Magnetic Resonance Imaging Screening for Trilateral Retinoblastoma: The Memorial Sloan Kettering Cancer Center Experience 2006–2016

Abstract

Magnetic resonance imaging (MRI) has been used for baseline brain imaging and afterward as a screening tool for trilateral retinoblastoma (TRB), but there is no consensus on timing or frequency of screening worldwide. In this study, a cohort of hereditary retinoblastoma patients at increased risk for TRB was identified and the usefulness of aggressive neuroimaging was examined. Retrospective review of the medical records and MRI reports of patients with retinoblastoma treated at Memorial Sloan Kettering Cancer Center between January 1, 2006, and December 31, 2016. Three hundred forty-nine total patients with retinoblastoma, including 215 hereditary retinoblastoma patients in the screening group. We reviewed 804 MRI studies of the orbit or brain. Patient and disease characteristics, including laterality, family history, and gene mutation status were analyzed. The impression of every MRI was coded 1 to 5, each value representing a different abnormality. We calculated the incidence of TRB in patients with germline disease as well as the incidence of screening MRI scans showing TRB. Among our hereditary retinoblastoma screening cohort (n=215) 4 patients with TRB were identified on screening MRI. All 4 patients showed bilateral disease, pineal gland tumors, and a latency period of at least 1 year. Three of the 4 were deceased by the end of the study. The incidence of TRB diagnosis was 1.9% (95% confidence interval [CI], 0.7%-4.9%). Of the 804 screening MRI scans performed on the screening cohort, 691 (86%) were unremarkable and 4 reported a lesion suspicious for TRB. The overall incidence of detecting TRB on screening MRI in the at-risk cohort was 0.5% (95% CI, 0.2%-1.3%) with a number needed to treat of 202. All cases of TRB in our center during the study period developed before the patient was 3 years of age and after a total of only 4 lifetime MRIs. Overall survival from TRB was not improved as a result of screening, andmany false-positive results required additional, subsequent MRI scans with anesthesia.