Rhee Dong Joo, Beddar Sam, Jaoude Joseph Abi, Sawakuchi Gabriel, Martin Rachael, Perles Luis, Yu Cenji, He Yulun, Court Laurence E, Ludmir Ethan B, Koong Albert C, Das Prajnan, Koay Eugene J, Taniguichi Cullen, Niedzielski Joshua S
Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Adv Radiat Oncol. 2023 Feb 2;8(4):101164. doi: 10.1016/j.adro.2022.101164. eCollection 2023 Jul-Aug.
To determine the dosimetric limitations of daily online adaptive pancreas stereotactic body radiation treatment by using an automated dose escalation approach.
We collected 108 planning and daily computed tomography (CT) scans from 18 patients (18 patients × 6 CT scans) who received 5-fraction pancreas stereotactic body radiation treatment at MD Anderson Cancer Center. Dose metrics from the original non-dose-escalated clinical plan (non-DE), the dose-escalated plan created on the original planning CT (DE-ORI), and the dose-escalated plan created on daily adaptive radiation therapy CT (DE-ART) were analyzed. We developed a dose-escalation planning algorithm within the radiation treatment planning system to automate the dose-escalation planning process for efficiency and consistency. In this algorithm, the prescription dose of the dose-escalation plan was escalated before violating any organ-at-risk (OAR) dose constraint. Dose metrics for 3 targets (gross target volume [GTV], tumor vessel interface [TVI], and dose-escalated planning target volume [DE-PTV]) and 9 OARs (duodenum, large bowel, small bowel, stomach, spinal cord, kidneys, liver, and skin) for the 3 plans were compared. Furthermore, we evaluated the effectiveness of the online adaptive dose-escalation planning process by quantifying the effect of the interfractional dose distribution variations among the DE-ART plans.
The median D dose to the GTV/TVI/DE-PTV was 33.1/36.2/32.4 Gy, 48.5/50.9/40.4 Gy, and 53.7/58.2/44.8 Gy for non-DE, DE-ORI, and DE-ART, respectively. Most OAR dose constraints were not violated for the non-DE and DE-ART plans, while OAR constraints were violated for the majority of the DE-ORI patients due to interfractional motion and lack of adaptation. The maximum difference per fraction in D, due to interfractional motion, was 2.5 ± 2.7 Gy, 3.0 ± 2.9 Gy, and 2.0 ± 1.8 Gy for the TVI, GTV, and DE-PTV, respectively.
Most patients require daily adaptation of the radiation planning process to maximally escalate delivered dose to the pancreatic tumor without exceeding OAR constraints. Using our automated approach, patients can receive higher target dose than standard of care without violating OAR constraints.
通过使用自动剂量递增方法确定每日在线自适应胰腺立体定向体部放射治疗的剂量学限制。
我们收集了来自18例患者（18例患者×6次CT扫描）的108次计划和每日计算机断层扫描（CT）图像，这些患者在MD安德森癌症中心接受了5分次的胰腺立体定向体部放射治疗。分析了原始未进行剂量递增的临床计划（非DE）、基于原始计划CT创建的剂量递增计划（DE-ORI）以及基于每日自适应放射治疗CT创建的剂量递增计划（DE-ART）的剂量指标。我们在放射治疗计划系统中开发了一种剂量递增计划算法，以实现剂量递增计划过程的自动化，从而提高效率和一致性。在该算法中，剂量递增计划的处方剂量在不违反任何危及器官（OAR）剂量约束的情况下进行递增。比较了这3个计划中3个靶区（大体靶体积[GTV]、肿瘤血管界面[TVI]和剂量递增计划靶体积[DE-PTV]）以及9个OAR（十二指肠、大肠、小肠、胃、脊髓、肾脏、肝脏和皮肤）的剂量指标。此外，我们通过量化DE-ART计划之间分次间剂量分布变化的影响，评估了在线自适应剂量递增计划过程的有效性。
非DE、DE-ORI和DE-ART计划中，GTV/TVI/DE-PTV的D剂量中位数分别为33.1/36.2/32.4 Gy、48.5/50.9/40.4 Gy和53.7/58.2/44.8 Gy。非DE和DE-ART计划大多未违反OAR剂量约束，而由于分次间运动和缺乏适应性，大多数DE-ORI患者的OAR约束被违反。由于分次间运动，TVI、GTV和DE-PTV每分次D的最大差异分别为2.5±2.7 Gy、3.0±2.9 Gy和2.0±1.8 Gy。
大多数患者需要每日对放射治疗计划过程进行调整，以在不超过OAR约束的情况下最大程度地递增胰腺肿瘤的照射剂量。使用我们的自动方法，患者可以在不违反OAR约束的情况下接受高于标准治疗的靶区剂量。
