三维适形与调强放疗技术在胃癌术后放疗中的剂量学比较  

Comparison of dosimetry between three-dimension conformal and intensity modulated plan in postoperative radiotherapy for gastric cancer

作　　者：胡伟刚[1] 章真[1] 徐志勇[1] 顾卫列[2] 陆惠忠[1] 何少琴[1] 

机构地区：[1]复旦大学附属肿瘤医院放疗科,上海200032 [2]复旦大学附属肿瘤医院腹部外科,上海200032

出　　处：《中华放射肿瘤学杂志》2007年第4期273-276,共4页Chinese Journal of Radiation Oncology

摘　　要：目的比较胃癌放疗中三维适形放疗(3DCRT)和调强放疗(IMRT)技术的剂量学差异,为临床应用提供参考。方法采用3DCRT治疗的5例胃癌术后患者,放疗时使用了主动呼吸门控技术,以减少呼吸引起的器官运动。IMRT计划采用7个共面等间距野,仅用于剂量学比较。患者靶区设定的处方剂量为至少95%计划靶体积(PTV)接受45.00 Gy,至少99%PTV接受42.75 Gy。根据积分剂量体积直方图(DVH)比较PTV受量和相关正常器官的受量差异和剂量分布。结果与IMRT相比3DCRT的剂量均匀性和适形度略差,但两者在PTV受量上剂量相似。对左、右肾受15 Gy剂量的体积百分比(V_(15))而言,3DCRT好于IMRT;从正常肝的平均受量及V_(30)上看,IMRT稍优于优势;在脊髓的受量上两者相似。结论3DCRT技术在主动呼吸门控辅助下,PTV和部分正常器官的受量上可接近或者达到采用相等野数的IMRT的结果。Objective To compare the dose distribution and volume histogram（ DVH ） of three-dimension conformal radiation therapy（3DCRT）and intensity modulated radiation therapy（IMRT） of the planning target volume（PTV） and critical organs in gastric cancer treatment planning. Methods Five patients who had gastric cancer treated with postoperative radiation in Cancer Hospital, Fudan University from February to April 2006 were selected. All patients were treated by 3DCRT with Active Breathing Control （ABC） technique to minimize the organ movements due to patient＇s respiration. 7-coplanar-fields IMRT plans were designed retrospectively for dosimetric comparison. The dose prescription was 45.00 Gy to 95 % of PTV and 42.75 Gy to 99% of PTV. The cumulated DVHs and 3D dose distributions of 3DCRT and IMRT plans were compared. Results IMRT and 3DCRT had comparable PTV coverage of the prescribed dose, however, the IMRT plans showed better dose uniformity and conformity. For the normal liver, V30 and mean dose of IMRT plans were lower. However, the dose to the liver with 3DCRT was still within the clinical tolerance. 3DCRT plans showed lower dose of the kidneys （ VI5 ）. IMRT and 3DCRT plans had comparable maximum dose to the spinal cord. Conclusions In this preliminary study, 3DCRT split-field plans for patients treated with ABC technique shows comparable dose coverage in PTV with 7 coplanar fields IMRT plans. However, IMRT had slightly lower dose to the liver and may be potentially benefitial to patients with liver dysfunction.

关 键 词：胃肿瘤/放射疗法 三维适形放疗 调强放疗 剂量学 

分 类 号：R735.2[医药卫生—肿瘤]