Metric and statistical analysis

Dosimetric and volumetric data were tested for statistical significance using SPSS (IBM Corporation, Armonk, NY). Wilcoxon signed-rank tests tested for significant differences between GAS_P and mean GAS_C across the cohort. A Pearson correlation test was used to test for a relationship between GAS_P and differences in mean GAS_C. One-way analysis of variance tested for significant differences between the mean fractional dose metrics and the mean planned dose metrics of the Ref_0.0, Ref_0.5, and Ref_1.0 plans for all patients. A Pearson correlation test was used to test for a relationship between relative changes in mean GAS_C and changes in the accumulated dose metrics for target structures.

Patients’ BMI and weight were assessed using independent t tests and Pearson correlation tests to determine whether they had a relationship with the volume of GAS_P and GAS_C. For all statistical analyses, 2-sided tests were applied, and P values <.05 were considered statistically significant.