Chua Daniel T T, Wu Shao-Xiong, Lee Victor, Tsang Janice
Department of Clinical Oncology, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, PR China.
Head Neck Oncol. 2009 May 23;1:13. doi: 10.1186/1758-3284-1-13.
Local failure is an important cause of morbidity and mortality in nasopharyngeal carcinoma (NPC). Although surgery or brachytherapy may be feasible in selected cases, most patients with local failure require external beam re-irradiation. Stereotactic radiation using single or multiple fractions have been employed in re-irradiation of NPC, but the optimal fractionation scheme and dose are not clear.
Records of 125 NPC patients who received salvage stereotactic radiation were reviewed. A matched-pair design was used to select patients with similar prognostic factors who received stereotactic re-irradiation using single fraction (SRS) or multiple fractions (SRM). Eighty-six patients were selected with equal number in SRS and SRM groups. All patients were individually matched for failure type (persistent or recurrent), rT stage (rT1-2 or rT3-4), and tumor volume (< or = 5 cc, >5-10 cc, or >10 cc). Median dose was 12.5 Gy in single fraction by SRS, and 34 Gy in 2-6 fractions by SRM.
Local control rate was better in SRM group although overall survival rates were similar. One- and 3-year local failure-free rates were 70% and 51% in SRS group compared with 91% and 83% in SRM group (p = 0.003). One- and 3-year overall survival rates were 98% and 66% in SRS group compared with 78% and 61% in SRM group (p = 0.31). The differences in local control were mainly observed in recurrent or rT2-4 disease. Incidence of severe late complications was 33% in SRS group vs. 21% in SRM group, including brain necrosis (16% vs. 12%) and hemorrhage (5% vs. 2%).
Our study showed that SRM was superior to SRS in salvaging local failures of NPC, especially in the treatment of recurrent and rT2-4 disease. In patient with local failure of NPC suitable for stereotactic re-irradiation, use of fractionated treatment is preferred.
局部失败是鼻咽癌（NPC）发病和死亡的重要原因。尽管在某些特定病例中手术或近距离放疗可能可行，但大多数局部失败的患者需要进行外照射再程放疗。立体定向放疗采用单次或多次分割已应用于NPC的再程放疗，但最佳分割方案和剂量尚不清楚。
回顾了125例接受挽救性立体定向放疗的NPC患者的记录。采用配对设计选择具有相似预后因素的患者，这些患者接受单次分割（SRS）或多次分割（SRM）的立体定向再程放疗。选择了86例患者，SRS组和SRM组人数相等。所有患者根据失败类型（持续性或复发性）、rT分期（rT1-2或rT3-4）和肿瘤体积（≤5cc、>5-10cc或>10cc）进行个体匹配。SRS组单次分割的中位剂量为12.5Gy，SRM组2-6次分割的中位剂量为34Gy。
尽管总生存率相似，但SRM组的局部控制率更好。SRS组1年和3年局部无失败率分别为70%和51%，而SRM组为91%和83%（p=0.003）。SRS组1年和3年总生存率分别为98%和66%，而SRM组为78%和61%（p=0.31）。局部控制的差异主要在复发性或rT2-4期疾病中观察到。SRS组严重晚期并发症的发生率为33%，而SRM组为21%，包括脑坏死（16%对12%）和出血（5%对2%）。
我们的研究表明，在挽救NPC的局部失败方面，SRM优于SRS，尤其是在治疗复发性和rT2-4期疾病时。对于适合立体定向再程放疗的NPC局部失败患者，首选分割治疗。
