Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
Department of Physics and Technology, University of Bergen, Bergen, Norway.
Phys Med. 2024 Jul;123:103404. doi: 10.1016/j.ejmp.2024.103404. Epub 2024 Jun 8.
Image-driven dose escalation to tumor subvolumes has been proposed to improve treatment outcome in head and neck cancer (HNC). We used F-fluorodeoxyglucose (FDG) positron emission tomography (PET) acquired at baseline and into treatment (interim) to identify biologic target volumes (BTVs). We assessed the feasibility of interim dose escalation to the BTV with proton therapy by simulating the effects to organs at risk (OARs).
We used the semiautomated just-enough-interaction (JEI) method to identify BTVs in F-FDG-PET images from nine HNC patients. Between baseline and interim FDG-PET, patients received photon radiotherapy. BTV was identified assuming that high standardized uptake value (SUV) at interim reflected tumor radioresistance. Using Eclipse (Varian Medical Systems), we simulated a 10% (6.8 Gy(RBE)) and 20% (13.6 Gy(RBE)) dose escalation to the BTV with protons and compared results with proton plans without dose escalation.
At interim F-FDG-PET, radiotherapy resulted in reduced SUV compared to baseline. However, spatial overlap between high-SUV regions at baseline and interim allowed for BTV identification. Proton therapy planning demonstrated that dose escalation to the BTV was feasible, and except for some 20% dose escalation plans, OAR doses did not significantly increase.
Our in silico analysis demonstrated the potential for interim F-FDG-PET response-adaptive dose escalation to the BTV with proton therapy. This approach may give more efficient treatment to HNC with radioresistant tumor subvolumes without increasing normal tissue toxicity. Studies in larger cohorts are required to determine the full potential for interim F-FDG-PET-guided dose escalation of proton therapy in HNC.
已提出针对肿瘤亚体积的图像驱动剂量递增，以改善头颈部癌症（HNC）的治疗效果。我们使用基线和治疗期间（中期）获得的 F-氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）来识别生物靶区（BTV）。我们通过模拟对危及器官（OAR）的影响，评估了质子治疗对 BTV 进行中期剂量递增的可行性。
我们使用半自动充分交互（JEI）方法在 9 名 HNC 患者的 F-FDG-PET 图像中识别 BTV。在基线和中期 FDG-PET 之间，患者接受光子放射治疗。假设中期高标准化摄取值（SUV）反映了肿瘤的放射抗性，因此识别了 BTV。使用 Eclipse（Varian Medical Systems），我们模拟了对 BTV 进行 10%（6.8 Gy[RBE]）和 20%（13.6 Gy[RBE]）的剂量递增，并将结果与没有剂量递增的质子计划进行了比较。
在中期 F-FDG-PET 中，与基线相比，放射治疗导致 SUV 降低。然而，基线和中期高 SUV 区域的空间重叠允许识别 BTV。质子治疗计划表明，对 BTV 进行剂量递增是可行的，除了一些 20%的剂量递增计划外，OAR 剂量没有显著增加。
我们的计算机分析表明，对于质子治疗，使用中期 F-FDG-PET 反应适应性剂量递增来治疗 BTV 具有潜力。这种方法可能会在不增加正常组织毒性的情况下，对头颈部具有放射性抗性肿瘤亚体积的癌症提供更有效的治疗。需要在更大的队列中进行研究，以确定在 HNC 中使用中期 F-FDG-PET 指导的质子治疗剂量递增的全部潜力。
