Bucknell Nicholas, Hardcastle Nicholas, McIntosh Lachlan, Ball David, Hofman Michael S, Kron Tomas, Siva Shankar
Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Australia.
Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia; Molecular Imaging and Therapeutic Nuclear Medicine, Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia.
Pract Radiat Oncol. 2024 Nov-Dec;14(6):e480-e486. doi: 10.1016/j.prro.2024.04.014. Epub 2024 May 4.
Functional lung avoidance (FLA) radiation therapy is an evolving field. The aim of FLA planning is to reduce dose to areas of functioning lung, with comparable target coverage and dose to organs at risk. Multicriteria optimization (MCO) is a planning tool that may assist with FLA planning. This study assessed the feasibility of using MCO to adapt radiation therapy plans to avoid functional regions of lung that were identified using a Ga-4D-V/Q positron emission tomography/computed tomography.
A prospective clinical trial U1111-1138-4421 was performed in which patients had a Ga-4D-V/Q positron emission tomography/computed tomography before radiation treatment. Of the 72 patients enrolled in this trial, 38 patients had stage III non-small cell lung cancer and were eligible for selection into this planning study. Functional lung target volumes HF lung (highly functioning lung) and F lung (functional lung) were defined using the ventilated and perfused lung. Using knowledge-based planning, a baseline anatomic plan was created, and then a functional adapted plan was generated using multicriteria optimization. The primary aim was to spare dose to HF lung. Using the MCO tools, a clinician selected the final FLA plan. Dose to functional lung, target volumes, organs at risk and measures of plan quality were compared using standard statistical methods.
The HF lung volume was successfully spared in all patients. The F lung volume was successfully spared in 36 of the 38 patients. There were no clinically significant differences in dose to anatomically defined organs at risk. There were differences in the planning target volume near maximum and minimum doses. Across the entire population, there was a statistically significant reduction in the functional mean lung dose but not in the functional volume receiving 20 Gy. All trade-off decisions were made by the clinician.
Using MCO for FLA was achievable but did result in changes to planning target volume coverage. A distinct advantage in using MCO was that all decisions regarding the cost and benefits of FLA could be made in real time.
功能性肺避让（FLA）放射治疗是一个不断发展的领域。FLA计划的目的是在保证靶区覆盖和危及器官剂量相当的情况下，减少对功能肺区域的剂量。多标准优化（MCO）是一种可辅助FLA计划制定的计划工具。本研究评估了使用MCO来调整放射治疗计划以避让通过Ga-4D-V/Q正电子发射断层扫描/计算机断层扫描识别出的肺功能区域的可行性。
开展了一项前瞻性临床试验U1111-1138-4421，患者在放射治疗前进行了Ga-4D-V/Q正电子发射断层扫描/计算机断层扫描。在该试验入组的72例患者中，38例患有III期非小细胞肺癌，有资格入选本计划研究。利用通气肺和灌注肺定义了功能性肺靶区体积HF肺（高功能肺）和F肺（功能肺）。使用基于知识的计划制定，创建了一个基线解剖计划，然后使用多标准优化生成一个功能适应性计划。主要目的是减少对HF肺的剂量。使用MCO工具，临床医生选择最终的FLA计划。使用标准统计方法比较了对功能肺、靶区体积、危及器官的剂量以及计划质量指标。
所有患者的HF肺体积均成功得到保护。38例患者中有36例的F肺体积成功得到保护。对解剖学定义的危及器官的剂量无临床显著差异。计划靶区体积在最大和最小剂量附近存在差异。在整个人群中，功能性平均肺剂量有统计学显著降低，但接受20 Gy的功能体积未降低。所有权衡决策均由临床医生做出。
使用MCO进行FLA是可行的，但确实会导致计划靶区体积覆盖发生变化。使用MCO的一个明显优势是，关于FLA成本和效益的所有决策都可以实时做出。
