Marzi Simona, Iaccarino Giuseppe, Pasciuti Katia, Soriani Antonella, Benassi Marcello, Arcangeli Giorgio, Giovinazzo Giuseppe, Benassi Michaela, Marucci Laura
Laboratorio di Fisica Medica e Sistemi Esperti, Istituto Regina Elena, Rome, Italy.
Int J Radiat Oncol Biol Phys. 2009 Mar 15;73(4):1252-9. doi: 10.1016/j.ijrobp.2008.11.020.
To investigate dose-volume effects of salivary flow and the functional recovery over time, using salivary function data and different models of normal tissue complication probability (NTCP).
A total of 59 patients with head-and-neck cancer treated with intensity-modulated radiotherapy (IMRT) were analyzed in the present study. The toxicity was evaluated using the Radiation Therapy Oncology Group (RTOG) scale and salivary flows, both unstimulated (USF) and stimulated (SSF). The assessments were done before radiotherapy (RT) and at 3, 6, 12, 18, and 24 months after RT. Grade 3 toxicity was the primary endpoint. Analyses of toxicity incidence at 3, 6, and 12 months after RT were performed by both the Lyman-Kutcher-Burman (LKB) and relative seriality (S) models.
A significant correlation was found between the incidence of Grade 3 toxicity and the incidence of patients with a reduction in SSF to <25% of the pre-RT value. Better correlations resulted between the RTOG toxicity score and the dosimetric parameters, compared with USF/SSF. The TD(50), assessed by the LKB model, was 21.4, 27.8, and 41.6 Gy at 3, 6, and 12 months after RT, respectively. The TD(50), assessed by the S model, was 20.0, 26.3, and 40.0 Gy at 3, 6, and 12 months after RT, respectively.
Recovery of salivary gland function vs. time after RT took place mostly within 1 year after RT. The RTOG Grade 3 was a reliable score to perform the NTCP modeling. The choice of NTCP model had no influence on the accuracy of predictions.
利用唾液功能数据和不同的正常组织并发症概率（NTCP）模型，研究唾液流量的剂量 - 体积效应以及随时间的功能恢复情况。
本研究分析了59例接受调强放射治疗（IMRT）的头颈癌患者。使用放射治疗肿瘤学组（RTOG）量表以及静息唾液流量（USF）和刺激唾液流量（SSF）评估毒性。评估在放疗（RT）前以及RT后3、6、12、18和24个月进行。3级毒性是主要终点。采用莱曼 - 库彻 - 伯曼（LKB）模型和相对序列性（S）模型对RT后3、6和12个月的毒性发生率进行分析。
发现3级毒性发生率与SSF降低至RT前值的<25%的患者发生率之间存在显著相关性。与USF/SSF相比，RTOG毒性评分与剂量学参数之间的相关性更好。通过LKB模型评估的TD(50)在RT后3、6和12个月分别为21.4、27.8和41.6 Gy。通过S模型评估的TD(50)在RT后3、6和12个月分别为20.0、26.3和40.0 Gy。
放疗后唾液腺功能随时间的恢复大多发生在放疗后1年内。RTOG 3级是进行NTCP建模的可靠评分。NTCP模型的选择对预测准确性没有影响。
