Imaging in Ocular Tumor Staging
Staging of retinoblastoma in the United States and other developed countries almost universally applies to intraocular retinoblastoma using the International Classification for Intraocular Retinoblastoma, a system that stratifies the chance of ocular sparing with current treatments. For extraocular retinoblastoma, several classification systems exist, including the International Retinoblastoma Staging System and the American Joint Committee on Cancer (AJCC) TNM Staging System, among others4. Choroidal invasion and early stages of optic nerve invasion remain challenging by imaging. As such, histopathologic evaluation remains the gold standard for such invasion assessment. Regardless, optimized, high resolution imaging of the orbit is critical in the preoperative assessment and characterization of tumor location and extent, including identifying extraocular invasion (e.g., optic nerve invasion) as it relates to these staging systems 5.