Investigation on the physical dose filtered by linear energy transfer for treatment plan evaluation in carbon ion therapy

Author:

Schafasand Mansure12,Resch Andreas Franz1,Nachankar Ankita13,Gora Joanna1,Traneus Erik4,Glimelius Lars4,Georg Dietmar12,Stock Markus15,Carlino Antonio1,Fossati Piero15

Affiliation:

1. MedAustron Ion Therapy Center Wiener Neustadt Austria

2. Department of Radiation Oncology Medical University of Vienna Vienna Austria

3. ACMIT Gmbh Wiener Neustadt Austria

4. RaySearch Laboratories AB Stockholm Sweden

5. Department of Oncology Karl Landsteiner University of Health Sciences Krems an der Donau Austria

Abstract

AbstractBackgroundLarge tumor size has been reported as a predicting factor for inferior clinical outcome in carbon ion radiotherapy (CIRT). Besides the clinical factors accompanied with such tumors, larger tumors receive typically more low linear energy transfer (LET) contributions than small ones which may be the underlying physical cause. Although dose averaged LET is often used as a single parameter descriptor to quantify the beam quality, there is no evidence that this parameter is the optimal clinical predictor for the complex mixed radiation fields in CIRT.PurposePurpose of this study was to investigate on a novel dosimetric quantity, namely high‐LET‐dose (, the physical dose filtered based on an LET threshold) as a single parameter estimator to differentiate between carbon ion treatment plans (cTP) with a small and large tumor volume.MethodsTen cTPs with a planning target volume, (large) and nine with a (small) were selected for this study. To find a reasonable LET threshold () that results in a significant difference in terms of , the voxel based normalized high‐LET‐dose () distribution in the clinical target volume (CTV) was studied on a subset (12 out of 19 cTPs) for 18 LET thresholds, using standard distribution descriptors (mean, variance and skewness).The classical dose volume histogram concept was used to evaluate the and distributions within the target of all 19 cTPs at the before determined . Statistical significance of the difference between the two groups in terms of mean and volume histogram parameters was evaluated by means of (two‐sided) t‐test or Mann‐Whitney‐U‐test. In addition, the minimum target coverage at the above determined was compared and validated against three other thresholds to verify its potential in differentiation between small and large volume tumors.ResultsAn of approximately was found to be a reasonable threshold to classify the two groups. At this threshold, the and were significantly larger () in small CTVs. For the small tumor group, the near‐minimum and median (and ) in the CTV were in average (0.31 ± 0.08) and (0.46 ± 0.06), respectively. For the large tumors, these parameters were (0.20 ± 0.01) and (0.28 ± 0.02). The difference between the two groups in terms of mean near‐minimum and median () was 2.7 Gy (11%) and 5.0 Gy (18%), respectively.ConclusionsThe feasibility of high‐LET‐dose based evaluation was shown in this study where a lower was found in cTPs with a large tumor size. Further investigation is needed to draw clinical conclusions. The proposed methodology in this work can be utilized for future high‐LET‐dose based studies.

Publisher

Wiley

Subject

General Medicine

Reference32 articles.

1. ICRU Report 85: Fundamental quantities and units for ionizing radiation;JICRU,2011

2. Carbon Ion Radiobiology

3. ICRU Report 78: Prescribing, Recording, and Reporting Proton‐Beam Therapy;JICRU,2007

4. Report of the AAPM TG-256 on the relative biological effectiveness of proton beams in radiation therapy

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3