Rechner Laura A, Felter Mette, Bekke Susanne, Biancardo Susan, Rønjom Marianne F, Pedersen Mette, Sjöström David, Chen Inna M, Sibolt Patrik
Department of Oncology, Copenhagen University Hospital-Herlev and Gentofte, Herlev, DNK.
Cureus. 2024 Sep 1;16(9):e68386. doi: 10.7759/cureus.68386. eCollection 2024 Sep.
Pancreatic cancer is one of the most challenging tumor sites to treat safely and effectively with radiotherapy due to the anatomical location and aggressiveness of the disease. One modality that has shown promising results, which our institution has been employing, is online adaptive stereotactic radiotherapy using a magnetic resonance-guided linear accelerator (MR-linac). However, due to unforeseen circumstances regarding our MR-linac, it was necessary for our institution to use an alternative treatment technique. In this case report, we describe our experience using our ring-gantry linac equipped with an advanced cone-beam computed tomography (CBCT) system to treat a 61-year-old patient with advanced pancreatic cancer with CBCT-guided online adaptive stereotactic radiotherapy. In a short time period of four weeks, we prepared for this case by training with the surface scanning motion management system and developing procedures for planning and adaptation. The patient was prescribed 24 Gy in three fractions, with a risk-adapted approach using strict organ-at-risk (OAR) constraints. Daily CBCT was used for online adaptation of the plan, and the superior plan (non-adapted or adapted) was selected for treatment. For this patient, the adapted plan was chosen for all three fractions, due to OAR constraints being violated in the non-adapted plan. In summary, we found that for this patient, high-quality CBCT guidance for daily re-contouring, in combination with motion management, enabled the use of daily adaptive radiotherapy to safely deliver stereotactic radiotherapy. The results from this case report are promising, and CBCT-guided online adaptive stereotactic radiotherapy for pancreatic cancer warrants further investigation in more patients.
由于胰腺癌的解剖位置和侵袭性，放射治疗要安全有效地治疗该肿瘤部位极具挑战性。我们机构一直在采用的一种显示出有前景结果的治疗方式，是使用磁共振引导直线加速器（MR直线加速器）进行在线自适应立体定向放射治疗。然而，由于我们的MR直线加速器出现了不可预见的情况，我们机构有必要使用替代治疗技术。在本病例报告中，我们描述了使用配备先进锥形束计算机断层扫描（CBCT）系统的环形机架直线加速器，对一名61岁晚期胰腺癌患者进行CBCT引导的在线自适应立体定向放射治疗的经验。在短短四周的时间里，我们通过使用表面扫描运动管理系统进行训练以及制定计划和适应性程序，为该病例做准备。患者被处方给予24 Gy分三次照射，采用风险适应方法并严格限制危及器官（OAR）。每日使用CBCT进行计划的在线适应性调整，并选择最优计划（未适应或适应后的）进行治疗。对于该患者，由于未适应计划中违反了OAR限制，所以三次照射均选择了适应后的计划。总之，我们发现对于该患者，每日重新轮廓勾画的高质量CBCT引导与运动管理相结合，使得能够使用每日自适应放射治疗来安全地进行立体定向放射治疗。本病例报告的结果很有前景，CBCT引导的在线自适应立体定向放射治疗在胰腺癌治疗方面值得在更多患者中进一步研究。
