局限期SCLC化放疗后达CR者PCI的IMRT与VMAT海马区保护剂量学研究

doi:10.3760/cma.j.issn.1004-4221.2015.06.017

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Abstract Objective To investigate the dosimetric characteristics of hippocampal-avoidance prophylactic cranial irradiation (HA-PCI) in fixed-field intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) and the feasibility and risks of hippocampal avoidance. Methods
Prophylactic cranial irradiation (PCI) was performed for 16 patients with localized small cell lung cancer (SCLC) who were treated in our hospital from January to August, 2014, and achieved complete response (CR) after chemoradiotherapy, with a prescribed dose of 25 Gy in 10 fractions. CT localization image was fused with brain MRI image to contour the hippocampus on the fused image, and the boundary of the hippocampus was extended 5 mm outward to form the area for reduced dose. IMRT and VMAT plans with hippocampal avoidance were developed separately, and the dose distribution in the whole brain, the hippocampus, and the 5-mm area outside the hippocampus was evaluated for these two plans. Independent-samples t test was applied to evaluate the difference between the two groups. Results The mean hippocampal volume in the 16 patients was 2.76 cm³(range 2.56-3.01 cm³). The mean radiation dose (D_mean) in the hippocampus during IMRT and VMAT was 9.04±0.20 Gy and 10.32±0.28 Gy, respectively, reduced by 66.0% and 61.2%, respectively, compared with the prescribed dose (P=0.55);D_mean in the area for reduced dose during IMRT and VMAT was 13.57±0.90 Gy and 14.86±0.60 Gy, respectively, reduced by 49.0% and 44.1%, respectively, compared with the prescribed dose (P=0.88). Conclusions HA-PCI in IMRT and VMAT meets the clinical requirements, and can reduce the dose in the hippocampus while ensuring the whole-brain radiation dose, and therefore can be applied in PCI and provide a technical support to protect the patient’s neurocognitive function.

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	Zhang Mao
	Sun Tao
	Bu Mingwei
	Guo Xiao
	Zhang Jin

Key words： Lung neoplasms/radiotherapy Radiotherapy,intensity-modulated Radiotherapy, volumetric modulated Prophylactic cranial irradiation Hippocampal avoidance Dosimetry

Corresponding Authors: Zhang Mao,Email:zmflsk@163.com

Cite this article:

Zhang Mao,Sun Tao,Bu Mingwei et al. A dosimetric study of hippocampal-avoidance prophylactic cranial irradiation in intensity-modulated radiotherapy and volumetric modulated arc therapy for patients with localized small cell lung cancer achieving complete response after chemoradiotherapy[J]. Chinese Journal of Radiation Oncology, 2015, 24(6): 675-679.

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http://journal12.magtechjournal.com/Jweb_fszlx/EN/10.3760/cma.j.issn.1004-4221.2015.06.017 OR http://journal12.magtechjournal.com/Jweb_fszlx/EN/Y2015/V24/I6/675

[1] Aupérin A,Arriagada R,Pignon JP,et al Prophylactic cranial irradiation for patients with small cell lung cancer in complete remission [J] N Engl J Med,1999,341(7):476-484.DOI:10.1056/NEJM199908123410703.
[2]Ryan SA,Lowney AC,Murphy M,et al. Prophylactic cranial irradiation:5 years on [J] .BMJ Support Palliat Care,2014,4(1):84-86.DOI:10.1136/bmjspcare-2012－000356.
[3]Peiffer AM,Leyrer CM,Greene-Schloesser DM,et al. Neuroanatomical target theory as a predictive model for radiation-induced cognitive decline [J] .Neurology,2013,80(8):747-753.DOI:10.1212/WNL.0b013e318283bb0a.
[4]Edge SB,Byrd DR,Compton CC,et al. AJCC cancer staging manual [M] .New York:Springer-Verlag,2009:103-105.
[5]Gondi V,Pugh SL,Tome WA,et al. Preservation of memory with conformal avoidance of the hippocampal neural stem-cell compartment during whole-brain radiotherapy for brain metastases (RTOG 0933):a phase Ⅱ multi-institutional trial [J] .J Clin Oncol,2014,32(34):3810-3816.DOI:10.1200/JCO.2014.57.2909.
[6]Monje ML,Mizumatsu S,Fike JR,et al. Irradiation induces neural precursor-cell dysfunction [J] .Nat Med,2002,8(9):955-962.DOI:10.1038/nm749.
[7]Oskan F,Ganswindt U,Schwarz SB,et al. Hippocampus sparing in Whole-brain radiotherapy [J] .Strahlenther Onkol,2014,190(4):337-341.DOI:10.1007/s00066-013-0518-8.
[8]Kazda T,Pospí il P,Dole elová H,et al. Whole brain radiotherapy:consequences for personalized medicine [J] .Rep Pract Oncol Radiother,2013,18(3):133-138.DOI:10.1016/j.rpor.2013.03.002.
[9]Tarnawski R,Michalecki L,Blamek S,et al. Feasibility of reducing the irradiation dose in regions of active neurogenesis for prophylactic cranial irradiation in patients with small-cell lung cancer [J] .Neoplasma,2011,58(6):507-515.DOI:10.4149/neo_2011_06_507.
[10] 李苗苗,王银霞,黄伟,等.小细胞肺癌三种全脑预防性照射计划的剂量学比较 [J] .中华放射医学与防护杂志,2013,33(5):493-496.DOI:10.3760/cma.j.issn.0254-5098.2013.05.009.
[11]Brodin NP,Munck af Rosenschld P,Blomstrand M,et al. Hippocampal sparing radiotherapy for pediatric medulloblastoma:impact of treatment margins and treatment technique [J] .Neuro-Oncol,2014,16(4):594-602.DOI:10.1093/neuonc/not225.
[12]Hsu F,Carolan H,Nichol A,et al. Whole brain radiotherapy with hippocampal avoidance and simultaneous integrated boost for 1－3 brain metastases:a feasibility study using volumetric modulated arc therapy [J] .Int J Radiat Oncol Biol Phys,2010,76(5):1480-1485.DOI:10.1016/j.ijrobp.2009.03.032.
[13]Gondi V,Tolakanahalli R,Mehta MP,et al. Hippocampal-sparing whole-brain radiotherapy:a"how-to" technique using helical tomotherapy and linear accelerator-based intensity-modulated radiotherapy [J] .Int J Radiat Oncol Biol Phys,2010,78(4):1244-1252.DOI:10.1016/j.ijrobp.2010.01.039.
[14]Clivio A,Fogliata A,Franzetti-Pellanda A,et al. Volumetric-modulated arc radiotherapy for carcinomas of the anal canal:a treatment planning comparison with fixed field IMRT [J] .Radiother Oncol,2009,92(1):118-124.DOI:10.1016/j.radonc.2008.12.020.
[15]Truc G,Martin Mirjolet C,et al. The role of whole brain radiotherapy with hippocampal-sparing [J] .Cancer Radiother,2013,17(5－6):419-423.DOI:10.1016/j.canrad.2013.06.042.
[16]Wan JF,Zhang SJ,Wang L,et al. Implications for preserving neural stem cells in whole brain radiotherapy and prophylactic cranial irradiation:a review of 2270 metastases in 488 patients [J] .J Radiat Res,2013,54(2):285-291.DOI:10.1093/jrr/rrs085.
[17]Gondi V,Tome WA,Marsh J,et al. Estimated risk of perihippocampal disease progression after hippocampal avoidance during whole-brain radiotherapy:safety profile for RTOG 0933 [J] .Radiother Oncol,2010,95(3):327-331.DOI:10.1016/j.radonc.2010.02.030.
[18]Harth S,Abo-Madyan Y,Zheng L,et al. Estimation of intracranial failure risk following hippocampal-sparing whole brain radiotherapy [J] .Radiother Oncol,2013,109(1):152-158.DOI:10.1016/j.radonc.2013.09.009.
[19]Withers HR,Suwinski R.Radiation dose response for subclinical metastases [J] .Semin Radiat Oncol,1998,8(3):224-228.DOI:10.1016/S1053-4296(98)80048-9.