Department of Radiation Oncology, Riverside Methodist Hospital, OhioHealth, Columbus, USA.
Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, USA.
Radiother Oncol. 2021 Oct;163:39-45. doi: 10.1016/j.radonc.2021.07.023. Epub 2021 Jul 29.
Prior in silico simulations of studies of Temporally Feathered Radiation Therapy (TFRT) have demonstrated potential reduction in normal tissue toxicity. This R-IDEAL Stage 1/2A study seeks to demonstrate the first-in-human implementation of TFRT in treating patients with head and neck squamous cell carcinoma (HNSCC).
Patients with HNSCC treated with definitive radiation therapy were eligible (70 Gy in 35 fractions) were eligible. The primary endpoint was feasibility of TFRT planning as defined by radiation start within 15 business days of CT simulation. Secondary endpoints included estimates of acute grade 3-5 toxicity.
The study met its accrual goal of 5 patients. TFRT plans were generated in four of the five patients within 15 business days of CT simulation, therefore meeting the primary endpoint. One patient was not treated with TFRT at the physician's discretion, though the TFRT plan had been generated within sufficient time from the CT simulation. For patients who received TFRT, the median time from CT simulation to radiation start was 10 business days (range 8-15). The average time required for radiation planning was 6 business days. In all patients receiving TFRT, each subplan and every daily fraction was delivered in the correct sequence without error. The OARs feathered included: oral cavity, each submandibular gland, each parotid gland, supraglottis, and posterior pharyngeal wall (OAR pharynx). Prescription dose PTV coverage (>95%) was ensured in each TFRT subplan and the composite TFRT plan. One of five patients developed an acute grade 3 toxicity.
This study demonstrates the first-in-human implementation of TFRT (R-IDEAL Stage 1), proving its feasibility in the modern clinical workflow. Additionally, assessments of acute toxicities and dosimetric comparisons to a standard radiotherapy plan were described (R-IDEAL Stage 2a).
先前的 temporally feathered radiation therapy（TFRT）模拟研究表明，这种治疗方法可能会降低正常组织的毒性。这项 R-IDEAL 阶段 1/2A 研究旨在证明 TFRT 首次在治疗头颈部鳞状细胞癌（HNSCC）患者中的人体实施。
接受根治性放疗的 HNSCC 患者符合条件（70Gy 分 35 次）。主要终点是根据 CT 模拟后 15 个工作日内开始放疗来定义的 TFRT 计划的可行性。次要终点包括急性 3-5 级毒性的估计。
该研究达到了 5 名患者的入组目标。在 CT 模拟后 15 个工作日内，有 4 名患者生成了 TFRT 计划，因此达到了主要终点。一名患者因医生的决定未接受 TFRT 治疗，尽管已经在足够的时间内从 CT 模拟生成了 TFRT 计划。对于接受 TFRT 的患者，从 CT 模拟到放疗开始的中位时间为 10 个工作日（范围为 8-15）。放射计划所需的平均时间为 6 个工作日。在所有接受 TFRT 的患者中，每个子计划和每个每日分次都没有错误地按正确顺序交付。被 feathered 的 OAR 包括：口腔、每个下颌下腺、每个腮腺、声门上区和后咽壁（OAR 咽）。在每个 TFRT 子计划和复合 TFRT 计划中，都确保了靶区 PTV 覆盖（>95%）。5 名患者中有 1 名发生急性 3 级毒性。
这项研究首次在人体中实施了 TFRT（R-IDEAL 阶段 1），证明了它在现代临床工作流程中的可行性。此外，还描述了对急性毒性的评估和与标准放疗计划的剂量学比较（R-IDEAL 阶段 2a）。
