A multi-arc and constant-energy-per-arc treatment planning method for efficient proton arc therapy

IF 3.2 2区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Medical physics Pub Date : 2025-09-22 DOI:10.1002/mp.18089

Jiangjun Ma, Ya-Nan Zhu, Yuting Lin, Min Tang, Hao Gao

{"title":"A multi-arc and constant-energy-per-arc treatment planning method for efficient proton arc therapy","authors":"Jiangjun Ma, Ya-Nan Zhu, Yuting Lin, Min Tang, Hao Gao","doi":"10.1002/mp.18089","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>Proton arc therapy is an emerging proton modality with enhanced dose and linear energy transfer (LET) conformality to treatment targets. However, its delivery efficiency can be negatively impacted by frequent energy changes.</p>\n </section>\n \n <section>\n \n <h3> Purpose</h3>\n \n <p>This work will develop a novel proton arc treatment planning method that has constant energy and thus does not require energy changes per arc, that is, a multi-arc and constant-energy-per-arc approach, for achieving efficient delivery of proton arc while optimizing its plan quality.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>The proposed method is based on a novel block orthogonal matching pursuit (BOMP) optimization algorithm. The optimization process involves an iterative approach that alternates between BOMP-based energy selection and the optimization of spot weights on the selected arcs subject to the minimum-monitor-unit deliverability constraint. For method validation, the proposed BOMP is compared with (1) the heuristic-search (HS) method, in which each arc is optimized individually and then arcs with the best plan quality are jointly selected to optimize the final plan; (2) the conventional (CONV) method, which has a variable-energy arc, serving as the ground truth for plan quality; (3) the energy layer optimization (ELO) method, which minimizes the number of energy jumps for CONV.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>BOMP had better plan quality than HS for multi-arc planning (e.g., 5-arc) in this work, which validates the efficacy of the BOMP method. Compared to IMPT, BOMP5 offers superior plan quality while also being comparable in total plan delivery time. For example, in a liver case, BOMP5 increased the conformity index (CI) from 0.80 to 0.86, reduced the max target dose from 130.1% to 116.4%, and also decreased the total plan delivery time from 354.4 to 259.9 s. Compared to CONV and ELO, BOMP substantially reduced energy layer switching time without sacrificing the plan quality. For example, compared to CONV, BOMP reduced the optimization objective value from 0.358–0.231, reduced max target dose from 116.3% to 110.8%, reduced the ≥10 Gy volume of brainstem from 0.84cc to 0.43cc and improved the CI from 0.83 to 0.84 for a head-and-neck case. Compared to CONV, the energy layer switching times for the head-and-neck case, liver case, and lung case have been significantly reduced from 759.4, 1918.6, and 916.2 to 2.8 s, respectively. And the total plan delivery time significantly reduced from 790.7 to 149.2 s, 2184.9 to 259.9 s, and 1017.6 to 125.0 s, respectively.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>A novel multi-arc and constant-energy-per-arc proton arc treatment planning method is proposed that can eliminate the need of energy switching per arc, without sacrificing the plan quality, compared to CONV and ELO.</p>\n </section>\n </div>","PeriodicalId":18384,"journal":{"name":"Medical physics","volume":"52 10","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Medical physics","FirstCategoryId":"3","ListUrlMain":"https://aapm.onlinelibrary.wiley.com/doi/10.1002/mp.18089","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}

引用次数: 0

Abstract

Background

Proton arc therapy is an emerging proton modality with enhanced dose and linear energy transfer (LET) conformality to treatment targets. However, its delivery efficiency can be negatively impacted by frequent energy changes.

Purpose

This work will develop a novel proton arc treatment planning method that has constant energy and thus does not require energy changes per arc, that is, a multi-arc and constant-energy-per-arc approach, for achieving efficient delivery of proton arc while optimizing its plan quality.

Methods

The proposed method is based on a novel block orthogonal matching pursuit (BOMP) optimization algorithm. The optimization process involves an iterative approach that alternates between BOMP-based energy selection and the optimization of spot weights on the selected arcs subject to the minimum-monitor-unit deliverability constraint. For method validation, the proposed BOMP is compared with (1) the heuristic-search (HS) method, in which each arc is optimized individually and then arcs with the best plan quality are jointly selected to optimize the final plan; (2) the conventional (CONV) method, which has a variable-energy arc, serving as the ground truth for plan quality; (3) the energy layer optimization (ELO) method, which minimizes the number of energy jumps for CONV.

Results

BOMP had better plan quality than HS for multi-arc planning (e.g., 5-arc) in this work, which validates the efficacy of the BOMP method. Compared to IMPT, BOMP5 offers superior plan quality while also being comparable in total plan delivery time. For example, in a liver case, BOMP5 increased the conformity index (CI) from 0.80 to 0.86, reduced the max target dose from 130.1% to 116.4%, and also decreased the total plan delivery time from 354.4 to 259.9 s. Compared to CONV and ELO, BOMP substantially reduced energy layer switching time without sacrificing the plan quality. For example, compared to CONV, BOMP reduced the optimization objective value from 0.358–0.231, reduced max target dose from 116.3% to 110.8%, reduced the ≥10 Gy volume of brainstem from 0.84cc to 0.43cc and improved the CI from 0.83 to 0.84 for a head-and-neck case. Compared to CONV, the energy layer switching times for the head-and-neck case, liver case, and lung case have been significantly reduced from 759.4, 1918.6, and 916.2 to 2.8 s, respectively. And the total plan delivery time significantly reduced from 790.7 to 149.2 s, 2184.9 to 259.9 s, and 1017.6 to 125.0 s, respectively.

Conclusion

A novel multi-arc and constant-energy-per-arc proton arc treatment planning method is proposed that can eliminate the need of energy switching per arc, without sacrificing the plan quality, compared to CONV and ELO.

Abstract Image

查看原文本刊更多论文

一种多弧、每弧能量恒定的高效质子弧治疗计划方法

质子弧治疗是一种新兴的质子治疗方式，具有增强剂量和与治疗目标的线性能量转移（LET）一致性。然而，频繁的能量变化会对其输送效率产生负面影响。本工作将开发一种新的质子弧治疗计划方法，该方法具有恒定能量，因此不需要每弧能量变化，即多弧和每弧恒定能量的方法，以实现质子弧的高效输送，同时优化其计划质量。方法基于一种新的块正交匹配追踪（BOMP）优化算法。优化过程包括一种迭代方法，在基于bomp的能量选择和受最小监测单元交付能力约束的选定弧线上的点权重优化之间交替进行。为验证方法，将所提BOMP与启发式搜索（HS）方法进行比较，启发式搜索方法对每个弧线进行单独优化，然后联合选择方案质量最佳的弧线进行最终方案优化；(2)常规（CONV）方法，该方法具有变能量弧，作为平面图质量的基础真值；(3)能量层优化（energy layer optimization， ELO）方法，最大限度地减少了CONV的能量跳跃次数。结果BOMP在本研究中对于多弧规划（如5弧）的规划质量优于HS，验证了BOMP方法的有效性。与IMPT相比，BOMP5提供了更高的计划质量，同时在总计划交付时间上也具有可比性。例如，在肝脏病例中，BOMP5将符合性指数（CI）从0.80提高到0.86，将最大目标剂量从130.1%降低到116.4%，将总计划交付时间从354.4 s降低到259.9 s。与CONV和ELO相比，BOMP在不牺牲计划质量的情况下大大减少了能量层切换时间。例如，与CONV相比，BOMP将优化目标值从0.358-0.231降低，最大靶剂量从116.3%降低到110.8%，脑干≥10 Gy体积从0.84cc降低到0.43cc，头颈部病例CI从0.83提高到0.84。与CONV相比，头颈部病例、肝脏病例和肺部病例的能量层切换时间分别从759.4秒、1918.6秒和916.2秒显著降低到2.8秒。总方案交付时间分别从790.7 s减少到149.2 s，从2184.9 s减少到259.9 s，从1017.6 s减少到125.0 s。结论与CONV和ELO相比，提出了一种新的多弧、每弧能量恒定的质子电弧治疗计划方法，在不牺牲计划质量的前提下，消除了每弧能量转换的需要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Medical physics 医学-核医学

CiteScore

6.80

自引率

15.80%

发文量

660

审稿时长

1.7 months

期刊介绍： Medical Physics publishes original, high impact physics, imaging science, and engineering research that advances patient diagnosis and therapy through contributions in 1) Basic science developments with high potential for clinical translation 2) Clinical applications of cutting edge engineering and physics innovations 3) Broadly applicable and innovative clinical physics developments Medical Physics is a journal of global scope and reach. By publishing in Medical Physics your research will reach an international, multidisciplinary audience including practicing medical physicists as well as physics- and engineering based translational scientists. We work closely with authors of promising articles to improve their quality.