic conditions.
Suboptimal MRI quality without general anesthesia may impair detection of optic nerve invasion.

Pediatric patients with suspected or confirmed retinoblastoma

Imaging guides staging and management decisions; MRI is preferred modality to minimize radiation and maximize diagnostic accuracy.

Perform fundoscopy and ultrasonography under general anesthesia for initial evaluation.
Use high-frequency (up to 22 MHz) linear probes for ultrasonography to detect microcalcifications.
Prefer MRI over CT for locoregional and intracranial assessment.
Ensure MRI protocols include high-resolution orbit imaging and brain coverage including pineal region.
Align MRI slices precisely along the optic nerve axis for accurate assessment of invasion.
Avoid CT scans to reduce radiation exposure in children.
If general anesthesia is not feasible, consider but do not prefer the 'feed-and-swaddle' technique; repeat MRI under anesthesia if needed.

Clinical Scorecard: Updated Recommendations for Retinoblastoma Imaging: Insights from the European Retinoblastoma Imaging Collaboration and the European Retinoblastoma Group, 2025 Edition