MRI-guided Real-time Online Gated Stereotactic Body Radiation Therapy for liver tumours

Abstract Background Liver tumors are commonly encountered in Oncology. The study aimed to assess the impact of MRI-guided SBRT (MRgSBRT) on disease-related outcomes and the toxicity profile. Methodology Patients who received MRgSBRT from 2019 to 2021 for primary and metastatic liver tumors were included in this analysis. The protocol for treatment simulation included Gadoxetate disodium injection followed by a single-dimensional post-exhale MRI(0.35 T MRI linear accelerator) and CT simulation. The patient demographics and treatment-related outcomes were assessed. The time-to-event curves were analyzed for freedom from local progression (FFLP) and overall survival (OS). Results A total of 35 patients were eligible for analysis with a median age of 70 years (range 25–95). The median follow-up was 19.4 months (range 1–37 months). The one-year OS was 77.7%, with an estimated 3 years of 47.9%. Patients with locally controlled disease had better median overall survival of 27.8 months [95%CI (23.8–31.6)] compared to 13.5 months [95%CI (5.6–21.3), p = 0.007] in patients with local disease progression. The one-year FFLP was 95.6%, and three year estimated FFLP was 87.1%. Patients who received a radiation dose of BED ≥ 100Gy had FFLP of 30.9 months [95%CI (28.7–33.1)] compared to 13.3 months [95%CI (5.3–21.3), p value = 0.004] in patients who received < 100Gy BED. Conclusion MRI-guided SBRT provides optimal local control, associated with improved overall survival in a heavily morbid, pretreated older cohort of patients with reasonable safety profiles.