利用Cone-Beam CT探讨支抗微螺钉周围骨密度与其稳定性的关系

目的:利用Cone-Beam CT测量支抗微螺钉周围骨密度值,探讨其与微螺钉稳定性的关系。方法:选取颌骨左右对称植入微螺钉后一侧松动而另一侧稳固的7名(共18枚微螺钉)正畸患者。拍摄CBCT,所得三维影像重建后用OnDemand 3DApplication软件对微螺钉骨内部分周围2mm范围内骨密度(以Hounsfield Unit表示)进行测量,自身对照比较分析双侧对称部位所植入微螺钉周围骨密度测量值间的差异。结果:松动微螺钉与稳定微螺钉骨内部分周围2mm范围内骨密度无统计学差异,两侧微螺钉钉尖部1/3、钉中部1/3及钉颈部1/3周围骨密度均无统计学差异。结论:微螺钉种植支抗的稳定性与其周围骨密度间未发现明显相关性。

基于Cone Beam CT图像的呼吸运动分析

呼吸运动是有一定规律性的运动,传统呼吸运动模型用公式描述,不能准确反映不同病人的特点或同一病人不同时期的特点,无法满足实时准确分析的需要。为此,我们提出了一种通过跟踪病人自由呼吸状态下所采集的Cone Beam CT图像序列中的横隔膜的运动来建立病人呼吸运动模型的方法。该方法建立的模型与传统的呼吸运动理论模型非常相似,证明了它是可行且有效的,同时该方法更能实时准确地反映病人的呼吸运动规律,具有很高的临床实用价值。

Detail-preserving ring artifact correction method for cone-beam CT

Ring artifact is the major factor that seriously influence quality of computed tomography(CT)image reconstruction,especially in testing large-scale workpieces.To remove ring artifact quickly and efficiently,a kind of ring artifact correction method is improved based on the post-processing CT image reconstruction in this paper.At first,transform the CT image from the rectangular coordinates into polar coordinates.Next,design multidimensional filter to filter the image and calculate the mean and variance of each filtered pixel in polar coordinates.The location of artifact point is determined by the double precision.One is the comparison of calculated variance and variance threshold,and another is the comparison of pixel value and pixel value threshold.Then,process the artifact points in a reasonable manner and do details remain to CT image in particular.At last,convert corrected polar image into rectangular coordinates.The actual experiment shows that compared with the original method,improved method can better correct the ring artifacts and keep the image details for CT images.It is a kind of practical ring artifact correction methods for subsequent processing and quantitative analysis.

The Association between Lower Incisal Inclination and Morphology of the Supporting Alveolar Bone—A Cone-Beam CT Study

Aim To investigate the relationship between the positioning of the lower central incisor and physical morphology of the surrounding alveolar bone. Methodology Thirty-eight patients （18 males, 20 females）, with mean age of 13.4 years, were included in this study. As part of orthodontic treatment planning the patients were required to take dental Cone-beam CT （CBCT） covering the region of lower incisors, the sur- rounding alveolar bone and the mandibular symphysis. The cephalometric parameters were designed and measured to indicate the inclination of lower central incisor and physical morphology of the adjacent alveolar bone. Computer-aided descriptive statistical analysis was performed using SPSS 15.0 software package for Windows. A correlation analysis and a linear regression analysis between the incisor inclination and the alveolar bone morphology were performed. Results Significant positive correlations were found between the lower central incisor inclination and the morphological contour of the alveolar bone （P〈0.05）. The lower central incisor root apex was closer to the lingual alveolar crest when it was buccally inclined. Conclusion The morphology of the alveolar bone may be affected by incisal inclination.

Slice-wise reconstruction for low-dose cone-beam CT using a deep residual convolutional neural network

Because of the growing concern over the radiation dose delivered to patients, X-ray cone-beam CT(CBCT) imaging of low dose is of great interest. It is difficult for traditional reconstruction methods such as Feldkamp to reduce noise and keep resolution at low doses. A typical method to solve this problem is using optimizationbased methods with careful modeling of physics and additional constraints. However, it is computationally expensive and very time-consuming to reach an optimal solution. Recently, some pioneering work applying deep neural networks had some success in characterizing and removing artifacts from a low-dose data set. In this study,we incorporate imaging physics for a cone-beam CT into a residual convolutional neural network and propose a new end-to-end deep learning-based method for slice-wise reconstruction. By transferring 3D projection to a 2D problem with a noise reduction property, we can not only obtain reconstructions of high image quality, but also lower the computational complexity. The proposed network is composed of three serially connected sub-networks: a cone-to-fan transformation sub-network, a 2D analytical inversion sub-network, and an image refinement sub-network. This provides a comprehensive solution for end-to-end reconstruction for CBCT. The advantages of our method are that the network can simplify a 3D reconstruction problem to a 2D slice-wise reconstruction problem and can complete reconstruction in an end-to-end manner with the system matrix integrated into the network design. Furthermore, reconstruction can be less computationally expensive and easily parallelizable compared with iterative reconstruction methods.

Analytical Calculation of the Compton Single Scatter Component of Pencil Beam Scatter Kernel for Scatter Correction in kV Cone Beam CT (kV-CBCT)

The accuracy of conventional superposition or convolution methods for scatter correction in kV-CBCT is usually compromised by the spatial variation of pencil-beam scatter kernel (PBSK) due to finite size, irregular external contour and heterogeneity of the imaged object. This study aims to propose an analytical method to quantify the Compton single scatter (CSS) component of the PBSK, which dominates the spatial distribution of total scatter assuming that multiple scatter can be estimated as a constant background and Rayleigh scatter is the secondary source of scatter. The CSS component of PBSK is the line integration of scatter production by incident primary photons along the beam line followed by the post-scattering attenuation as the scattered photons traverse the object. We propose to separate the object-specific attenuation term from the line integration and equivalently replace it with an average value such that the line integration of scatter production is object independent but only beam specific. We derived a quartic function formula as an approximate solution to the spatial distribution of the unattenuated CSS component of PBSK. The “effective scattering center” is introduced to calculate the average attenuation. The proposed analytical framework to calculate the CSS was evaluated using parameter settings of the On-Board Imager kV-CBCT system and was found to be in high agreement with the reference results. The proposed method shows highly increased computational efficiency compared to conventional analytical calculation methods based on point scattering model. It is also potentially useful for correcting the spatial variant PBSK in adaptive superposition method.

Clinical Significance of Pathological and Anatomical Findings in Cone Beam CT Scans of the Maxillary Sinus

Objective: To determine the range and prevalence of pathological conditions and demonstration of significant anatomical structures in the maxillary sinuses using the cone beam computerized tomographic (CBCT) scan. Methodology: Case series of 60 CBCT scans of the maxillae. Results: Forty (67%) of the scans were of female patients while the rest (20, 33%) were of males. Remarkably, the majority of the scans were requested for those patients who sought dental implant fabrication. Overall, 35 (58%) scans demonstrated pathological features while 8 (13%) demonstrated significant anatomical structures. Pathological features included mucosal thickening in 26 (43%), polypoid lesions in 9 (15%), total antral opacification in 1 (2%) and foreign body in 1 (2%). The commonest anatomic feature was dental root protrusion into the maxillary sinuses in 8 (13%). Conclusion: The CBCT imaging is an important tool for investigating the maxillary sinuses for pathology and the demonstration of the associated anatomic relations.

锥形术CT测量分析下颌第一磨牙拟种植区剩余牙槽嵴的骨量

背景:随着口腔领域的发展与进步,口腔种植技术逐渐成为替代传统义齿的主流选择。近年来,多种骨增量技术的成熟以及口腔数字化领域的不断发展,使种植适应证不断扩大,种植手术的成功率也越来越高。但是种植手术前使用锥形术CT对剩余牙槽嵴骨量进行准确测量并且个性化制定合适的种植方案,成为一部分临床医师的难题。目的:采用锥形束CT对下颌第一磨牙拟种植区剩余牙槽嵴骨量进行测量分析,为优化下颌第一磨牙区种植方案的设计提供参考。方法:采用回顾性研究设计,纳入205例下颌第一磨牙缺失患者的锥形术CT影像,测量下颌第一磨牙拟种植区剩余牙槽嵴高度及宽度,并将剩余牙槽嵴形态分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4类(Ⅱ、Ⅲ、Ⅳ类剩余牙槽嵴为骨量不足),统计分析下颌第一磨牙剩余牙槽嵴高度、宽度、形态频数分布,不同性别患者下颌第一磨牙剩余牙槽嵴高度和牙槽嵴顶宽度的差异,剩余牙槽嵴高度与剩余牙槽嵴顶宽度、剩余牙槽嵴底宽度的相关性,年龄与剩余牙槽嵴顶宽度、高度的相关性。结果与结论:①下颌第一磨牙拟种植区剩余牙槽嵴高度平均为(12.14±2.96)mm,其中<12 mm者占43.41%(89/205),下颌第一磨牙拟种植区牙槽嵴顶宽度平均为(6.80±1.65)mm,其中<6 mm者占26.34%(54/205);②男性下颌第一磨牙剩余牙槽嵴高度高于女性,但差异无显著性意义(P>0.05),男性下颌第一磨牙剩余牙槽嵴顶宽度宽于女性,差异有显著性意义(P<0.01);③剩余牙槽嵴高度与剩余牙槽嵴顶宽度和剩余牙槽嵴底宽度呈负相关(P<0.05);年龄与剩余牙槽嵴顶宽度呈正相关(P<0.05),与剩余牙槽嵴高度无明显相关性(P>0.05);④剩余牙槽嵴形态Ⅰ类占58.05%(119/205),Ⅱ类占9.27%(19/205),Ⅲ类占20.49%(42/205),Ⅳ类占12.19%(25/205),其中多数为Ⅲ类剩余牙槽嵴骨量不足,临床医生需要根据剩余牙槽嵴类型个性化设计最佳的种植方案。

Cone Beam CT在牙种植术中应用的临床观察

文章通过对64例拟行牙种植术患者进行Cone Beam CT检查,观察CT影像在牙种植手术适应证评价与手术设计中的作用。与X线曲面断层片及模型观测结果相比,Cone Beam CT影像提供了更直观、更精确的种植区骨条件信息,提高了牙种植手术的效率,牙种植手术无1例失败。Cone Beam CT应用于牙种植术,能够使手术更加安全、高效,具有较高的临床应用价值。

Tissue Density Mapping of Cone Beam CT Images for Accurate Dose Calculations

Purpose: To improve the accuracy in megavoltage photon beam dose calculation in CBCT-based radiation treatment (RT) plans, using a kilovoltage cone-beam computed tomography (CBCT)-to-density-step (CBCT-SF) function. Materials and Methods: The CBCT-SF table is constructed from differential histograms of the voxel values of CBCT and Fan-beam CT (FBCT). From the CBCT histograms, frequency peaks representing air, lung, soft tissue and bone are observed and their widths in CT numbers are assigned to the lower and higher bounds of the steps in the CBCT-SF. The CBCT-SF is entered into a planning system as an alternative to the clinical CT-to-density table. The CT image sets studied in this work consist of FBCT and CBCT scans of three patients: a prostate cancer patient, a lung cancer patient and a head and neck patient;and of a humanoid phantom at sections of the pelvis, the thorax and the head. Deformable image registration is used to map the patient FBCT scans to the corresponding CBCT images to minimize anatomical variations. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) plans are made on the FBCT image sets of the patients and the phantom. The plans are recalculated on the CBCT scans using both the conventional CT-to-density table and the CBCT-SF. Dose calculations on the CBCT images and FBCT images are compared using dose differences, distance to agreement (DTA), Gamma analyses and dose volume histogram (DVH) analyses. Results: The results show that IMRT plans optimized using CBCT scans and FBCT scans agree dosimetrically within 1% when the CBCT-SF is used for the CBCT-based plans, including thoracic IMRT plan. In contrast, up to 5% dose difference is observed between IMRT plans optimized on FBCT scans and CBCT scans for thoracic cases if conventional CT-to-density table is used on CBCT images. Conclusions: The simple stepwise mapping of the CBCT numbers to density using the CBCT-SF resolves the inaccuracies in dose calculations previously reported in CBCT-based RT plans. CBCT-SF can be used in Image-Guided adaptive radiotherapy planning.

Image quality of cone beam CT on respiratory motion

In this study,the influence of respiratory motion on Cone Beam CT (CBCT) image quality was investigated by a motion simulating platform,an image quality phantom,and a kV X-ray CBCT.A total of 21 motion states in the superior-inferior direction and the anterior-posterior direction,separately or together,was simulated by considering different respiration amplitudes,periods and hysteresis.The influence of motion on CBCT image quality was evaluated with the quality indexes of low contrast visibility,geometric accuracy,spatial resolution and uniformity of CT values.The results showed that the quality indexes were affected by the motion more prominently in AP direction than in SI direction,and the image quality was affected by the respiration amplitude more prominently than the respiration period and the hysteresis.The CBCT image quality and its characteristics influenced by the respiration motion,and may be exploited in finding solutions.

An analytical simulation technique for cone-beam CT and pinhole SPECT

This study was aimed at developing an efficient simulation technique with an ordinary PC.The work involved derivation of mathematical operators,analytic phantom generations,and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging.The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring.The 3D Shepp-Logan,Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions.The reconstructed phantom images were of good accuracy with the phantoms.The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging.

Strategies for Segmenting the Upper Airway in Cone-Beam Computed Tomography (CBCT) Data

The wide availability, low radiation dose and short acquisition time of Cone-Beam CT (CBCT) scans make them an attractive source of data for compiling databases of anatomical structures. However CBCT has higher noise and lower contrast than helical slice CT, which makes segmentation more challenging and the optimal methods are not yet known. This paper evaluates several methods of segmenting airway geometries (nares, nasal cavities and pharynx) from typical dental quality head and neck CBCT data. The nasal cavity has narrow and intricate passages and is separated from the paranasal sinuses by thin walls, making it is susceptible to either over- or under-segmentation. The upper airway was split into two: the nasal cavity and the pharyngeal region (nasopharynx to larynx). Each part was segmented using global thresholding, multi-step level-set, and region competition methods (the latter using thresholding, clustering and classification initialisation and edge attraction techniques). The segmented 3D surfaces were evaluated against a reference manual segmentation using distance-, overlap- and volume-based metrics. Global thresholding, multi-step level-set, and region competition all gave satisfactory results for the lower part of the airway (nasopharynx to larynx). Edge attraction failed completely. A semi-automatic region-growing segmentation with multi-thresholding (or classification) initialization offered the best quality segmentation. With some minimal manual editing, it resulted in an accurate upper airway model, as judged by the similarity and volumetric indices, while being the least time consuming of the semi-automatic methods, and relying the least on the operator’s expertise.

Derivative-Hilbert-Backprojection based image reconstruction from truncated projections in helical cone-beam CT

In helical cone-beam computed tomography(CT), Feldkamp-Davis-Kress(FDK) based image reconstruction algorithms are by far the most popular. However, artifacts are commonly met in the presence of lateral projection truncation. The reason is that the ramp filter is global. To restrain the truncation artifacts, an approximate reconstruction formula is proposed based on the Derivative-Hilbert-Backprojection(DHB) framework. In the method, the first order derivative filter is followed by the Hilbert transform. Since the filtered projection values are almost zero by the first order derivative filter, the following Hilbert transform has little influence on the projection values, even though the projections are laterally truncated. The proposed method has two main advantages. First, it has comparable computational efficiency and image quality as well as the conventional helical FDK algorithm for non-truncated projections. The second advantage is that images can be reconstructed with acceptable quality and much lower computational cost in comparison to the Laplace operator based algorithm in cases with truncated projections. To point out the advantages of our method, simulations on the computer and real data experiments on our laboratory industrial cone-beam CT are conducted. The simulated and experimental results demonstrate that the method is feasible for image reconstruction in the case of projection truncation.

Delivered Dose Verification for Lung Cancer Stereotactic Body Radiotherapy Using Cone-Beam CT

Purpose: Verified the delivered dose distribution of lung cancer Stereotactic Body Radiotherapy (SBRT) using the cone-beam CT images. Methods: Twenty lung cancer patients who underwent SBRT with 100 CBCT images were enrolled in this study. Delivered dose distributions were recalculated on CBCT images with the deformed and non-deformed methods, respectively. The planned and delivered dose distributions were compared using the dose-volume histograms. Results: The delivered target coverage (V100) per patient inside target volume deviated on average were 0.83% ± 0.86% and 1.38% ± 1.40% for Pct vs. Pcbct and Pct vs. Pdcbct, respectively. The Conformity Index (CI) and Gradient Index (GI) showed a good agreement among the plans. For the critical organs, only minor differences were observed between the planned dose and the delivered dose. Conclusions: CBCT images were a useful tool for setup and dose delivery verification for lung cancer patients who underwent SBRT.

基于锥形线束CT的上颌后牙区牙槽骨增龄性变化研究

目的·测量分析上颌骨后牙区皮质骨厚度,以及牙槽骨高度和宽度的增龄性变化。方法·收集2019年1月—2022年12月于上海交通大学医学院附属瑞金医院口腔科就诊的种植患者锥形线束CT(cone-beam CT,CBCT)资料,其中青年组(18~30岁)40例、老年组(≥60岁)40例,男女比例为1∶1。应用i-Dixel软件分别对牙列整齐的一侧上颌后牙牙间3个区域(区域Ⅰ为上颌第一前磨牙和第二前磨牙间,区域Ⅱ为上颌第二前磨牙和第一磨牙间,区域Ⅲ为上颌第一磨牙和第二磨牙间)的牙槽骨颊、腭侧皮质骨厚度,以及牙槽骨宽度和高度进行测量,比较不同组间的差异。结果·在区域Ⅲ,老年男性颊侧皮质骨厚度[(1.49±0.29)mm]显著大于青年男性[(1.11±0.34)mm](P<0.001);在区域Ⅰ、Ⅱ,老年女性腭侧皮质骨厚度[区域Ⅰ:(1.27±0.30)mm;区域Ⅱ:(1.28±0.27)mm]均显著小于青年女性[区域Ⅰ:(1.70±0.32)mm;区域Ⅱ:(1.58±0.61)mm](均P<0.05)。牙槽骨宽度在3个区域均呈现老年组小于青年组的趋势,但仅在区域Ⅱ、Ⅲ,老年男性[区域Ⅱ:(8.61±1.15)mm;区域Ⅲ:(11.06±2.40)mm]与青年男性[区域Ⅱ:(10.29±1.69)mm;区域Ⅲ:(13.39±1.59)mm]之间差异有统计学意义(均P<0.05)。牙槽骨高度在区域Ⅰ、Ⅱ,老年男性和老年女性分别显著大于青年男性和青年女性(均P<0.05)。老年组中,男性颊侧皮质骨厚度在区域Ⅰ、Ⅲ均显著大于女性(均P<0.05)。结论·女性上颌后牙区腭侧皮质骨厚度随着年龄增加显著变薄;上颌后牙区牙槽骨宽度随着年龄增长都呈现缩窄趋势,老年男性变化尤为显著;老年人上颌后牙区牙槽骨的高度显著增加。

基于Halcyon加速器百分百图像引导模式下盆腔肿瘤CTV-PTV边界外放的研究

目的探讨基于Halcyon加速器百分百图像引导模式下盆腔肿瘤临床靶区-计划靶区(Clinical Target Volume,CTV)-(Planning Target Volume,PTV)边界外放的摆位误差。方法选取2023年1—5月在Halcyon加速器上行调强放射治疗的19例盆腔肿瘤患者为研究对象,采集每个患者分次间、纠正后、分次内300套共900个锥形束CT图像,与计划CT进行配准融合,得到三维方向上的矢量误差,用X(左右)方向、Y(头脚)方向、Z(腹背)方向表示。计算摆位误差及分布趋势,并根据纠正后及分次内的摆位误差计算CTV-PTV的外放边界。结果X方向上,分次间、纠正后、分次内的摆位绝对误差分别为(2.07±1.82)、(0.19±0.19)、(0.30±0.28)mm;Y方向上,分次间、纠正后、分次内的摆位绝对误差分别为(3.87±2.67)、(0.23±0.31)、(0.27±0.23)mm;Z方向上,分次间、纠正后、分次内的摆位绝对误差分别为(0.72±0.83)、(0.20±0.22)、(0.30±0.27)mm,差异均有统计学意义(P<0.05)。纠正后和分次内X、Y、Z 3个方向分别有97%和96.33%的摆位误差在1 mm以内。CTV-PTV外放边界从6.36 mm缩小到1.06 mm。结论从摆位误差角度来看,基于Halcyon加速器百分百图像引导模式下的盆腔肿瘤治疗,根据纠正后和分次内的摆位误差计算CTV-PTV外放边界为1.1 mm。通过Halcyon加速器治疗盆腔肿瘤患者可降低摆位误差,提高患者靶区和危及器官的安全精度,缩小CTV-PTV边界外放值,减少正常组织的累及体积。

不同垂直骨面型下颌第一磨牙横向位置差异的CBCT研究

目的:使用锥形束CT(cone beam CT,CBCT)测量不同垂直骨面型下颌第一磨牙生理牙槽骨厚度,评估横向磨牙位置。方法:选取2023年1~10月在合肥市口腔医院正畸二科就诊患者50例,分为高角组、均角组及低角组,术前拍摄CBCT,数据导入配套三维软件进行4个部位不同深度牙槽骨厚度的测量分析。结果:高角患者下颌第一磨牙的骨厚度最小。下颌第一磨牙舌侧骨厚度高于颊侧。下颌第一磨牙釉牙骨质界根方4 mm处近中舌侧牙槽骨厚度高于远中舌侧,近中颊侧牙槽骨厚度与远中颊侧比较差异无统计学意义。下颌第一磨牙釉牙骨质界根方8 mm处远中颊侧牙槽骨厚度高于近中颊侧,近中舌侧的牙槽骨厚度与远中舌侧比较差异无统计学意义。下颌第一磨牙同一测量位点釉牙骨质界根方8 mm的牙槽骨厚度高于根方4 mm的牙槽骨厚度。结论:不同的垂直骨面型、测量部位、测量深度、牙齿解剖形态都会反映出下颌第一磨牙在牙槽骨中横向位置的差异。

3D/4D CT和3D/4D CBCT在不同运动模式下的模体靶区体积差异

目的评估3D/4D CT和3D/4D CBCT在不同运动模式下模体的内靶区成像的体积差异,以期探讨不同运动模式下各种成像方式在肺体部立体定向放射治疗(SBRT)的图像引导放疗应用的准确性。方法本研究采用CIRS胸部动态模体模拟呼吸运动,使用直径3 cm小球插件,设定振幅分别为5 mm、10 mm的sin(x)和cos 4(x)波形的运动曲线,周期4 s,分别采集3D/4D CT(飞利浦CT)和3D/4D CBCT(医科达加速器)图像,测量不同运动模式下,3D CT、4D CT的平均密度投影CT(4D CT-AIP)、4D CT的最大密度投影CT(4D CT-MIP)、4D CT的全部时相(4D CT-ALL%)和3D CBCT、4D CBCT的平均密度投影CT(4D CBCT-AIP)、4D CBCT的最大密度投影CT(4D CBCT-MIP)各自图像插件小球内靶区体积并进行分析。结果3D CT的靶区体积最小;4D CT-ALL、4D CT-MIP和4D CBCT-MIP三者靶区体积大小接近;3D CT的ITV与ITV-ALL的相似度最低,3D CBCT的ITV与ITV-ALL的相似度接近,4D CT和4D CBCT的ITV(MIP-ALL)的相似度最高,4D CT和4D CBCT图像ITV(AIP-ALL)的相似度均低于ITV(MIP-ALL)。结论对于运动靶区,4D CT联合4D CBCT更能准确提供各时相的肿瘤靶区勾画和运动轨迹验证,是一种可靠的肺SBRT定位及引导模式。

D-CBCT在肺癌容积旋转调强计划精准治疗中的临床应用

目的探讨椎形束CT(D-CBCT)在肺癌容积旋转调强(VMAT)计划精准治疗中的临床应用。方法选取2019年10月~2022年10月在南通市第三人民医院放射治疗科就诊的100例肺癌患者。根据CBCT扫描模式不同,分为4D组(n=57)和3D组(n=43)。比较两组患者放疗摆位误差、内靶区(ITV)体积、靶区剂量、心脏受照剂量和肿瘤控制效果。结果在校正前后和治疗后,两组各摆位误差绝对值无统计学差异(P>0.05);4D组患者中下叶肿瘤ITV体积低于3D组(P<0.05);4D组的最大剂量(D_(max))、最小剂量(D_(min))和平均剂量(D_(mean))靶区剂量均高于3D组(P<0.05);4D组的V10、V20、V30及平均受量(D_(mean))等心脏受照剂量均低于3D组(P<0.05);4D组和3D组患者的客观有效率无明显差异(P>0.05)。结论可将D-CBCT应用于肺癌容积旋转调强计划精准治疗中,尤其采用4D-CBCT可更好提供靶区剂量,减少肺癌患者的中下叶肿瘤ITV体积和心脏受照剂量。