Hodge C Wesley, Tomé Wolfgang A, Weigel Tracy, Traynor Anne M, Mehta Minesh P
Robert Boissoneault Oncology Institute, Ocala, FL 34471, Departments of.
Human Oncology.
J Radiosurg SBRT. 2011;1(3):221-229.
A patient specific nomogram based biological dose selection (NBDS) model may allow for selection of a safe and effective dose schedule to treat early peripheral stage non-small cell lung cancer (NSCLC) with stereotactic body radiotherapy (SBRT). We report the initial clinical outcomes testing these concepts.
23 patients with stage IA/B NSCLC were treated with SBRT. All patients had a prescription isodose volume/residual lung volume ratio of 2-3%, permitting a wide range of dose fractionation schemes under the NBDS-model that should yield a sufficiently low grade 2 or higher pneumonitis rate that the resultant long-term grade 3 or higher complication rate would be <20%. Based on the predications of the patient specific NBDS-model all patients could be safely treated using a modal prescription of 60 Gy in 5 fractions over 10 calendar days, with a median normalized tissue dose (NTD) of 122.4 Gy. Kaplan-Meier analysis was performed to assess local control, overall, cause-specific and disease free survival. Toxicities and response rates were analyzed.
Median follow-up was 43.2 months for all living patients. Analysis of 20 evaluable lesions demonstrated a major response rate of 80%. 3 year actuarial overall, cause-specific, and disease free survival, were 60, 79, and 55%, respectively. 3 year actuarial local control was 89%. Grade 2 or higher acute pulmonary toxicity was observed in 5 patients. The 1, 2 and 3-year actuarial incidence of grade 2 or higher pulmonary toxicity was 15, 27 and 27% (95% CI = 5 48%), with corresponding grade 3 incidence of 4, 10, and 10%. No grade 3 or higher non-pulmonary side-effects were observed.
SBRT using a biological model-based fractionation scheme yields local control and survival rates comparable to other series that treat to higher NTDs; the pulmonary toxicity rate and grades are within the model-predicted parameters, but further follow-up is necessary for long-term validity of the model.
基于患者特异性列线图的生物剂量选择（NBDS）模型或许能够为采用立体定向体部放疗（SBRT）治疗早期外周型非小细胞肺癌（NSCLC）选择安全有效的剂量方案。我们报告了对这些概念进行初步临床验证的结果。
23例IA/B期NSCLC患者接受了SBRT治疗。所有患者的处方等剂量体积/残余肺体积比为2% - 3%，这使得在NBDS模型下可以采用多种剂量分割方案，这些方案应能产生足够低的2级或更高等级肺炎发生率，从而使最终的3级或更高等级并发症发生率低于20%。根据患者特异性NBDS模型的预测，所有患者均可安全地采用在10个日历日内分5次给予60 Gy的模式处方进行治疗，中位归一化组织剂量（NTD）为122.4 Gy。采用Kaplan - Meier分析评估局部控制率、总生存率、病因特异性生存率和无病生存率。分析了毒性反应和缓解率。
所有存活患者的中位随访时间为43.2个月。对20个可评估病灶的分析显示主要缓解率为80%。3年精算总生存率、病因特异性生存率和无病生存率分别为60%、79%和55%。3年精算局部控制率为89%。5例患者出现2级或更高等级的急性肺部毒性。2级或更高等级肺部毒性的1年、2年和3年精算发生率分别为15%、27%和27%（95%CI = 5% - 48%），相应的3级发生率分别为4%、10%和10%。未观察到3级或更高等级的非肺部副作用。
采用基于生物模型的分割方案进行SBRT治疗，其局部控制率和生存率与其他给予更高NTDs的系列研究相当；肺部毒性发生率和等级在模型预测参数范围内，但为验证该模型的长期有效性仍需进一步随访。
