Zhang Hao Howard, D'Souza Warren D
Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA.
J Med Phys. 2018 Jan-Mar;43(1):9-15. doi: 10.4103/jmp.JMP_78_17.
PURPOSE/AIM: To describe a two-phase intensity-modulated radiation therapy (IMRT) treatment planning approach, that is, promising for reduction of oral mucositis risk in locally advanced head-and-neck cancer.
Ten locally advanced head-and-neck cancer patients who underwent RT were retrospectively collected. Conventional IMRT and volumetric-modulated arc therapy (VMAT) plans were generated for these patients following clinical protocol. Following the first phase of generating conventional IMRT plans, our approach utilized data from Monte Carlo-based kernel superposition dose calculations corresponding to beam apertures (generated from the conventional IMRT plans) and used an exact mathematical programming-based optimization approach applying linear programming (LP) to dose optimization in the second phase.
Compared with conventional IMRT and VMAT treatment plans, our novel method achieved better preservation of oral cavity (16%-29% lower mean dose, < 0.01), parotid glands (6%-17% lower mean dose, < 0.04), and spinal cord (3-11 Gy lower maximum dose, < 0.03) and lower doses to nonorgan-at-risk/nontarget normal tissues, with the same or better target coverage.
Our LP-based method can be practically implemented in routine clinical use with a goal of limiting radiation-induced oral mucositis for head-and-neck cancer patients.
描述一种两阶段调强放射治疗（IMRT）治疗计划方法，该方法有望降低局部晚期头颈癌患者口腔黏膜炎的风险。
回顾性收集10例接受放疗的局部晚期头颈癌患者。按照临床方案为这些患者制定了传统IMRT和容积调强弧形放疗（VMAT）计划。在生成传统IMRT计划的第一阶段之后，我们的方法利用了基于蒙特卡洛的核叠加剂量计算数据，这些数据对应于射野孔径（由传统IMRT计划生成），并在第二阶段使用基于精确数学规划的优化方法，应用线性规划（LP）进行剂量优化。
与传统IMRT和VMAT治疗计划相比，我们的新方法在相同或更好的靶区覆盖情况下，能更好地保护口腔（平均剂量低16%-29%，P<0.01）、腮腺（平均剂量低6%-17%，P<0.04）和脊髓（最大剂量低3-11 Gy，P<0.03），并降低非危及器官/非靶区正常组织的剂量。
我们基于LP的方法可在常规临床中实际应用，目标是限制头颈癌患者放疗引起的口腔黏膜炎。
