Abstract：Objective To explore the intensity of coplanar arc-adjusted radiotherapy with volume-modulated arc therapy (VMAT) and whether the position of the head tilt influences the distribution of radiotherapy dose. Methods From 2015 to 2017,500 patients underwent radiotherapy of the head and kept their head tilted. The simulated non-inclined CT images were obtained by rotating the original CT images. The protocol of the coplanar VMAT whole brain irradiation was 30 Gy and the maximum dose of planning target volume in the hippocampus was limited to 16 Gy. The doses of the optic nerve, optic chiasm and eyeball were lower than 37.5 Gy. The dosimetric parameters of two different protocols were statistically compared by paired t-test. Results The average head tilt angle was (11.12°±0.68°). The homogeneity and the conformal index in the tilted and non-tilted positions were decreased by (8.3±9.6)%(P=0.033) and (5.2±4.1)%(P=0.009). The dose of hippocampus in the tilted position of the head was decreased by (13.6±6.2)% on average compared with that in the non-inclined position (P=0.004). The dose of the lenses was decreased by (15.5±11.1)%(P=0.008) on average. The doses of optic nerve and eyeball were declined by (6.8±5.6)%(P=0.013) and (8.6±6.5)%(P=0.016). Conclusions By tilting the head at an appropriate angle during VMAT whole-brain radiotherapy, the radiation dose distribution of the target volume can be significantly improved and the radiation dose in the hippocampus and visual system can be reduced simultaneously to maintain the therapeutic effect and minimize the effect upon the cognitive and memory function of patients.
Zhou Yang,Qian Yuecheng,Liu Gen. Influence of head position on radiation dose distribution in whole brain volume-modulated arc therapy[J]. Chinese Journal of Radiation Oncology, 2019, 28(9): 692-695.
[1] 汪步海,李颖,刘丽琴,等. 应用海马保护技术预防全脑放疗患者认知功能障碍研究[J]. 中华肿瘤防治杂志,2015,22(18):1470-1474. DOI:10.16073/j.cnki.cjcpt.2015.18.015. Wang BH,Li Y,Liu LQ,et al. Study on prevention of cognitive dysfunction in patients with total brain radiotherapy by hippocampal protective technology[J]. Chin J Cancer Prev Treat,2015,22(18):1470-1474. DOI:10.16073/j.cnki.cjcpt.2015.18.015. [2] 刘桂梅,张新勇,田翠孟,等. 全脑放疗时间对EGFR突变非小细胞肺癌脑转移患者生存的影响[J]. 中国肺癌杂志,2016,19(8):501-507. DOI:10.3779/j.issn.1009-3419.2016.08.03. Liu GM,Zhang XY,Tian CM,et al. Effect of total brain radiotherapy time on the survival of patients with cerebral metastasis of EGFR mutant non-small cell lung cancer[J]. Chin J Lung Cancer,2016,19(8):501-507. DOI:10.3779/j.issn.1009-3419.2016.08.03. [3] 孟鸿飞. 三维适形推量放射治疗配合全脑放射治疗对肺癌脑转移的临床实效性初步评价[J]. 医学研究杂志,2015,44(1):101-104. DOI:10.3969/j.issn.1673-548X.2015.01.029. Meng HF. Preliminary evaluation of the clinical effect of three-dimensional conformal push radiotherapy combined with total brain radiotherapy on brain metastasis of lung cancer[J]. J Med Res,2015,44(1):101-104. DOI:10.3969/j.issn.1673-548X.2015.01.029. [4] Sahgal A,Aoyama H,Kocher M,et al. Phase 3 trials of stereotactic radiosurgery with or without whole-brain radiation therapy for 1 to 4 brain metastases:individual patient data meta-analysis[J]. Int J Radiat Oncol Biol Phys,2015,91(4):710-717. DOI:10.1016/j.ijrobp.2014.10.024. [5] 宁丽华,赵桂芝,张磊,等. 全脑放疗伴随1~4个脑转移瘤同期加量不同调强技术的剂量学研究[J]. 中国医学物理学杂志,2016,33(2):128-133. DOI:10.3969/j.issn.1005-202X.2016.02.005. Ning LH,Zhao GZ,Zhang L,et al. Dosimetry study of different intensity modulation techniques for simultaneous addition of 1~4 brain metastases by total brain radiotherapy[J]. Chin J Med Phys,2016,33(2):128-133. DOI:10.3969/j.issn.1005-202X.2016.02.005. [6] 张春满,郑云峰,米娟. 立体定向放射治疗和全脑放射治疗脑转移瘤对患者神经认知功能和健康相关生活质量的影响分析[J]. 临床和实验医学杂志,2016,15(15):1514-1517. DOI:10.3969/j.issn.1671-4695.2016.15.022. Zhang CM,Zheng YF,Mi J. Effect of stereotactic radiotherapy and total brain radiotherapy on neurological cognitive function and health-related quality of life in patients with brain metastases[J]. J Clin Exper Med,2016,15(15):1514-1517. DOI:10.3969/j.issn.1671-4695.2016.15.022. [7] 杨海燕,孙冰,王军良,等. 全脑放疗中保护海马的调强计划设计[J]. 中国医学物理学杂志,2016,33(3):322-324. DOI:10.3969/j.issn.1005-202X.2016.03.022. Yang HY,Sun B,Wang JL,et al. Strong plan design for protection of hippocampus in total brain radiotherapy[J]. Chin J Med Phys,2016,33(3):322-324. DOI:10.3969/j.issn.1005-202X.2016.03.022. [8] 张倩,胡力宏,宋旭旭,等. 全脑放疗联合γ-刀局部加量治疗脑转移瘤的临床疗效[J]. 医疗卫生装备,2016,37(7):87-89. DOI:10.7687/J. ISSN1003-8868.2016.07.087. Zhang Q,Hu LH,Song XX,et al. Clinical efficacy of total brain radiotherapy combined with gamma-knife local volume therapy for brain metastases[J]. Med Heal Equip,2016,37(7):87-89. DOI:10.7687/J. ISSN1003-8868.2016.07.087. [9] Chabot P,Hsia TC,Ryu JS,et al. Veliparib in combination with whole-brain radiation therapy for patients with brain metastases from non-small cell lung cancer:results of a randomized,global,placebo-controlled study[J]. J Neuro-Oncol,2017,131(1):105-115. DOI:10.1007/s11060-016-2275-x. [10] 曹新桥,王兵,田恒,等. 分次立体定向放疗联合短程全脑放射治疗脑转移瘤的临床疗效观察[J]. 实用临床医药杂志,2017,21(15):163-164. DOI:10.7619/jcmp.201715053. Cao XQ,Wang B,Tian H,et al. Clinical observation of secondary stereotactic radiotherapy combined with short-range total brain radiotherapy for brain metastases[J]. J Pract Clin Med,2017,21(15):163-164. DOI:10.7619/jcmp.201715053. [11] 杨俊,程怀东,王年飞,等. 脑转移瘤全脑放疗后前瞻性记忆与回顾性记忆功能损害的研究[J]. 肿瘤学杂志,2015,21(6):482-486. DOI:10.11735/j.issn.1671-170X.2015.06. B008. Yang J,Cheng HD,Wang NF,et al. Study on prospective memory and retrospective memory impairment after total brain radiotherapy for brain metastases[J]. J Oncol,2015,21(6):482-486. DOI:10.11735/j.issn.1671-170X.2015.06. B008. [12] Wang BH,Hua W,Gu X,et al. Dosimetric study of different radiotherapy planning approaches for hippocampal avoidance whole-brain radiation therapy (HA-WBRT) based on fused CT and MRI imaging[J]. Aust Phys Engineer Sci Med,2015,38(4):767-775. DOI:10.1007/s13246-015-0397-7. [13] 陈峰,姜健飞,蒋利勇. 立体定向放疗与全脑放疗在多发脑转移瘤治疗中的作用分析[J]. 中国医师进修杂志,2015,38(6):397-400. DOI:10.3760/cma.j.issn.1673-4904.2015.06.003. Chen F,Jiang JF,Jiang LY. Analysis of the role of stereotactic radiotherapy and total brain radiotherapy in the treatment of multiple brain metastases[J]. Chin Phys Furt Educat,2015,38(6):397-400. DOI:10.3760/cma.j.issn.1673-4904.2015.06.003. [14] Williams N L,Kim H,Eldredge-Hindy H B,et al. Phase I study of ipilimumab combined with whole-brain radiation therapy or radiosurgery for melanoma patients with brain metastases[J]. Int J Radiat Oncol Biol Phys,2016,96(2):S179-S179. DOI:10.1016/j.ijrobp.2017.05.028. [15] 王聪,张国荣. 脑转移瘤全脑放疗避开海马的可行性研究[J]. 河北医药,2016,38(9):1312-1314. DOI:10.3969/j.issn.1002-7386.2016.09.009. Wang C,Zhang GR. Feasibility study of brain metastatic tumor whole brain radiotherapy avoiding hippocampus[J]. J Hebei Med,2016,38(9):1312-1314. DOI:10.3969/j.issn.1002-7386.2016.09.009. [16] 冯莹莹,张广平,王新帅,等. 全脑放射治疗或联合立体定向放疗对脑转移瘤疗效评价的Meta分析[J]. 循证医学,2016,16(6):355-361. DOI:10.12019/j.issn.1671-5144.2016.06.014. Feng YY,Zhang GP,Wang XS,et al. Meta analysis of efficacy evaluation of brain metastases by total brain radiotherapy or combined stereotactic radiotherapy[J]. Evid-Bas Med,2016,16(6):355-361. DOI:10.12019/j.issn.1671-5144.2016.06.014. [17] 石宇,马剑波,王燕,等. 全脑放疗联合靶向治疗肺腺癌伴脑转移患者的临床疗效[J]. 江苏医药,2017,43(14):1020-1022. DOI:10.19460/j.cnki.0253-3685.2017.14.012. Shi Y,Ma JB,Wang Y,et al. Clinical efficacy of total brain radiotherapy combined with targeted therapy for patients with lung adenocarcinoma associated with brain metastasis[J]. J Jiangsu Med,2017,43(14):1020-1022. DOI:10.19460/j.cnki.0253-3685.2017.14.012. [18] Marsh J C,Godbole R H,Herskovic A M,et al. Sparing of the Neural Stem Cell Compartment During Whole-Brain Radiation Therapy:A Dosimetric Study Using Helical Tomotherapy[J]. Int J Radiat Oncol Biol Phys,2010,78(3):946-954. DOI:10.1111/j.1754-9485.2011.02282.x.
2019, Vol. 28 
