Allal A S, de Pree C, Dulguerov P, Bieri S, Maire D, Kurtz J M
Division of Radiation Oncology, University Hospital, Geneva, Switzerland.
Int J Radiat Oncol Biol Phys. 1999 Aug 1;45(1):41-5. doi: 10.1016/s0360-3016(99)00138-8.
To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas.
152 patients treated with radical RT for oropharyngeal carcinomas between 1979 and 1996 were retrospectively analyzed. According to the American Joint Committee on Cancer (AJCC) staging system, there were 6/30/43/73 stages III/III/IV. Sixty-one patients were treated with a conventional RT schedule (median dose 70 Gy in 35 fractions), and 91 patients with either of two 5/5.5-week accelerated RT schedules (median dose 69.6-69.9 Gy in 41 fractions). Discounting weekends, RT was interrupted for 2 consecutive days or more in 53 patients (median duration 11 days, range 2-97), including 67% of the patients in the conventional RT group and 13% in the accelerated RT group. Median follow-up for surviving patients was 55 months (range 23-230). The Cox proportional hazards model was used for the multivariate analysis of factors influencing locoregional control.
In univariate analysis, factors associated with a significant decrease in locoregional control included WHO performance status > or =1, advanced AJCC stages (III and IV), conventional RT fractionation, overall treatment time > or =44 days (median), and RT interruption. In the multivariate analysis, when introduced into the model individually, the three significant therapeutic factors remained significant after adjustment for the forced clinical variables. However, when the three therapeutic factors were introduced together into the model, beside the AJCC stage (P = 0.017), only RT interruption remained a significant independent adverse prognostic factor (P = 0.026).
This multivariate analysis highlights the potential negative impact of treatment gaps on locoregional control in oropharyngeal carcinomas. This suggests that treatment interruption may be an even more important parameter than the type of RT schedule per se. Thus, when assessing the relative merit of two RT schedules, inclusion of the other therapeutic factors in a multivariate model is mandatory in order to avoid misinterpretation of the results.
评估与传统分割放疗相比，加速放疗中断治疗对口咽癌患者局部区域控制潜在获益的影响。
回顾性分析了1979年至1996年间接受根治性放疗的152例口咽癌患者。根据美国癌症联合委员会（AJCC）分期系统，有6/30/43/73例为III/III/IV期。61例患者接受传统放疗方案（35次分割，中位剂量70 Gy），91例患者接受两种5/5.5周加速放疗方案之一（41次分割，中位剂量69.6 - 69.9 Gy）。不计周末，53例患者放疗中断连续2天或更长时间（中位持续时间11天，范围2 - 97天），其中传统放疗组患者占67%，加速放疗组患者占13%。存活患者的中位随访时间为55个月（范围23 - 230个月）。采用Cox比例风险模型对影响局部区域控制的因素进行多因素分析。
单因素分析中，与局部区域控制显著降低相关的因素包括世界卫生组织（WHO）体能状态≥1、AJCC晚期（III期和IV期）、传统放疗分割、总治疗时间≥44天（中位）以及放疗中断。多因素分析中，当单独引入模型时，这三个显著的治疗因素在对强制临床变量进行调整后仍具有显著性。然而，当将这三个治疗因素一起引入模型时，除了AJCC分期（P = 0.017）外，只有放疗中断仍然是一个显著的独立不良预后因素（P = 0.026）。
该多因素分析突出了治疗中断对口咽癌局部区域控制的潜在负面影响。这表明治疗中断可能是一个比放疗方案类型本身更重要的参数。因此，在评估两种放疗方案的相对优点时，为避免对结果的错误解读，必须在多因素模型中纳入其他治疗因素。
