Su Sheng-fa, Han Fei, Zhao Chong, Chen Chun-yan, Xiao Wei-wei, Li Jia-xin, Lu Tai-xiang
Department of Radiation Oncology, Sun Yat-Sen University Cancer Center; State Key Laboratory of Oncology in South China Guangzhou, Guangzhou 510060, China.
Zhonghua Yi Xue Za Zhi. 2011 Feb 22;91(7):469-72.
At present, the clinical data about the effect of overall treatment time (OTT) on local control for nasopharyngeal carcinomas (NPC) patients mainly derived from conventional radiotherapy (CRT). The effect of OTT on local control for NPC patients treated with IMRT is still unclear. This study was to explore the effect of OTT on local control in IMRT for NPC patients.
Clinical data of 850 NPC (T1-4N0-3M0) patients that had undergone radical radiotherapy with IMRT from May 2001 to January 2008 in Sun Yat-sen University Cancer Center were analyzed retrospectively. All patients were divided into two groups, which were group with OTT ≤ 42 and group with OTT > 42 days respectively. Survival was calculated using the Kaplan-Meier method. The log-rank test was used to compare survival curves. The effect of clinical factors and treatment related factors on LCR were studied with univariate and multivariate analyses using logistic regression.
The 5-years local recurrence-free survival (LRFS) rate of group with OTT ≤ 42 were 90.7%, and 90.9% in group with OTT > 42, no significant differences were found between these two groups (χ² = 0.028, P = 0.866). Further stratified analysis found that the LRFS rate for early T-stage patients was no significant difference between group with OTT ≤ 42 and group with > 42 days, they were 97.2% and 97.9% (χ² = 0.672, P = 0.412). For advanced T-stage patients, the LRFS rate of OTT ≤ 42 and > 42 days were 86.5% and 87.2% respectively (χ² = 0.151, P = 0.698). The 5-year LRFS rate were 94.4% vs 93.0% (χ² = 0.090, P = 0.764) at OTT > 42 vs ≤ 42 days for patients treated with IMRT alone, and 89.7% vs 87.6% (χ² = 0.060, P = 0.807) for patients in combination chemotherapy with IMRT. We divided all patients into three groups: OTT ≤ 42 d, 43 - 49 d and ≥ 50 d, the 5-years LRFS rate of the three group was 90.7%, 91.7% and 88.4%, respectively, there was no significant difference of LRFS among those three groups (χ² = 0.136, P = 0.934). Univariate analysis showed that T-stage and GTV volume were correlation with local control. In multivariate analysis, GTV volume was confirmed as independent prognostic factors for local control.
Within the range of the OTT observed in our study, prolonged OTT did not have adverse effect on local control. GTV volume was independent prognostic factors in local control for NPC patients treated with IMRT.
目前，关于总治疗时间（OTT）对鼻咽癌（NPC）患者局部控制效果的临床数据主要来源于传统放疗（CRT）。OTT对接受调强放疗（IMRT）的NPC患者局部控制的影响仍不明确。本研究旨在探讨OTT对接受IMRT的NPC患者局部控制的影响。
回顾性分析2001年5月至2008年1月在中山大学肿瘤防治中心接受IMRT根治性放疗的850例NPC（T1-4N0-3M0）患者的临床资料。所有患者分为两组，分别为OTT≤42天组和OTT>42天组。采用Kaplan-Meier法计算生存率。采用对数秩检验比较生存曲线。采用逻辑回归单因素和多因素分析研究临床因素和治疗相关因素对局部控制率（LCR）的影响。
OTT≤42天组的5年局部无复发生存率（LRFS）为90.7%，OTT>42天组为90.9%，两组间差异无统计学意义（χ²=0.028，P=0.866）。进一步分层分析发现，早期T分期患者中，OTT≤42天组和>42天组的LRFS率差异无统计学意义，分别为97.2%和97.9%（χ²=0.672，P=0.412）。对于晚期T分期患者，OTT≤42天组和>42天组的LRFS率分别为86.5%和87.2%（χ²=0.151，P=0.698）。单纯接受IMRT治疗的患者，OTT>42天组与≤42天组的5年LRFS率分别为94.4%和93.0%（χ²=0.090，P=0.764）；接受IMRT联合化疗的患者，5年LRFS率分别为89.7%和87.6%（χ²=0.060，P=0.807）。将所有患者分为三组：OTT≤42天、43-49天和≥50天，三组的5年LRFS率分别为90.7%、91.7%和88.4%，三组间LRFS差异无统计学意义（χ²=0.136，P=0.934）。单因素分析显示，T分期和大体肿瘤体积（GTV）与局部控制相关。多因素分析中，GTV被确认为局部控制的独立预后因素。
在本研究观察的OTT范围内，延长OTT对局部控制无不良影响。GTV是接受IMRT治疗的NPC患者局部控制的独立预后因素。
