Teo Peter M L, Leung Sing Fai, Tung Stewart Y, Zee Benny, Sham Jonathan S T, Lee Anne W M, Lau Wai Hon, Kwan Wing Hong, Leung To Wai, Chua Daniel, Sze Wai Man, Au Joseph S K, Yu Kwok Hung, O Sai Ki, Kwong Dora, Yau Tsz Kok, Law Stephen C K, Sze Wing Kin, Au Gordon, Chan Anthony T C
Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, China.
Radiother Oncol. 2006 Apr;79(1):27-33. doi: 10.1016/j.radonc.2006.03.012. Epub 2006 Apr 19.
To define the dose-response relationship of nasopharyngeal carcinoma (NPC) above the conventional tumoricidal dose level of 66 Gy when the basic radiotherapy (RT) course was given by the 2D Ho's technique.
Data from all five regional cancer centers in Hong Kong were pooled for this retrospective study. All patients (n = 2426) were treated with curative-intent RT with or without chemotherapy between 1996 and 2000 with the basic RT course using the Ho's technique. The primary endpoint was local control. The prognostic significance of dose-escalation ('boost') after 66 Gy, T-stage, N-stage, use of chemotherapy, sex and age (< or =40 years vs >40 years) was studied. Both univariate and multivariate analyses were performed.
On multivariate analysis, T-stage (P < 0.01; hazard ratio [HR], 1.58) and optimal boost (P = 0.01; HR, 0.34) were the only significant factors affecting local failure for the whole study population, and for the population of patients treated by radiotherapy alone, but not for patients who also received chemotherapy. The following were independent determinants of local failure for patient groups with different T-stages treated by radiotherapy alone: use of a boost in T1/T2a disease (P = 0.01; HR, 0.33); use of a boost (P < 0.01; HR, 0.60) and age (P = 0.01; HR, 1.02) in T3/T4 tumors. Among patients with T2b tumors treated by radiotherapy alone and given a boost, the use of a 20 Gy-boost gave a lower local failure rate than a 10 Gy-boost. There was no apparent excess mortality attributed to RT complications.
Within the context of a multi-center retrospective study, dose-escalation above 66 Gy significantly improved local control for T1/T2a and T3/4 tumors when the primary RT course was based on the 2D Ho's technique without additional chemotherapy. 'Boosting' in NPC warrants further investigation. Caution should be taken when boosting is considered because of possible increase in radiation toxicity.
当采用二维何氏技术进行基础放射治疗（RT）疗程时，确定鼻咽癌（NPC）在常规肿瘤致死剂量水平66 Gy以上的剂量 - 反应关系。
汇总香港所有五个区域癌症中心的数据进行这项回顾性研究。所有患者（n = 2426）在1996年至2000年间接受了根治性放疗，放疗过程中有的联合化疗，有的未联合化疗，基础放疗疗程采用何氏技术。主要终点是局部控制。研究了66 Gy后剂量递增（“强化”）、T分期、N分期、化疗的使用、性别和年龄（≤40岁与＞40岁）的预后意义。进行了单因素和多因素分析。
多因素分析显示，对于整个研究人群以及仅接受放疗的患者群体，T分期（P < 0.01；风险比[HR]，1.58）和最佳强化（P = 0.01；HR，0.34）是影响局部复发的唯一显著因素，但对于同时接受化疗的患者则不然。对于仅接受放疗的不同T分期患者群体，以下是局部复发的独立决定因素：T1/T2a期疾病采用强化（P = 0.01；HR，0.33）；T3/T4期肿瘤采用强化（P < 0.01；HR，0.60）和年龄（P = 0.01；HR，1.02）。在仅接受放疗并进行强化的T2b期肿瘤患者中，采用20 Gy强化的局部复发率低于10 Gy强化。没有明显因放疗并发症导致的额外死亡率。
在多中心回顾性研究的背景下，当基础放疗疗程基于二维何氏技术且无额外化疗时，66 Gy以上的剂量递增显著改善了T1/T2a和T3/4期肿瘤的局部控制。鼻咽癌的“强化”值得进一步研究。考虑强化时应谨慎，因为可能会增加放射毒性。
