## 4 Discussion
### Treatment Technique  
The main objective of this work was to fully understand the grade of influence of the advanced parameters on the derived dose distribution and the development of treatment techniques for the investigated sites by fully understanding the impact of the adjustable parameters of the Pinnacle personalized planning engine. Many authors [6; 20; 22; 28; 43] reported the usefulness of the development of treatment techniques in terms of both an increase in plan quality and standardization among different planners and saving time for the planning operations for several treatment sites. However, no work has been conducted in depth to evaluate the possible impact on dose distribution of each customizable parameter, which must be specified when a technique is created. Thus, a total of 45 plans were generated by changing one parameter at a time in order to highlight its influence on the final calculated dose distribution. Thus, considering all the obtained results, two sets of advanced parameters have been proposed for the two different treatment sites and are currently under evaluation in the clinical settings. About this, some considerations must be examined. The plans obtained with \"initialize with conformal opening\" equal to \"yes\" and with \"match target coverage\" equal to \"no\" were considered not consistent with the minimal requirements needed for the development of a radiotherapy plan. These parameter values should be avoided unless they are very specific cases. The SRS/SBRT normal tissue control mode has also been investigated for SBRT plans. Even if this selectable option has been designed to achieve better dose conformity to the target when set to SRS/SBRT, it is much more effective in the case of small PTV volumes suitable for stereotactic irradiation, as well described in [PERSON] et al. [22]. Thus, evaluations of the advanced parameter values necessary to achieve a suitable template for stereotactic body radiotherapy are now of major interest, and specific work is currently under preparation. Finally, the CLM has proven to be the most pivotal parameter in plan delivery accuracy, and, therefore, it must be carefully chosen, as already reported by [PERSON] et al. [44]. For this reason, our study conducted a comprehensive assessment of the plan quality in terms of dosimetric indexes and delivery accuracy by varying the CLM value. In all the investigated values except for CLM = 0.46 cm/deg, the plans were clinically acceptable, with satisfactory PTV coverage and OAR sparing. However, decreasing values of the \(\gamma\)-passing rate were observed for CLM > 0.8 cm/deg with an absolute minimum when no value was set. Regarding the clinical significance of the observed variations in dose distributions in OAR doses, deliverable and undeliverable plans were not significantly statistically indistinguishable. In addition, the target and OAR goals were those suggested by AAPM Task Group 244. QUANTEC (Quantitative Analyses of Normal Tissue Effects in the Clinic) guidelines provide valuable insights into dose-volume relationships and their correlation with toxicity for various organs [45]. These guidelines emphasize that the risk of toxicity is often probabilistic and influenced by factors such as total dose, fractionation, and organ-specific volume effects. Generally, treatment plans are accepted by radiation oncologists during the plan discussion and acceptance phase, when the dose received by an organ volume remains below established constraints, implying a binary interpretation of organ response--either 0 (no toxicity) or 1 (toxicity). However, the clinical significance and impact of adhering to these constraints should be evaluated biologically, considering the entire DVH. It is essential to consider whether the dose-response curve for a specific organ demonstrates a sharp, step-like transition from 0 to 1 over a few Gy (indicating a steep dose-response relationship) or follows a more gradual, smoothed progression.