# Propofol Total Intravenous Anesthesia for Pediatric Proton Radiotherapy and Its Effect on Patient Outcomes

## TL;DR

This study found that using propofol anesthesia for children's proton radiotherapy does not affect survival but increases the risk of unplanned hospital visits.

## Contribution

The study is the first to investigate the impact of repeated propofol anesthesia on survival and hospital visits in pediatric proton radiotherapy patients.

## Key findings

- Propofol-based anesthesia did not affect overall survival rates in children undergoing proton beam therapy.
- Children receiving propofol anesthesia were 38 times more likely to have unplanned hospital admissions or emergency room visits.
- Patients with propofol anesthesia were younger and had more treatment interruptions and chemotherapy history.

## Abstract

To facilitate the safe and accurate delivery of radiotherapy, children undergoing proton beam therapy may require multiple anesthetic exposures over a period of 6 to 8 weeks. Research suggests the choice of anesthetic agent may influence cancer progression. To date, the influence of this many anesthetic exposures on the short- and long-term outcomes of children undergoing radiotherapy is unknown. In this retrospective study, multiple anesthetic exposures with propofol-based total intravenous anesthesia did not influence the survival of children undergoing proton beam therapy. However, compared to children who completed proton beam therapy without anesthesia, those who were undergoing treatment with propofol-based anesthesia were 38 times more likely to require an unplanned admission or emergency room visit. Further studies involving the use of other anesthetic agents may guide practitioners in selecting the preferred agents for this group of patients.

Background: Patient motion poses significant challenges for the accurate delivery of radiotherapy. In children undergoing proton beam therapy (PBT), up to 30 treatments under general anesthesia may be required over a period of 6 to 8 weeks. To date, the impact of this many iterative anesthetic exposures on patient outcomes remains unclear. Objective: The primary objective of this study was to assess the impact of iterative anesthesia with propofol-based total intravenous anesthesia (propofol-TIVA) on overall survival. The secondary objective was to assess the association between propofol-TIVA and the occurrence of an unplanned admission or emergency room visit within 30 days of treatment start. Methods: This was a retrospective study of children (≤19 years) who had undergone PBT (with or without anesthesia) for central nervous system disease. The Log-rank test and Cox proportional hazards models were used for analysis. Propensity score matching and E-value analyses were used to adjust for selection bias. Results: The average age of the 461 children included was 9.0 years (SD ± 4.9). The majority, 261/461 (56.6%), were male, and 267/461 (57.9%) had undergone PBT without anesthesia. The group who underwent PBT with propofol-TIVA were younger (4.7 years vs. 12.2 years, p < 0.001) and had higher proportions of patients with treatment interruptions (111/194 [57.2%] vs. 118/267 [44.2%], p = 0.006), chemotherapy history (64/194 [33.0%] vs. 18/267 [6.7%], p < 0.001), concurrent chemotherapy (37/194 [19.1%] vs. 27/267 [10.1%], p = 0.006), and unplanned admissions/emergency room visits (26/194 [13.4%] vs. 1/267 [0.4%], p < 0.001). Overall survival rates (propofol-TIVA vs. no anesthesia) at 1yr (94% vs. 96%), 2 years (88% vs. 90%), and 3 years (88% vs. 89%) were similar between patient groups (p = 0.558). In the multivariable analysis, PBT with propofol-TIVA was associated with increased odds of an unplanned admission/emergency room visit before (OR, 38.311; 95%CI, 5.139–285.580; p < 0.001) and after (OR, 42.012; 95% CI, 5.322–331.632; p < 0.001; E-value = 83.52) propensity score matching. Conclusions: In this retrospective study of children undergoing PBT for central nervous system disease, there was no association between anesthesia exposure with propofol-based total intravenous anesthesia and overall survival. However, PBT with propofol-based total intravenous anesthesia was associated with an increased risk of an unplanned admission/emergency room visit within 30 days of treatment start.