Treatment-Plan Comparison of Three Advanced Radiation Treatment Modalities for Fractionated Stereotactic Radiotherapy to the Head and Neck

• 作者: Adam S. Garden Amol J. Ghia Clifton David Fuller Congjun Wang David I. Rosenthal Dershan Luo Franco De Monte Gary Brandon Gunn He Wang Jack Phan James N. Yang Jay P. Reddy Jing Li Mark S. Chambers Paul D. Brown Samuel Tung Shaan M. Raza Shirley Su Steven J. Frank Xiaodong Zhang Xiaorong Zhu Zhongxiang Zhao
• 来源期刊: 医学物理学、临床工程、放射肿瘤学(英文)
• 学科: 医学
• 关键词: Gamma Knife Extend System STEREOTACTIC RADIOSURGERY Volumetric Modulated Arc THERAPY INTENSITY-MODULATED PROTON THERAPY Spot Scanning PROTON THERAPY
• 年，卷（期）: 2019,（2）
• 页码范围: 106-120
• 页数: 15页
• 分类号: R73

摘要

Purpose: Fractionated stereotactic radiosurgery (FSRS) can be given with at least three modalities: Gamma Knife, with the noninvasive frameless extend system (GKE);linear accelerator-based volumetric modulated arc therapy (VMAT);and intensity-modulated proton therapy (IMPT). We extracted treatment plans for patients who had received FSRS with GKE for recurrent skull base or intracranial tumors, created corresponding plans for VMAT and IMPT, and compared the quality of the three sets of plans. Methods and materials: Plans were extracted for 9 patients with recurrent malignant skull-base tumors (n = 6) or large intracranial tumors (n = 3) who had received FSRS with GKE (median dose 24 Gy in 3 fractions) in 2013 through 2015. Plans for VMAT were generated with a TrueBeam STx LINAC machine using 6-MV photons, and plans for IMPT were generated with multi-field optimization. The optimized VMAT and IMPT plans were normalized to achieve the best possible target coverage while meeting the same dose-volume constraints on organs at risk (OARs) as the GKE plans. Plans were evaluated on the basis of target coverage, conformity index, homogeneity index, gradient index, and treatment efficiency. Results: The median target volume was 10.2 cm3 (range 1.9 - 33.8 cm3). The VMAT and IMPT plans met all OAR constraints, and target coverage and conformity were comparable among all plans. VMAT and IMPT plans showed significantly better target uniformity and treatment delivery efficiency (P P Conclusion: FSRS for skull base and large intracranial lesions delivered by VMAT and IMPT can achieve comparable target coverage, conformity, and sparing of critical structure as the GKE while providing superior target uniformity and treatment delivery efficiency. The GKE had superior high-dose gradients outside the target and thus better protected surrounding normal structures.