## 3 Results  
Figure 1 shows an example of a head and neck case replanned using the selected strategies. Figure 2 shows the \(DVC_{norm}\) for CTV/PTV, BODY, and OARs for the first three patients replanned using all eight different strategies (i.e., 32 plans for a total of 81 arcs). Similarly, Figure 3 shows the box plots of the MCS, pGPR, and mGPR. Overall, we observed an average increase in DVCnorm for OARs (+6.5%) and BODY (+1.5%), with a decrease for CTV/PTV (\(-1.3\%\)). The following optimization strategies were discarded according to these reasons:  
* NoChanges: it produced arcs with the highest complexity (MCS = 0.14) and worse pGPR = 92.5%. * ASC_VL: it produced high complexity arcs (MCS = 0.16) with the lowest pGPR = 92.5% and mGPR = 98.8% among the ASC settings. * ASC_VH: despite it yielding the highest pGPR = 95.5% and mGPR = 99.3%, it was the worst method with respect to the DVCnorm values, with \(-2.4\%\) for CTV/PTV, +7.0% for OARs, and +2.6% for BODY. * ASC_M: this strategy was comparable to ASC_H in terms of all the considered parameters. In order to explore polarized settings, we eventually opted to consider ASC_L and ASC_H for the subsequent analysis. Furthermore, we included the MUlimit as it produced arcs with minimal complexity (MCS = 0.21) and because of its widespread implementation across many commercial TPSs. Therefore, the remaining seven patients were re-optimized with these three strategies and the analysis repeated, totaling 128 arcs from 40 treatment plans. Figure 1: Example of selected replanning strategies for a head and neck case. The values for the MCS, pGPR, and mGPR represent the plan average. Abbreviations: ASC = aperture shape controller, DVC = dose volume constraint, MCS = modulation complexity score, mGPR = measured gamma passing rate, MU = monitor unit, pGPR = predicted gamma passing rate. Figure 2: DVCnorm for the clinical plans and the re-optimized plans with the eight replanning strategies used for the first three patients. ASC = aperture shape controller, DVC = dose volume constraint, MCS = modulation complexity score, mGPR = measured gamma passing rate, MRO = manual re-optimization, MU = monitor unit, pGPR = predicted gamma passing rate. Table 2 summarizes the change in the DVC and deliverability among the different replanning procedures. For all of them, we observed a median increase in DVCs for OARs and BODY, and a median reduction in the CTV/PTV. In particular, we found significant differences in the DVCnorm of CTV/PTV and OARs for the MUlimit and ASC_H strategies. Figure 4 shows the box plots of the DVCnorm for all of the considered structures. We highlight that the replanning processes did not compromise the overall dosimetric quality of the plans since the clinical constraints were still respected for all cases. \begin{table}
\begin{tabular}{c c c c c} \hline
**Parameter** & **Clinical** & **MUlimit** & **ASC\_L** & **ASC\_H** \\ \hline DVCnorm CTV/PTV (\%) & - & \(-1.5\)* [\(-2.4\), \(-1.2\)] & \(-0.6\) [\(-0.9\), \(-0.4\)] & \(-0.8\)* [\(-1.2\), \(-0.3\)] \\ DVCnorm OARs (\%) & - & \(1.9\)* [\(1.2\), \(4.6\)] & \(1.5\)[\(-0.4\), \(2.7\)] & \(2.3\)* [\(0.1\), \(4.7\)] \\ DVCnorm BODY (\%) & - & \(1.2\)[\(0.1\), \(2.8\)] & \(0.6\)[\(-0.1\), \(2.0\)] & \(0.9\)[\(0.7\), \(2.4\)] \\ MCS & \(0.17\)[\(0.13\), \(0.18\)] & \(0.21\)* [\(0.17\), \(0.24\)] & \(0.19\)* [\(0.14\), \(0.21\)] & \(0.20\)* [\(0.15\), \(0.24\)] \\ pGPR 3\%/1 mm (\%) & \(93.3\)[\(98.8\), \(94.9\)] & \(94.4\)[\(91.2\), \(96.5\)] & \(95.0\)* [\(92.4\), \(97.3\)] & \(95.1\)* [\(93.5\), \(96.1\)] \\ mGPR 3\%/1 mm (\%) & \(99.3\)[\(98.3\), \(99.8\)] & \(99.7\)[\(99.2\), \(99.9\)] & \(99.5\)* [\(99.2\), \(99.9\)] & \(99.8\)* [\(99.3\), \(99.9\)] \\ \hline \end{tabular}
\end{table} 
Table 2: Change in DVCs and deliverability for the different replanning strategies. Median values with the 1 st and 3 rd quartile are reported. Significant differences between replanned and clinical plans are marked with *.