Megahed Romy, Prabhu Arpan V, Mack Delanie P, Gholami Somayeh, Samanta Santanu, Patel Mausam, Lewis Gary D
Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 W. Markham St., #771, Little Rock, AR 72205-7199, United States.
Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 W. Markham St., #771, Little Rock, AR 72205-7199, United States.
Oral Oncol. 2024 May;152:106778. doi: 10.1016/j.oraloncology.2024.106778. Epub 2024 Mar 30.
PURPOSE/OBJECTIVE(S): Pulsed reduced dose rate (PRDR) radiation (RT) is a re-irradiation (Re-RT) technique that potentially overcomes dose/volume constraints in the setting of previous RT. There is minimal data for its use for recurrent or secondary primary head and neck squamous cell carcinoma (HNSCC). In this study, we report preliminary data from our institution of a consecutive cohort of HNSCC patients who received PRDR Re-RT.
MATERIALS/METHODS: Nine patients received PRDR Re-RT from August 2020 to January 2023 and had analyzable data. Intensity modulated RT was used for treatment delivery and a wait time between 20 cGy arc/helical deliveries was used to achieve the effective low dose rate. Data collected included patient demographic information, prior interventions, diagnosis, radiation therapy dose and fractionation, progression free survival, overall survival, and toxicity rates.
The median time to PRDR-RT from completion of initial RT was 13 months (range, 6-50 months). All but one patient underwent salvage surgery prior to PRDR-RT. The median follow-up after Re-RT was 7 months. The median OS from PRDR-RT was 7 months (range, 1-32 months). Median PFS was 7 months (range, 1-32 months). One patient (11.1 %) had acute grade 3 toxicity, and two patients (22.2 %) had late grade 3 toxicities. There were no grade 4+ toxicities.
PRDR Re-RT is a feasible treatment strategy for patients with recurrent or second primary HNSCC. Initial findings from this retrospective review suggest reasonable survival outcomes and potentially improved toxicity; prospective data is needed to establish the safety and efficacy of this technique.
脉冲式低剂量率（PRDR）放疗是一种再程放疗技术，有可能克服既往放疗中的剂量/体积限制。关于其用于复发性或二次原发性头颈部鳞状细胞癌（HNSCC）的数据极少。在本研究中，我们报告了我院一组接受PRDR再程放疗的HNSCC患者的初步数据。
2020年8月至2023年1月期间，9例患者接受了PRDR再程放疗且有可分析数据。采用调强放疗进行治疗，并在每次20 cGy的弧形/螺旋照射之间设置等待时间以实现有效的低剂量率。收集的数据包括患者人口统计学信息、既往干预措施、诊断、放疗剂量和分割、无进展生存期、总生存期以及毒性发生率。
从初始放疗结束到进行PRDR放疗的中位时间为13个月（范围6 - 50个月）。除1例患者外，所有患者在PRDR放疗前均接受了挽救性手术。再程放疗后的中位随访时间为7个月。PRDR放疗后的中位总生存期为7个月（范围1 - 32个月）。中位无进展生存期为7个月（范围1 - 32个月）。1例患者（11.1%）出现急性3级毒性，2例患者（22.2%）出现晚期3级毒性。无4级及以上毒性。
PRDR再程放疗是复发性或二次原发性HNSCC患者的一种可行治疗策略。这项回顾性研究的初步结果显示出合理的生存结果和潜在改善的毒性；需要前瞻性数据来确定该技术的安全性和有效性。
