非小细胞肺癌三维适形放疗靶区和肺剂量学研究

目的通过剂量学研究明确非小细胞肺癌各照射方法的优劣。方法经病理证实的28例NSCIC患者分为常规放疗和三维适形放疗(3DCRT)计划组。3DCRI、组分为全纵隔预防照射(ANI)、选择性淋巴引流区预防照射(ENI)、不做选择性淋巴引流区预防照射(N—ENI)。通过剂量体积直方图、正常组织并发症概率(NTCP)、肿瘤控制概率(TCP)评价各治疗计划。结果常规放疗、ANI、ENI和N-ENI的TCP分别为0．92、0．97、0．96、0．97；全肺接受≥20Gy照射的百分比(V20)分别为25．2％、28．6％、25．7％、23．1％；NTCP分别为0．06、0．09、0．06、0．04。食管接受≥45Gy照射的百分比(V45)分别为37．5％、48.0％、38．4％、29．7％；NTCP分别为0．08、0．11、0．06、0．05。结论3DCRT在靶区剂量分布上明显优于常规放疗，选择性和不做选择性淋巴引流区预防照射可以更好的保护肺组织和减少放射性食管炎的发生。

Comparison of target volume and lung dosimetric distribution in 3D conformal radiation therapy and conventional radiation for non-small cell lung cancer

Objective To assess the target volume and lung dosimetric dis tributio n in conventional radiation(CR) and 3D conformal radiation therapy (3DCRT) and t o obtain the best treatment for non-small cell lung cancer. Methods For 28 patho logically proven patients,four different methods of planning: conventional radia tion and conformal radiation encompassing all mediastinal nodal irradiation(ANI) ,elective nodal irradiation(ENI) and no nodal irradiation(N-ENI) were used to a s sess the dosimetric distribution of target volume in lung. Dose volume histogram (DVH) ,nomal tissue complication probability(NTCP) and tumor control probability (TCP) were used to assess the target volume dosimetric distribution and lung tis sue complication probability. Results Target volume dosimetric distribution of 3 DCRT were significantly better than conventional radiation. TCP of conventional radiation, ANI, ENI and N-ENI groups were 0.92,0.97,0.96,0.97 respectively; the total lung volume receiving radiation 20?Gy(V 20) were 25.2%,28.6%,25.7%,2 3.1%; NT CP were 0.06,0.09,0.06, 0.04,respectively. The total esophageal volume receiv ing radiation 45?Gy(V 45) were 37.5%,48.0%,38.4%, 29.7%; NTCP were 0.08,0.1 1,0.06,0.05, respectively. Conclusions Target volume dosimetric distribution of 3DCRT is more precise as compared with the conventional radiation. Elective nodal irradiation and no nodal irradiation decrease the lung and esophageal tissue radiation inju ry.