Potential for dose-escalation and reduction of risk in pancreatic cancer using IMRT optimization with lexicographic ordering and gEUD-based cost functions
Potential for dose-escalation and reduction of risk in pancreatic cancer using IMRT optimization with lexicographic ordering and gEUD-based cost functions
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DOI：
10.1118/1.2426403
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发表时间：
2007-02-01
期刊：
影响因子：
3.8
通讯作者：
Ben-Josef, Edgar
中科院分区：
文献类型：
--
作者：
Spalding, Aaron C.;Jee, Kyung-Wook;Ben-Josef, Edgar
胰腺癌的放射治疗受到局部危及器官（OAR）耐受性以及计划靶体积（PTV）和OAR体积频繁重叠的限制。使用字典排序（LO），一种分层优化技术，广义等效均匀剂量（gEUD）成本函数，我们研究了调强放射治疗（IMRT）增加胰腺肿瘤和血管受累区域剂量的潜力，这些区域排除了手术切除[手术增强量（SBV）]。我们比较了15例局部晚期不可切除胰腺癌的三维适形（3DCRT）和调强放射治疗计划。我们创建了使用LO优化的IMRT计划，其中基于gEUD的成本函数考虑了所产生的不均匀剂量分布的每个部分的贡献。与3DCRT相比，LO-IMRT计划允许显著的PTV剂量增加;中位数从52戈伊增加到66戈伊（a=-5，p < 0.005），中位数从50戈伊增加到59戈伊（a=-15，p < 0.005）。LO-IMRT还允许SBV增加至85戈伊，无论数值如何，沿着OAR的剂量显著降低。我们的结论是，与传统的3DCRT相比，具有gEUD成本函数的LO-IMRT可以允许胰腺肿瘤的剂量递增，同时降低危及器官的剂量。(c)2007年美国医学物理学家协会。
Radiotherapy for pancreatic cancer is limited by the tolerance of local organs at risk (OARs) and frequent overlap of the planning target volume (PTV) and OAR volumes. Using lexicographic ordering (LO), a hierarchical optimization technique, with generalized equivalent uniform dose (gEUD) cost functions, we studied the potential of intensity modulated radiation therapy (IMRT) to increase the dose to pancreatic tumors and to areas of vascular involvement that preclude surgical resection [surgical boost volume (SBV)]. We compared 15 forward planned three-dimensional conformal (3DCRT) and IMRT treatment plans for locally advanced unresectable pancreatic cancer. We created IMRT plans optimized using LO with gEUD-based cost functions that account for the contribution of each part of the resulting inhomogeneous dose distribution. LO-IMRT plans allowed substantial PTV dose escalation compared with 3DCRT; median increase from 52 Gy to 66 Gy (a=-5,p < 0.005) and median increase from 50 Gy to 59 Gy (a=-15,p < 0.005). LO-IMRT also allowed increases to 85 Gy in the SBV, regardless of a value, along with significant dose reductions in OARs. We conclude that LO-IMRT with gEUD cost functions could allow dose escalation in pancreas tumors with concomitant reduction in doses to organs at risk as compared with traditional 3DCRT. (c) 2007 American Association of Physicists in Medicine.