Visual Outcome Following Fractionated Stereotactic Radiotherapy of Anterior Visual Pathway Meningiomas: Conventional vs. Hypofractionated

Anterior visual pathway meningiomas (AVPM) may affect visual functions (VFNS): visual acuity (VA) and visual field (VF). Due to location, most are treated non-surgically by fractionated stereotactic radiotherapy (FSRT), 28-30 fractions. Advances in technology and the will to shorten total treatment length have led to hypofractionation (HSRT), 3-5 fractions. Our purpose was to evaluate the association of radiotherapy regimen (FSRT vs HSRT) in AVPM and VFNS (VA, VF) outcomes.

Poster 86 Visual Outcome following Fractionated Stereotactic Radiotherapy of Anterior visual pathway Meningiomas: Conventional vs. Hypofractionated Ruth Huna-Baron1, Amir Agami2, Roberto Spiegelmann3, Ouzi Nissim3, Leor Zach4 Sackler School of Medicine Tel Aviv University & Sheba Medical Center, Ramat-Gan, Israel, 2Sackler School of Medicine Tel Aviv University, Tel Aviv, Israel, 3Radiosurgery unit ,Sheba Medical Center, Ramat-Gan, Israel, 4Neuro-Oncology Unit Sheba Medical Center and Tel Aviv University, Ramat-Gan, Israel 1 Introduction: Anterior visual pathway meningiomas (AVPM) may affect visual functions (VFNS): visual acuity (VA) and visual field (VF). Due to location, most are treated non-surgically by fractionated stereotactic radiotherapy (FSRT), 28-30 fractions. Advances in technology and the will to shorten total treatment length have led to hypofractionation (HSRT), 3-5 fractions. Our purpose was to evaluate the association of radiotherapy regimen (FSRT vs HSRT) in AVPM and VFNS (VA, VF) outcomes. Methods: We compared retrospectively FSRT and HSRT regarding final VA and VF results and change from pretreatment. VA and VF were determined by LogMAR and mean deviation (MD), respectively. We included patients with VFNS data for at least 18 months. Results: 48 patients (13 HSRT, 35 FSRT), were included. Median follow-up: 55 months (36-102). No statistical significant difference between the two groups was evident regarding final LogMAR (p=0.327) or final MD (p=0.935). Median change in LogMAR of involved eyes was 0.05 in HSRT, compared with 0.00 in FSRT (p=0.092). Clinically significant deterioration in visual acuity (ΔLogMAR≥0.2) in the involved eye: 6 patients (17%) in the FSRT cohort, and 6 patients (46%) in the HSRT cohort (p = 0.061). The median MD change, -1.6 in the FSR cohort versus -4.7 in the HSRT cohort (p = 0.043).Radiation retinopathy complicated 4 patients (13%) in the FSR cohort versus 1 patient (9%) in the HSRT cohort (p> 0.999). Conclusions: Our findings suggest that FSRT may be associated with less VA and VF deterioration. Given the small sample and retrospective nature of our study, caution is needed in drawing conclusions. Information from prospective studies involving more patients may improve our understanding of the relationship between radiation regimen and long-term outcomes in AVPM. Nevertheless, we believe our results may still indicate caution with the adoption of new radiation regimens without thorough investigation of VFNS outcome. References: None. Keywords: tumors, chemotherapy and radiation injury Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: None provided. 244 | North American Neuro-Ophthalmology Society