Radiation Oncology Centre , Austin Health, Victoria , Australia.
Acta Oncol. 2013 Nov;52(8):1723-9. doi: 10.3109/0284186X.2012.759273. Epub 2013 Jan 15.
This study investigates the use of (18)F-fluoromisonidazole (FMISO) PET-guided radiotherapy dose painting for potentially overcoming the radioresistant effects of hypoxia in head and neck squamous cell carcinoma (HNSCC).
The study cohort consisted of eight patients with HNSCC who were planned for definitive radiotherapy. Hypoxic subvolumes were automatically generated on pre-radiotherapy FMISO PET scans. Three radiotherapy plans were generated for each patient: a standard (STD) radiotherapy plan to a dose of 70 Gy, a uniform dose escalation (UDE) plan to the standard target volumes to a dose of 84 Gy, and a hypoxia dose-painted (HDP) plan with dose escalation only to the hypoxic subvolume to 84 Gy. Plans were compared based on tumor control probability (TCP), normal tissue complication probability (NTCP), and uncomplicated tumor control probability (UTCP).
The mean TCP increased from 73% with STD plans to 95% with the use of UDE plans (p < 0.001) and to 93% with HDP plans (p < 0.001). The mean parotid NTCP increased from 26% to 44% with the use of UDE plans (p = 0.003), and the mean mandible NTCP increased from 2% to 27% with the use of UDE plans (p = 0.001). There were no statistically significant differences between any of the NTCPs between the STD plans and HDP plans. The mean UTCP increased from 48% with STD plans to 66% with HDP plans (p = 0.016) and dropped to 37% with UDE plans (p = 0.138).
Hypoxia-targeted radiotherapy dose painting for head and neck cancer using FMISO PET is technically feasible, increases the TCP without increasing the NTCP, and increases the UTCP. This approach is superior to uniform dose escalation.
本研究旨在探讨使用 18F-氟米索硝唑（FMISO）PET 引导的放疗剂量绘画来克服头颈部鳞状细胞癌（HNSCC）中缺氧的放射抵抗效应。
研究队列包括 8 例计划接受根治性放疗的 HNSCC 患者。在放疗前 FMISO PET 扫描上自动生成缺氧亚体积。为每位患者生成了三种放疗计划：标准（STD）放疗计划，剂量为 70Gy；标准靶区均匀剂量递增（UDE）计划，剂量为 84Gy；以及仅对缺氧亚体积进行剂量递增至 84Gy 的缺氧剂量绘画（HDP）计划。基于肿瘤控制概率（TCP）、正常组织并发症概率（NTCP）和无并发症肿瘤控制概率（UTCP）比较计划。
STD 计划的平均 TCP 从 73%增加到 UDE 计划的 95%（p<0.001）和 HDP 计划的 93%（p<0.001）。使用 UDE 计划时，平均腮腺 NTCP 从 26%增加到 44%（p=0.003），平均下颌骨 NTCP 从 2%增加到 27%（p=0.001）。STD 计划和 HDP 计划之间的任何 NTCP 均无统计学差异。STD 计划的平均 UTCP 从 48%增加到 HDP 计划的 66%（p=0.016），而 UDE 计划的 UTCP 下降至 37%（p=0.138）。
使用 FMISO PET 对头颈部癌症进行缺氧靶向放疗剂量绘画在技术上是可行的，在不增加 NTCP 的情况下增加 TCP，并增加 UTCP。这种方法优于均匀剂量递增。
