三维适形加量放射治疗非小细胞肺癌32例分析

目的探讨三维适形加量放射治疗非小细胞肺癌（NSCLC）的优势。方法32例中央型非小细胞肺癌，cT模拟机定位，输入TPS（Pinnacle37．4／7．6），勾画GTV1，先行三维适形放疗36Gy／18F～40Gy／20F，第2次CT定位，勾画GTV2，继续给予三维适形放射治疗至66Gy／33F～70Gy／35F。全程均按CTVl设置靶区，为Plan1，为初始计划，为虚拟计划；而前半程按CTV1，后半程按CTV2制定治疗计划为Plan3，为实际执行计划。结果NSCLC放射治疗中肿瘤退缩比例为12．3％～57．8％，平均比例37．1％，大于40％的有13例（40．6％），t=2．96，P〈0．05。CR6例（18．8％），PR23例（71．9％），NC3例（9．4％）。1年生存率84．4％（27／32），死亡5例（15．6％）。远处转移9例（28．1％）。早期放射性肺损伤1级19例（59．4％），2级9例（28．1％），3级3例（9．4％）。放射性食管炎：1级22例（68．8％），2级10例（31．2％）。后期放射肺纤维化：0级3例（9．4％），1级24例（75％），2级5例（15．6％）。结论三维适形加量放射治疗NSCLC过程中，GTV存在明显退缩，再次重新勾画GTV并加量，但对PVV未产生明显影响，但根据退缩后肿瘤重新勾画靶区使心脏接受剂量的降低具有统计学意义，对肺V20和MLD剂量降低接近统计学意义。

An analysis of dose-escalation study using three-dimensional conformal radiotherapy in 32 cases with non-small cell lung cancinoma

Objective To investigate tumor shrinkage during 3D conformal radiotherapy for non-small cell lung cancer, and to reduce treatment - volume and obtain a better technique in the treatment of lung cancers. Methods 32 patients with Ⅱ A- Ⅲ B non-small cell central lung cancer were chosen in the present study. CT simulation location and Pinnacle37 · 4/7 · 6 treatment planning system were used. First, defining GTVI , three-dimensional conformal radiation was used until tumor dose reached 36 Gy/18 f - 40 Gy/20 f. Second, by repeating the planning CT scan during the final week of the treatment, defining GTV2 three-dimensional conformal radiation therapy was used until the total radiation dose was 66 Gy/33 f -70 Gy/35f. Plan 1 was the plan where CTV1 was the target. This plan was the initial one, and a virtual one; whereas in plan 3 the front part used CTV1 as target, and the later part used CTV2 as target, the actual executive plan. Results The mean population of tumor shrinkage during 3 D conformal radiotherapy for non - small cell lung cancer was 37. 1%, and 13 patients 〉40%. The short-term treatment resulted in complete response （CR） rate of 18.8% , partial response （PR） rate of 71.9%, NC 9. 4%, and overall response （ CR ＋ PR） rate of 90. 6%. 1 -year survival rate was 84. 4%. Acute radiation pneumonitis were mostly RTOG grade 1,9 （ 28. 1% ） patients had grade 2, 3 （ 9.4% ） patients had grade 3. Acute radiation esophaitis occurred in 68.8% （22） of patients with grade 1 and 31.2% （10） with grade 2. Late radiation pulmonary RTOG fibrosis were mostly grade 1 （75%）, 3 （9.4%） patients had grade 0, 5 （ 15.6% ） patients had grade 2. Conclusion During the treatment of 3D conformal radiotherapy, there is significant volume reduction, and re-outline the target margin is necessary. But PTV is not influenced significantly. There is significantly heart dose reduction,and for pulmonary V20 and V30 the significance is toward 0. 05.