Hill Colin S, Fu Wei, Hu Chen, Sehgal Shuchi, Reddy Abhinav V, He Jin, Herman Joseph M, Meyer Jeffrey J, Zaheer Atif, Narang Amol K
Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Pract Radiat Oncol. 2022 May-Jun;12(3):215-225. doi: 10.1016/j.prro.2022.01.005. Epub 2022 Feb 7.
In patients with borderline resectable or locally advanced pancreatic adenocarcinoma (BRPC/LAPC), local failure rates after resection remain significant, even in the setting of neoadjuvant chemotherapy and radiation. Suboptimal local control may relate to variable radiation target delineation, as no consensus exists around clinical tumor volume (CTV) design in this context. In the surgical literature, recent attention has been given to the "triangle" volume (TV) as a source of subclinical, residual disease. To understand whether the TV can inform optimal CTV design, we mapped locoregional failures after resection in a large cohort of patients with BRPC/LAPC and compared locations of failure to the TV.
Patients with BRPC/LAPC of the head or neck diagnosed between 2016 AND 2019 who developed locoregional failure after surgery, neoadjuvant chemotherapy, and radiation were identified. Descriptive statistics were generated to report the frequency of locoregional failures located within the TV and the frequency of new vascular involvement at time of failure, compared with vascular involvement at diagnosis. Additionally, dosimetric coverage of the TV with the preoperative radiation plan that had been used was assessed.
In 31 patients who experienced locoregional failure, the centroid of failure was located within the TV in 28 cases (90%). Extent of vascular involvement at time of locoregional failure included vasculature that had not been involved at diagnosis in 13 cases (42%). The preoperative radiation plan that had been used provided a median V33 Gy and V25 Gy of the TV of only 53% (interquartile range, 34%-72%) and 70% (IQR, 48%-85%), respectively.
The TV encompassed the vast majority of locoregional failures, but dosimetric coverage of the TV was poor when only targeting gross disease and the full circumference of involved vasculature. As such, the TV may better serve as a basis for CTV design in patients with BRPC/LAPC undergoing neoadjuvant radiation.
在边缘可切除或局部晚期胰腺腺癌（BRPC/LAPC）患者中，即使在新辅助化疗和放疗的情况下，切除术后的局部失败率仍然很高。局部控制不佳可能与放疗靶区勾画的差异有关，因为在这种情况下，临床肿瘤体积（CTV）设计尚无共识。在外科文献中，最近人们将“三角”体积（TV）视为亚临床残留疾病的来源。为了了解TV是否能为优化CTV设计提供依据，我们在一大群BRPC/LAPC患者中绘制了切除术后的局部区域失败情况，并将失败部位与TV进行了比较。
确定2016年至2019年间诊断为头颈部BRPC/LAPC且在手术、新辅助化疗和放疗后发生局部区域失败的患者。生成描述性统计数据，以报告位于TV内的局部区域失败频率以及失败时新血管受累的频率，并与诊断时的血管受累情况进行比较。此外，评估了所使用的术前放疗计划对TV的剂量覆盖情况。
在31例发生局部区域失败的患者中，28例（90%）的失败中心位于TV内。局部区域失败时血管受累的范围包括13例（42%）诊断时未受累的血管。所使用的术前放疗计划对TV的V33 Gy和V25 Gy的中位数分别仅为53%（四分位间距，34%-72%）和70%（四分位间距，48%-85%）。
TV涵盖了绝大多数局部区域失败情况，但仅针对大体疾病和受累血管的整个周长进行放疗时，TV的剂量覆盖较差。因此，TV可能更适合作为接受新辅助放疗的BRPC/LAPC患者CTV设计的基础。
