Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands.
Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands.
Radiother Oncol. 2023 Jul;184:109670. doi: 10.1016/j.radonc.2023.109670. Epub 2023 Apr 12.
In the model-based approach, patients qualify for proton therapy when the reduction in risk of toxicity (ΔNTCP) obtained with IMPT relative to VMAT is larger than predefined thresholds as defined by the Dutch National Indication Protocol (NIPP). Proton arc therapy (PAT) is an emerging technology which has the potential to further decrease NTCPs compared to IMPT. The aim of this study was to investigate the potential impact of PAT on the number of oropharyngeal cancer (OPC) patients that qualify for proton therapy.
A prospective cohort of 223 OPC patients subjected to the model-based selection procedure was investigated. 33 (15%) patients were considered unsuitable for proton treatment before plan comparison. When IMPT was compared to VMAT for the remaining 190 patients, 148 (66%) patients qualified for protons and 42 (19%) patients did not. For these 42 patients treated with VMAT, robust PAT plans were generated.
PAT plans provided better or similar target coverage compared to IMPT plans. In the PAT plans, integral dose was significantly reduced by 18% relative to IMPT plans and by 54% relative to VMAT plans. PAT decreased the mean dose to numerous organs-at-risk (OARs), further reducing NTCPs. The ΔNTCP for PAT relative to VMAT passed the NIPP thresholds for 32 out of the 42 patients treated with VMAT, resulting in 180 patients (81%) of the complete cohort qualifying for protons.
PAT outperforms IMPT and VMAT, leading to a further reduction of NTCP-values and higher ΔNTCP-values, significantly increasing the percentage of OPC patients selected for proton therapy.
在基于模型的方法中，当与 VMAT 相比，调强质子治疗（IMPT）所获得的毒性风险降低（ΔNTCP）大于荷兰国家适应证协议（NIPP）定义的预定阈值时，患者有资格接受质子治疗。质子弧治疗（PAT）是一种新兴技术，与 IMPT 相比，它有可能进一步降低 NTCP 值。本研究旨在探讨 PAT 对有资格接受质子治疗的口咽癌（OPC）患者数量的潜在影响。
研究了 223 例接受基于模型选择程序的 OPC 患者的前瞻性队列。在计划比较之前，有 33 例（15%）患者被认为不适合质子治疗。当对剩余的 190 例患者进行 IMPT 与 VMAT 比较时，有 148 例（66%）患者有资格接受质子治疗，42 例（19%）患者没有。对于这 42 例接受 VMAT 治疗的患者，生成了稳健的 PAT 计划。
与 IMPT 计划相比，PAT 计划提供了更好或相似的靶区覆盖。在 PAT 计划中，与 IMPT 计划相比，积分剂量显著降低了 18%，与 VMAT 计划相比，降低了 54%。PAT 降低了许多危及器官（OAR）的平均剂量，进一步降低了 NTCP 值。与 VMAT 相比，PAT 的 ΔNTCP 值在接受 VMAT 治疗的 42 例患者中有 32 例超过了 NIPP 阈值，这导致整个队列中有 180 例（81%）患者有资格接受质子治疗。
PAT 优于 IMPT 和 VMAT，导致 NTCP 值进一步降低，ΔNTCP 值显著增加，从而显著增加了选择接受质子治疗的 OPC 患者的比例。
