Background and objective: It has been known that stereotactic radiotherapy has been widely used in clinical practice. The aim of this study is to evaluate the feasibility to treat small lung neoplasms with hypofraction stereotactic radiotherapy.
Methods: From September 2005 to November 2009, 15 patients with non-small cell lung cancer and solitary metastatic lung cancer were treated with hypofraction stereotactic radiotherapy. Dose volume histogram was used to evaluated treatment plans. Lesion diameter 1.5 cm-4.0 cm. Toxicity was evaluated with the NCI-CTCAE 3.0 version. A dose 48 Gy-50 Gy was given in 4-10 fractions.
Results: The short-term results showed that the complete response (CR) rate, the partial response (PR) rate, the overall response (CR+PR) rate, the one-year local control rate, the one-year survival rate was 60%, 20%, 80%, 100% and 86.67% respectively. Two patients had radiation pneumonitis of 0 grade. Acute radiation pneumonitis of grade I occurred in 9 patients, 4 patients had radiation pneumonitis of grade II and no patient developed serious (grade III) radiation pneumonitis.
Conclusions: The hypofraction stereotactic radiotherapy is safe for small lung neoplasms.
背景与目的: 立体定向放疗在临床应用中取得了令人振奋的成果。本研究旨在评价直线加速器大分割立体定向放疗治疗肺部小肿瘤的可行性。
方法: 纳入2005年9月-2009年8月本院收治的15例符合要求的非小细胞肺癌（non-small cell lung cancer, NSCLC）及肺部转移瘤患者。放疗前在模拟机下测定肺部病灶的左右、前后、头尾三个方向的呼吸运动幅度，采用CT模拟定位，选择三维适形立体定向放疗。放疗剂量如下：5 Gy×10次/12天生物有效剂量[（biological effective dose, BED）=75 Gy]2例，6 Gy×8次/10天（BED=76.8 Gy）3例，8 Gy×6次/8天（BED=86.4 Gy）2例，12 Gy×4次/4天（BED=132 Gy）8例，病变直径1.5 cm-4 cm，毒性评价标准按照NCI-CTCAE 3.0版本进行。
结果: 15例患者患者近期疗效完全缓解（complete response, CR）率为60%，部分缓解（partial response, PR）率为20%，总有效率（CR+PR）为80%。1年局部控制率为100%，1年生存率为86.67%。肺的早期放射性反应0级2例，Ⅰ级9例，Ⅱ级4例，无Ⅲ级以上的副反应。
结论: 利用直线加速器对肺部小病灶实施48 Gy/4次/4天的照射是可行的。