ESTRO 2024 - Abstract Book

S3429

Physics - Dose calculation algorithms

ESTRO 2024

Results:

In the phantom case, we found relevant qualitative differences between the dose distributions calculated by the two algorithms in correlation with the CTR value. We divided our sample in two groups, the first one with CTRs ranging from 0 and 0.33 and the second with CTRs above 0.33. As shown in Figure 2, the low CTR group presents higher differences than the mid-high CTR group for the D2% parameter. These differences are statistically significant (p = 0.026 for D2%) and are also correlated with CTR for D98% (p= 0.027). Regarding the clinical cases, the lesions of this group correspond to PTVs with equivalent sphere diameters ranging from 0.98 cm to 2.45 cm and CTRs between 0.00 and 0.90, both variables roughly normally distributed. We performed an equivalent analysis for both cases, which showed significantly less difference between the two groups. Neither the average reconstruction group nor the gated group showed any statistically significant differences.