Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer Using Optical Surface Management System – AlignRT as an Optical Body Surface Motion Management in Deep Breath Hold Patients: Results from a Single-Arm Retrospective Study

PURPOSE: To assess the efficacy and safety of stereotactic body radiotherapy for patients with unresectable, locally advanced pancreatic cancer using Optical Surface Management System – AlignRT (OSMS-AlignRT) as an optical body surface motion management in deep breath hold. PATIENTS AND METHODS: Forty-five patients diagnosed with locally advanced pancreatic cancer were treated with stereotactic body radiotherapy in 3 or 5 fractions, and received varying BED(10) (median 79.5 Gy) from April 2017 to December 2020. All patients were treated in deep breath hold with OSMS-AlignRT used as optical body surface motion management. Thirty-three patients received systemic treatment before and/or after stereotactic body radiotherapy, and twelve patients received no systemic treatment. In this retrospective, observational, single-arm study, primary endpoints were overall survival and freedom from local progression (ie, local control). Secondary endpoints were progression-free survival and toxicity. Actuarial survival analysis and univariate analysis were investigated. RESULTS: Data from forty-five patients were analyzed. Median follow-up was 15 months. One-year freedom from local progression and survival were 95.5% and 71.1%, respectively. Median progression-free survival was 14 months. Median overall survival from diagnosis for all patients was 17 months, and 19 months for patients alive at the time of analysis. No patient had >G2 toxicity. CONCLUSION: Stereotactic body radiotherapy for locally advanced pancreatic cancer using OSMS-AlignRT as optical body surface motion management in deep breath hold patients is an effective and safe local treatment option, with no >G2 toxicity, and could be a promising therapeutic option with acceptable toxicity, either as a single treatment or in a multimodal regimen. OSMS-AlignRT provided accurate and reliable body surface motion management during stereotactic body radiotherapy.