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

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.