Erridge Sara C, Murray Nevin
Departments of Radiation Oncology and Medicine, University of British Columbia, British Columbia Cancer Agency, Vancouver, Canada.
Semin Oncol. 2003 Feb;30(1):26-37. doi: 10.1053/sonc.2003.50017.
Although meta-analysis of randomized trials comparing chemotherapy alone versus chemotherapy plus thoracic irradiation demonstrated that thoracic radiotherapy reduced mortality by 14%, this analysis probably underestimates the effect of optimally delivered thoracic irradiation integrated with appropriate chemotherapy. However, there remains much debate as to the optimal timing of the radiotherapy and the radiotherapy volume, dose, and fractionation. Theoretically, early use of radiotherapy should reduce the probability of chemotherapy and radiation resistance, accelerated repopulation, and metastatic events. Deferred or sequential radiotherapy potentially allows smaller radiotherapy fields. Of the seven randomized controlled trials examining timing, only those with early chemoradiation have 5-year survival rates in excess of 20%. The "chemoradiation package" can be defined as the time from the start of chemotherapy until the completion of radiotherapy. The best median survival and long-term survival rates have been observed in trials with a chemoradiation package time of less than 6 weeks. Protocols combining chemotherapy and radiotherapy must respect radiobiologic principles concerning the time factor derived from radiotherapy fractionation studies.
尽管对单纯化疗与化疗加胸部放疗的随机试验进行的荟萃分析表明，胸部放疗可使死亡率降低14%，但该分析可能低估了与适当化疗相结合的最佳胸部放疗效果。然而，关于放疗的最佳时机以及放疗范围、剂量和分割方式仍存在诸多争议。从理论上讲，早期使用放疗应能降低化疗和放疗抵抗、加速再增殖以及转移事件的发生概率。延迟或序贯放疗可能允许使用较小的放疗野。在七项研究放疗时机的随机对照试验中，只有那些采用早期放化疗的试验5年生存率超过20%。“放化疗套餐”可定义为从化疗开始至放疗结束的时间。在放化疗套餐时间少于6周的试验中观察到了最佳的中位生存期和长期生存率。联合化疗和放疗的方案必须遵循源于放疗分割研究的关于时间因素的放射生物学原则。
