Evaluation of surface and build-up region dose for intensity-modulated radiation therapy in head and neck cancer
Evaluation of surface and build-up region dose for intensity-modulated radiation therapy in head and neck cancer
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DOI：
10.1118/1.1992067
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发表时间：
2005-08-01
期刊：
影响因子：
3.8
通讯作者：
Kim, SY
中科院分区：
文献类型：
--
作者：
Chung, HT;Jin, HS;Kim, SY
尽管取得了很大的进展，但在头颈部癌症的调强放射治疗计划中，表面和积聚区域仍然存在剂量学不确定性。进行实验，以确定在表面和建立区域之间的治疗计划系统（TPS）的预测和实验测量使用辐射变色胶片的剂量学差异。用两块半圆柱形固体水平板制作头颈部压缩膜体模。使用两种商用TPSS（PINNACLE（3）和CORVUS）为两种情况生成治疗计划，一种具有浅目标（类似于0.5 cm深度），另一种具有深目标（类似于6 cm深度）。对54戈伊处方剂量的计划进行了评价。对于每种情况，使用两片辐射变色胶片进行剂量测量。将一小块胶片放置在表面上，另一小块胶片插入体模内。总体而言，两种TPS均显示出与测量结果的良好一致性。对于浅靶病例，在90%的感兴趣区域中，PINNACLE（3）的剂量差异在+/- 300 cGy（相对于规定剂量的5.6%）范围内，CORVUS的剂量差异在240 cGy（4.4%）范围内。对于深部靶病例，在90%的感兴趣区域中，PINNACLE（3）的剂量差异为350（6.5%），CORVUS的剂量差异为+/- 260 cGy（4.8%）。然而，发现对于浅和深目标情况，从表面到深度约0.2 cm存在显著差异。得出的结论是，这两个TPS高估了表面剂量的浅和深目标的情况下。高估量范围为400至1000 cGy（与处方剂量5400 cGy的7.4%至18.5%相似）。(c)2005年美国医学物理学家协会。
Despite much development, there remains dosimetric uncertainty in the surface and build-up regions in intensity-modulated radiation therapy treatment plans for head and neck cancers. Experiments were performed to, determine the dosimetric discrepancies in the surface and build-up region between the treatment planning system (TPS) prediction and experimental measurement using radiochromic film. A head and neck compression film phantom was constructed from two semicylindrical solid water slabs. Treatment plans were generated using two commercial TPSS (PINNACLE(3) and CORVUS) for two cases, one with a shallow (similar to 0.5 cm depth) target and another with a deep (similar to 6 cm depth) target. The plans were evaluated for a 54 Gy prescribed dose. For each case, two pieces of radiochromic film were used for dose measurement. A small piece of film strip was placed on the surface and another was inserted within the phantom. Overall, both TPSs showed good agreement with the measurement. For the shallow target case, the dose differences were within +/- 300 cGy (5.6% with respect to the prescribed dose) for PINNACLE(3) and 240 cGy (4.4%) for CORVUS in 90% of the region of interest. For the deep target case, the dose differences were 350 (6.5%) for PINNACLE(3) and +/- 260 cGy (4.8%) for CORVUS in 90% of the region of interest. However, it was found that there were significant discrepancies from the surface to about 0.2 cm in depth for both the shallow and deep target cases. It was concluded that both TPSs overestimated the surface dose for both shallow and deep target cases. The amount of overestimation ranges from 400 to 1000 cGy (similar to 7.4% to 18.5% with respect to the prescribed dose, 5400 cGy). (c) 2005 American Association of Physicists in Medicine.