Brown Michael W, Ning Holly, Arora Barbara, Albert Paul S, Poggi Matthew, Camphausen Kevin, Citrin Deborah
Radiation Oncology Branch, CCR, National Institutes of Health, Bethesda, MD 20892-1002, USA.
Int J Radiat Oncol Biol Phys. 2006 May 1;65(1):274-83. doi: 10.1016/j.ijrobp.2006.01.003.
To perform an analysis of three-dimensional conformal radiation therapy (3D-CRT), sequential boost intensity-modulated radiation therapy (IMRTs), and integrated boost IMRT (IMRTi) for dose escalation in unresectable pancreatic carcinoma.
Computed tomography images from 15 patients were used. Treatment plans were generated using 3D-CRT, IMRTs, and IMRTi for dose levels of 54, 59.4, and 64.8 Gy. Plans were analyzed for target coverage, doses to liver, kidneys, small bowel, and spinal cord.
Three-dimensional-CRT exceeded tolerance to small bowel in 1 of 15 (6.67%) patients at 54 Gy, and 4 of 15 (26.7%) patients at 59.4 and 64.8 Gy. 3D-CRT exceeded spinal cord tolerance in 1 of 15 patients (6.67%) at 59.4 Gy and liver constraints in 1 of 15 patients (6.67%) at 64.8 Gy; no IMRT plans exceeded tissue tolerance. Both IMRT techniques reduced the percentage of total kidney volume receiving 20 Gy (V20), the percentage of small bowel receiving 45 Gy (V45), and the percentage of liver receiving 35 Gy (V35). IMRTi appeared superior to IMRTs in reducing the total kidney V20 (p < 0.0001), right kidney V20 (p < 0.0001), and small bowel V45 (p = 0.02).
Sequential boost IMRT and IMRTi improved the ability to achieve normal tissue dose goals compared with 3D-CRT. IMRTi allowed dose escalation to 64.8 Gy with acceptable normal tissue doses and superior dosimetry compared with 3D-CRT and IMRTs.
对三维适形放射治疗（3D-CRT）、序贯推量调强放射治疗（IMRTs）和一体化推量调强放射治疗（IMRTi）在不可切除胰腺癌剂量递增中的应用进行分析。
使用15例患者的计算机断层扫描图像。针对54、59.4和64.8 Gy的剂量水平，分别采用3D-CRT、IMRTs和IMRTi生成治疗计划。对计划的靶区覆盖情况、肝脏、肾脏、小肠和脊髓所受剂量进行分析。
在54 Gy时，15例患者中有1例（6.67%）的三维适形放射治疗超出小肠耐受剂量；在59.4 Gy和64.8 Gy时，15例患者中有4例（26.7%）超出小肠耐受剂量。在59.4 Gy时，15例患者中有1例（6.67%）的三维适形放射治疗超出脊髓耐受剂量；在64.8 Gy时，15例患者中有1例（6.67%）超出肝脏剂量限制；调强放射治疗计划均未超出组织耐受剂量。两种调强放射治疗技术均降低了接受20 Gy的总肾体积百分比（V20）、接受45 Gy的小肠体积百分比（V45）以及接受35 Gy的肝脏体积百分比（V35）。在降低总肾V20（p < 0.0001）、右肾V20（p < 0.0001）和小肠V45（p = 0.02）方面，一体化推量调强放射治疗似乎优于序贯推量调强放射治疗。
与三维适形放射治疗相比，序贯推量调强放射治疗和一体化推量调强放射治疗提高了实现正常组织剂量目标的能力。与三维适形放射治疗和序贯推量调强放射治疗相比，一体化推量调强放射治疗能够将剂量递增至64.8 Gy，同时正常组织剂量可接受且剂量学效果更佳。
