Stereotactic Ablative Radiotherapy Using CALYPSO® Extracranial Tracking for Intrafractional Tumor Motion Management—A New Potential Local Treatment for Unresectable Locally Advanced Pancreatic Cancer? Results from a Retrospective Study

Abstract

(1) Background: The aim of this study was to evaluate the efficacy and safety of SABR for LAPC using Calypso® Extracranial Tracking for intrafractional, fiducial‐based motion management, to present this motion management technique, as there are yet no published data on usage of Calypso® during SABR for LAPC, and to report on our clinical outcomes. (2) Methods: Fifty‐four patients were treated with SABR in one, three, or five fractions, receiving median BED10 = 112.5 Gy. Thirty‐eight patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Ac-tuarial survival analysis and univariate analysis were investigated. (3) Results: Median follow‐up was 20 months. Median OS was 24 months. One‐year FFLP and one‐year OS were 100% and 90.7%, respectively. Median PFS was 18 months, and one‐year PFS was 72.2%. Twenty‐five patients (46.3%) were alive at the time of analysis, and both median FU and OS for this subgroup were 26 months. No acute/late toxicity > G2 was reported. (4) Conclusions: SABR for LAPC using Calypso® presented as an effective and safe treatment and could be a promising local therapeutic option with very ac-ceptable toxicity, either as a single treatment or in a multimodality regimen. Dose escalation to the tumor combined with systemic treatment could yield better clinical outcomes.