Rana Suresh, Padannayil Noufal Manthala, Zeidan Youssef, Pokharel Shyam, Richter Samuel, Kasper Michael, Saeed Hina
Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL, USA.
Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL, USA.
Phys Med. 2024 Dec;128:104863. doi: 10.1016/j.ejmp.2024.104863. Epub 2024 Nov 30.
This study aims to compare the dosimetric impact of incorporating systematic and random setup uncertainties in the robust optimization of head and neck cancer (HNC) Intensity Modulated Proton Therapy (IMPT) plans.
Bilateral HNC patients (n = 10) previously treated with conventional photon therapy at our institution were included. Both systematic and random setup uncertainties were incorporated into the robust optimization process of IMPT planning. Dosimetric comparisons were made between plans optimized with systematic (IMPT-S) versus random (IMPT-R) setup uncertainties, assessing both the clinical target volume (CTVs) and organs at risk (OARs) across various dosimetric metrics. Both plans applied a fixed range uncertainty of ± 3 % and a maximum setup uncertainty of ± 3 mm.
Both IMPT-S and IMPT-R plans achieved similar target coverage, meeting robustness criteria for CTVs. On average, the D voxel-wise min to the high-risk CTV (CTV_HR) was slightly higher in IMPT-S plans by 1.78 ± 0.72 % compared to IMPT-R plans. However, IMPT-R plans provided better OAR sparing, which was evident in both nominal and voxel-wise maximum values. While random setup errors in robust optimization improved OAR sparing, the clinical impact may be minimal where OAR doses are already well below tolerance levels.
Both IMPT-S and IMPT-R techniques met the robustness criteria for CTVs in HNC IMPT planning. Incorporating random setup uncertainties in robust optimization improves OAR sparing compared to systematic setup uncertainties. Further research is needed to explore the broader applicability of random setup errors and to integrate random uncertainties in robustness evaluations for a more comprehensive assessment of treatment plans.
本研究旨在比较在头颈部癌（HNC）调强质子治疗（IMPT）计划的稳健优化中纳入系统和随机摆位不确定性的剂量学影响。
纳入了10例先前在本机构接受过传统光子治疗的双侧HNC患者。将系统和随机摆位不确定性都纳入IMPT计划的稳健优化过程中。对采用系统摆位不确定性（IMPT-S）与随机摆位不确定性（IMPT-R）优化的计划进行剂量学比较，评估不同剂量学指标下的临床靶区（CTV）和危及器官（OAR）。两种计划均采用±3%的固定射程不确定性和±3 mm的最大摆位不确定性。
IMPT-S和IMPT-R计划均实现了相似的靶区覆盖，满足CTV的稳健性标准。平均而言，与IMPT-R计划相比，IMPT-S计划中高危CTV（CTV_HR）的体素最小剂量（D voxel-wise min）略高1.78±0.72%。然而，IMPT-R计划对OAR的保护更好，这在标称值和体素最大值中都很明显。虽然稳健优化中的随机摆位误差改善了对OAR的保护，但在OAR剂量已经远低于耐受水平的情况下，临床影响可能很小。
IMPT-S和IMPT-R技术在HNC的IMPT计划中均满足CTV的稳健性标准。与系统摆位不确定性相比，在稳健优化中纳入随机摆位不确定性可改善对OAR的保护。需要进一步研究以探索随机摆位误差的更广泛适用性，并将随机不确定性纳入稳健性评估中，以更全面地评估治疗计划。
