中华医学杂志（英文版）2011，Vol.124Issue(11)：1667-1671,5.DOI:10.3760/CMA.J.ISSN.0366-6999.2011.11.012
Dosimetric comparison between helical tomotherapy and intensity-modulated radiation therapy plans for non-small cell lung cancer
Dosimetric comparison between helical tomotherapy and intensity-modulated radiation therapy plans for non-small cell lung cancer
MENG Ling-ling 1FENG Lin-chun 1WANG Yun-lai 1DAI Xiang-kun 1XIE Chuan-bin1
作者信息
摘要
Abstract
Background Helical tomotherapy (HT) is a new image-guided intensity-modulated radiation therapy (IMRT) technique.It is reported that HT plan for non-small-cell lung cancer (NSCLC) can give better dose uniformity, dose gradients, and protection for the lung than IMRT plan. We compared the dosimetric characteristics of HT for NSCLC with those of conventional IMRT to observe the superiority of HT.Methods There was a comparative case series comprising 10 patients with NSCLC. Computed tomographic (CT) images of delineated targets were transferred to the PrecisePlan planning system (IMRT) and Tomo planning system (HT). The prescription doses were 70 Gy/33F for the gross tumor volume (GTV) and the visible lymph nodes (GTVnd),and 60 Gy/33F for the clinical target volume (CTV) and the clinical target volume of the visible lymph nodes (CTVnd). The dose restrictions for organs at risk were as follows: the maximum dose to spinal cord ≤45 Gy, V20 to the total lungs ＜30%,V50 to the heart ＜50%, and V55 to the esophagus ＜50%. Both plans were evaluated by means of the dose coverage of the targets, dose-volume histograms (DVHs), and other dosimetric indices.Results The dose coverage, conformity, and homogeneity of the targets' volumes were found to be satisfactory in both plans, but the homogeneity of the HT plan was better than that of IMRT. The high-dose radiation volume (V20-V30) to the lung and the mean lung dose (MLD) decreased (P＜0.05), but the low-dose radiation volume (V5-V10) increased slightly in the HT plan (P＞0.05). The maximum doses to the spinal cord, heart, esophagus and trachea in the HT plan were lower than those in the IMRT plan, but the differences were not statistically significant.Conclusions The HT plan provids better dose uniformity, dose gradients, and protectiqn for the organs at risk. It can reduce the high-dose radiation volume for lung and the MLD, but may deliver a larger lung volume of low-dose radiation.关键词
helical tomotherapy/intensity modulated radiotherapy/non-small-cell lung cancer/dosimetryKey words
helical tomotherapy/intensity modulated radiotherapy/non-small-cell lung cancer/dosimetry引用本文复制引用
MENG Ling-ling,FENG Lin-chun,WANG Yun-lai,DAI Xiang-kun,XIE Chuan-bin..Dosimetric comparison between helical tomotherapy and intensity-modulated radiation therapy plans for non-small cell lung cancer[J].中华医学杂志（英文版）,2011,124(11):1667-1671,5.
