# Single-Fraction SBRT for Locally Advanced Pancreatic Cancer Using Total Intravenous Anaesthesia and Optical Surface Guidance: Technique and Preliminary Results

## TL;DR

This study shows that a new SBRT technique using anesthesia and motion tracking can safely and effectively treat advanced pancreatic cancer with high tumor control and survival rates.

## Contribution

First reported use of total intravenous anesthesia and optical surface guidance for single-fraction SBRT in locally advanced pancreatic cancer.

## Key findings

- One-year local tumor control was 100% with no grade > 2 toxicities.
- Median overall survival was 18 months with 90.9% one-year OS.
- Treatment was well-tolerated with no acute or late toxicity above grade 2.

## Abstract

Unresectable, locally advanced pancreatic cancer represents a particular problem for SBRT due to the tumour and surrounding healthy tissue, respiratory, and other movements, limiting the tumour dose. The aim of this study was to investigate the efficacy and safety of single-fraction SBRT for LAPC with dose escalation using total intravenous anaesthesia and optical surface guidance as motion management. With this technique, we aimed to almost completely mitigate the movements of the tumour and OARs, imitating the non-moving target SBRT, and this is the first reported application of this approach for LAPC. Using very narrow safety margins around the lesion during the treatment, we were able to effectively spare surrounding healthy organs and safely apply a median biological effective dose ≥ 128.9 Gy. Especially when combined with systemic therapy, the treatment resulted in very favourable one-year local tumour control of 100% and a median overall survival of 18 months, with no grade > 2 toxicities.

Background: The aim of this retrospective, single-arm study was to present the technique and preliminary efficacy and safety results of a single-fraction SBRT for LAPC using total intravenous anaesthesia and optical surface guidance as motion management. Methods: Fifty-five patients with locally advanced pancreatic cancer were treated with SBRT with a single-fraction receiving a median BED10 = 128.9 Gy. Forty-two patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Actuarial survival analysis and univariate analysis were investigated. Results: The median follow-up was 15 months, mean OS was 18 months (95% CI: 16.7 to 19.3), and the one-year FFLP and 1-year OS were 100% and 90.9% (95% CI: ± 1.5%), respectively. Median PFS was 12 months (95% CI: 9.5 to 14.4), and 1-year PFS was 85.5% (95% CI: ± 1.4%). Thirty-five patients (63.6%) were alive at the time of analysis. No acute/late toxicity > G2/G1 was reported. Conclusions: SBRT for LAPC using total intravenous anaesthesia and optical surface guidance presented as an effective and safe treatment with very low toxicity.