Magnetic Resonance Imaging Screening for Trilateral Retinoblastoma: The Memorial Sloan Kettering Cancer Center Experience 2006-2016.
PURPOSE: 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. DESIGN: 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. PARTICIPANTS: Three hundred forty-nine total patients with retinoblastoma, including 215 hereditary retinoblastoma patients in the screening group. METHODS: 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. MAIN OUTCOME MEASURES: We calculated the incidence of TRB in patients with germline disease as well as the incidence of screening MRI scans showing TRB. RESULTS: 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. CONCLUSIONS: 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, and many false-positive results required additional, subsequent MRI scans with anesthesia.