Progress in image-guided radiotherapy for the treatment of non-small cell lung cancer

Lung cancer is one of the most common malignant tumors. It has the highest incidence and mortality rate of all cancers worldwide. Late diagnosis of nonsmall cell lung cancer(NSCLC) is very common in clinical practice, and most patients miss the chance for radical surgery. Thus, radiotherapy plays an indispensable role in the treatment of NSCLC. Radiotherapy technology has evolved from the classic two-dimensional approach to three-dimensional conformal and intensity-modulated radiotherapy. However, how to ensure delivery of an accurate dose to the tumor while minimizing the irradiation of normal tissues remains a huge challenge for radiation oncologists, especially due to the positioning error between fractions and the autonomous movement of organs. In recent years, image-guided radiotherapy(IGRT) has greatly increased the accuracy of tumor irradiation while reducing the irradiation dose delivered to healthy tissues and organs. This paper presents a brief review of the definition of IGRT and the various technologies and applications of IGRT. IGRT can help ensure accurate dosing of the target area and reduce radiation damage to the surrounding normal tissue. IGRT may increase the local control rate of tumors and reduce the incidence of radio-therapeutic complications.

Biological effects of human lung cells MRC-5 in CBCT positioning for image-guided radiotherapy

Image-guided radiotherapy(IGRT) provides precise positioning for the tumor target, but it may bring extra irradiation dose in the target positioning with a cone beam CT(CBCT) which has been increasingly used in IGRT. In this work, we focused on biological effects of the low-dose irradiation in IGRT, which have not been considered so far. Primary human fibroblasts cells from the lung and MRC-5 were irradiated by a CBCT. DNA doublestrand breaks(c-H2 AX foci) and micronucleus frequency of the irradiated samples were analyzed. Compared to the control, the c-H2 AX foci yields of the samples irradiated to 16 m Gy increased significantly, and the micronuclei rate of the samples irradiated for 3 days increased notably. The dose by imaging guidance device can be genotoxic to normal tissue cells, suggesting a potential risk of a secondary cancer. The effects, if confirmed by clinical studies,should be considered prudentially in designing IGRT treatment plans for the radiosensitive population, especially for children.

Long-term clinical outcomes of lipiodol marking using standard gastroscopy for image-guided radiotherapy of upper gastrointestinal cancers

BACKGROUND Image-guided radiotherapy(IGRT)has significantly improved the precision in which radiotherapy is delivered in cancer treatment.Typically,IGRT uses bony landmarks and key anatomical structures to locate the tumor.Recent studies have demonstrated the feasibility of peri-tumor fiducials in enabling even more accurate delineation of target and normal tissue.The use of gold coils as fiducials in gastrointestinal tumors has been extensively studied.However,placement requires expertise and specialized endoscopic ultrasound equipment.This article reports the long-term outcomes of using a standard gastroscopy to inject liquid fiducials for the treatment of oesophageal and gastric tumors with IGRT.AIM To assess the long-term outcomes of liquid fiducial-guided IGRT in a cohort of oesophageal and gastric cancer patients.METHODS A retrospective cohort study of consecutive adults with Oesophagogastric cancers referred for liquid fiducial placement before definitive/neo-adjuvant or palliative IGRT between 2013 and 2021 at a tertiary hospital in Melbourne,Australia was conducted.Up to four liquid fiducials were inserted per patient,each injection consisting of 0.2-0.5mL of a 1:1 mixture of iodized oil(Lipiodol;Aspen Pharmacare)and n-butyl 2-cyanoacrylate(Histoacryl®;B.Braun).A 23-gauge injector(Cook Medical)was used for the injection.All procedures were performed by or under the supervision of a gastroenterologist.Liquid fiducial-based IGRT(LF-IGRT)consisted of computer-assisted direct matching of the fiducial region on cone-beam computerised tomography at the time of radiotherapy.Patients received standard-IGRT(S-IGRT)if fiducial visibility was insufficient,consisting of bone match as a surrogate for tumor position.Radiotherapy was delivered to 54Gy in 30 fractions for curative patients and up to 45Gy in 15 fractions for palliative treatments.RESULTS 52 patients were referred for liquid fiducial placement within the study period.A total of 51 patients underwent liquid fiducial implantation.Of these a total of 31 patients received radiotherapy.Among these,the median age was 77.4 years with a range between 57.5 and 88.8,and 64.5%were male.Twenty-seven out of the 31 patients were able to have LF-IGRT while four had S-IGRT.There were no complications after endoscopic implantation of liquid fiducials in our cohort.The cohort overall survival(OS)post-radiotherapy was 19 mo(range 0 to 87 mo).Whilst the progression-free survival(PFS)post-radiotherapy was 13 mo(range 0 to 74 mo).For those treated with curative intent,the median OS was 22.0 mo(range 0 to 87 mo)with a PFS median of 14.0 mo(range 0 to 74 mo).Grade 3 complication rate post-radiotherapy was 29%.CONCLUSION LF-IGRT is feasible in 87.1%of patients undergoing liquid fiducial placement through standard gastroscopy injection technique.Our cohort has an overall survival of 19 mo and PFS of 13 mo.Further studies are warranted to determine the long-term outcomes of liquid-fiducial based IGRT.

光学体表成像设备Catalyst的故障维修案例及日常保养方法

本文介绍了光学体表成像设备Catalyst HD的工作原理,以及处理常见的硬件和软件故障的方法,并提供了日常维护保养方法。其中,对于硬件故障,利用Catalyst HD系统的MutilZsn软件来判断Catalyst投影器和摄像头故障,对于软件故障方面,探讨了Catalyst HD系统在医用直线加速器上常见的Authorization Pending联锁问题的触发原因。本文为科室更好地开展光学体表引导放疗技术,高效地运用好设备提供参考意见。

光学体表监测技术引导的放射治疗应用现状与前景

光学体表监测技术(surface guided radiation therapy,SGRT)是一种在放射治疗过程中对患者进行连续体位监测的无辐射、无创性技术,通过先进的3D光学表面定位及追踪技术,快速获取患者的体表轮廓信息,生成高精度的3D体表轮廓,可在放射治疗期间对患者进行实时监测,保证放射治疗的精准性。SGRT已广泛应用于乳腺、颅内、头颈和四肢等不同部位肿瘤的放射治疗中,其优势在于减少初始摆位误差、实时监测治疗过程,并与呼吸门控和深吸气屏气治疗技术相结合。SGRT还可通过减少锥形束CT的使用进而降低辐射剂量,提高患者应用固定装置的舒适性,提升临床工作效率和安全性等。本文阐述SGRT常用系统及其临床应用,并探讨其局限性和未来发展前景。

Catalyst光学体表监测在左侧乳腺癌ABC-DIBH放射治疗中的应用

目的 探讨在应用主动呼吸控制(Active Breathing Control,ABC)技术的左侧乳腺癌深吸气屏气(Deep Inspiration Breath Hold,DIBH)放疗中,使用光学体表追踪技术监测屏气的有效性和体位的重复性效果,以保证患者在放疗中吸气方式一致和体位不变,提高放射治疗的精确性。方法 选取应用ABC技术放疗的23例左侧乳腺癌患者为研究对象,以Catalyst进行治疗中DIBH体位监测,以分次内锥形束计算机断层扫描(Cone Beam Computed Tomography,CBCT)为参考标准,分别记录二者误差数据,应用Pearson法和Bland-Altman法分别评估两组误差的相关性和两种系统的一致性。将光学体表监测值与CBCT配准误差值之间的差值定义为Catalyst体表监测精度。结果 Catalyst监测在左右(x轴)方向、头脚(y轴)方向和前后(z轴)方向误差分别为(0.08±1.04)、(1.44±2.15)、(0.45±1.69)mm,CBCT配准误差分别为(0.15±1.15)、(1.51±2.28)、(0.44±1.81)mm。x轴方向和z轴方向相关系数r值分别为0.60、0.77,呈强相关;y轴方向r值为0.82,呈极强相关。二者95%CI值在x、y与z轴方向分别为[-2.01,1.86]、[-2.69,2.57]、[-2.32,2.34] mm,Catalyst监测精度在x、y、z轴方向分别为(-0.08±0.99)、(-0.06±1.34)、(0.01±1.19)mm。结论 Catalyst可有效监测使用ABC进行治疗左侧乳腺癌患者的屏气状态,能准确且实时监测患者位置,提高治疗精确度,具有临床应用价值。

Technical advances in external radiotherapy for hepatocellular carcinoma

Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma(HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy(IMRT), stereotactic ablative body radiotherapy(SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy.

Advances in radiotherapy and targeted therapies for rectal cancer

The last decade witnessed a significant progress in understanding the biology and immunology of colorectal cancer alongside with the technical innovations in radiotherapy.The stepwise implementation of intensitymodulated and image-guided radiation therapy by means of megavolt computed tomography and helical tomotherapy enabled us to anatomically sculpt dose delivery,reducing treatment related toxicity.In addition,the administration of a simultaneous integrated boost offers excellent local control rates.The novel challenge is the development of treatment strategies for medically inoperable patient and organ preserving approaches.However,distant control remains unsatisfactory and indicates an urgent need for biomarkers that predict the risk of tumor spread.The expected benefit of target?ed therapies that exploit the tumor genome alone is so far hindered by high cost techniques and pharmaceuticals,hence hardly justifying rather modest improvements in patient outcomes.On the other hand,the immune landscape of colorectal cancer is now better clarified with regard to the immunosuppressive network that promotes immune escape.Both N2 neutrophils and myeloid-derived suppressor cells(MDSC)emerge as useful clinical biomarkers of poor prognosis,while the growing list of anti-MDSC agents shows promising ability to boost antitumor T-cell immunity in preclinical settings.Therefore,integration of genetic and immune biomarkers is the next logical step towards effective targeted therapies in the context of personalized cancer treatment.

Cage-like radiotherapy system for noncoplanar radiotherapy

The aim of this study was to design a cage-like radiotherapy system(CRTS)to further promote the clinical application of noncoplanar radiotherapy.The CRTS comprises two stands,two O-rings,several arc girders,an X-ray head,an imaging subsystem,and a treatment couch.The X-ray head rotates with O-rings around the patient’s body and slides along the arc girder.Compared with the C-arm linear accelerator(C-Linac),the clinically available spatial irradiation angle ranges(SIARs)of the CRTS for the head,chest,and abdomen were 33%,63.6%,and 62.6%larger,respectively.Moreover,according to a preliminary planning comparison based on the dose distribution simulation method,the CRTS achieved much better protection of normal tissue than the C-Linac.Furthermore,the CRTS enabled accurate noncoplanar irradiation without movement of the body being irradiated,allowed automatic control of the movements of different parts without risk of collisions,and provided continuous radiation over an angle that considerably exceeded a full turn.These advantages make CRTS very promising for noncoplanar radiotherapy.

Strategies to tackle the challenges of external beam radiotherapy for liver tumors

Primary and metastatic liver cancer is an increasingly common and difficult to control disease entity.Radiation offers a non-invasive treatment alternative for these patients who often have few options and a poor prognosis.However,the anatomy and aggressiveness of liver cancer poses significant challenges such as accurate localization at simulation and treatment,management of motion and appropriate selection of dose regimen.This article aims to review the options available and provide information for the practical implementation and/or improvement of liver cancer radiation programs within the context of stereotactic body radiotherapy and image-guided radiotherapy guidelines.Specific patient inclusion and exclusion criteria are presented given the significant toxicity found in certain sub-populations treated with radiation.Indeed,certain sub-populations,such as those with tumor thrombosis or those with larger lesions treated with transarterial chemoembolization,have been shown to have significant improvements in outcome with the addition of radiation and merit special consideration.Implementing a liver radiation programrequires three primary challenges to be addressed:(1) immobilization and motion management;(2) localization;and(3) dose regimen and constraint selection.Strategies to deal with motion include simple internal target volume(ITV) expansions,non-gated ITV reduction strategies,breath hold methods,and surrogate marker methods to enable gating or tracking.Localization of the tumor and organs-at-risk are addressed using contrast infusion techniques to take advantage of different normal liver and cancer vascular anatomy,imaging modalities,and margin management.Finally,a dose response has been demonstrated and dose regimens appear to be converging.A more uniform approach to treatment in terms of technique,dose selection and patient selection will allow us to study liver radiation in larger and,hopefully,multicenter randomized studies.

Incorporating GSA-SPECT into CT-based dose-volume histograms for advanced hepatocellular carcinoma radiotherapy

In single photon emission computed tomography-based three-dimensional radiotherapy(SPECT-B-3DCRT), im-ages of Tc-99 m galactosyl human serum albumin(GSA), which bind to receptors on functional liver cells, are merged with the computed tomography simulation im-ages. Functional liver is defined as the area of normal liver where GSA accumulation exceeds that of hepato-cellular carcinoma(HCC). In cirrhotic patients with a gigantic, proton-beam-untreatable HCC of ≥ 14 cm in diameter, the use of SPECT-B-3DCRT in combination with transcatheter arterial chemoembolization achieved a 2-year local tumor control rate of 78.6% and a 2-year survival rate of 33.3%. SPECT-B-3DCRT was applied to HCC to preserve as much functional liver as possible. Sixty-four patients with HCC, including 30 with Child B liver cirrhosis, received SPECT-B-3DCRT and none ex-perienced fatal radiation-induced liver disease(RILD). The Child-Pugh score deteriorated by 1 or 2 in > 20% of functional liver volume that was irradiated with ≥ 20 Gy. The deterioration in the Child-Pugh score decreased when the radiation plan was designed to irradiate ≤ 20% of the functional liver volume in patients givendoses of ≥ 20 Gy(FLV20Gy). Therefore, FLV20 Gy ≤ 20% may represent a safety index to prevent RILD during 3DCRT for HCC. To supplement FLV20 Gy as a qualitative index, we propose a quantitative indicator, F 20 Gy, which was calculated as F 20 Gy = 100% ×(the GSA count in the area irradiated with ≥ 20 Gy)/(the GSA count in the whole liver).

Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma

A clinical trial of radiotherapy with modified simultaneous integrated boost(SIB)technique against huge tumors was conducted.A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial.The total dose of 77 Gy(equivalent dose in 2Gy/fraction)and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively,andapproximately 20%dose escalation was achieved with the modified SIB technique.The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy.Performance status of the patient improved from 4 to 0.Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance,improvement of QOL,and prolongation of survival.

Stereotactic Radiotherapy Planning Using Modified Dynamic Conformal Arcs under Considering the Possibility for Amended Visual Organ Displacement Resulting from Early Tumor Shrinkage during Treatment for Perioptic Involvement of Myeloma

Treatment planning of radiotherapy for skull base involvement of multiple myeloma presenting with visual impairment should be optimized to alleviate symptoms immediately and sufficiently while minimizing toxicities. Two such patients were treated with fractionated stereotactic radiotherapy by using Dynamic Conformal Arcs (DCA) under image guidance based on bony anatomy alignment. DCA planning was optimized after considering the possibility for amendment of visual organ displacement resulting from early tumor shrinkage during treatment through 1) the use of a target volume with modified geometry as a surrogate for leaf adaptation in order to improve target coverage, and 2) manual adjustment of a subset of leaf positions to reduce the dose gradient immediately inside the target boundary facing the visual organs and to eliminate an undesirable dose hotspot. In both cases, anticipated geometric changes in the target volume associated with improvement of visual organ displacement toward the target centroid were observed before the completion of treatment. Favorable visual functional outcomes as well as local tumor control were achieved during 14 months and 4 months follow-up periods. Notably, inexorable visual loss in one patient was fully reversed within one month after radiotherapy. We described the modification techniques for DCA planning in detail.

基于Sentinel/Catalyst光学体表监测系统引导下的体表图像引导放疗技术在肿瘤放射治疗中的应用研究

光学体表引导放疗(SGRT)可在患者治疗过程中实现全程监控,提供连续图像,在为肿瘤患者获得更精确、安全的放疗中展现了越来越重要的作用。该文就SGRT放疗技术治疗四肢肿瘤、体部肿瘤、头颈部肿瘤的应用场景、具体应用方案及技术进展等作一综述。

鼻咽癌表面引导放疗中2种参考表面的摆位准确性研究

目的:比较鼻咽癌表面引导放疗(surface-guided radiation therapy,SGRT)中基于容积重建技术(volume rende-ring technique,VRT)参考表面和基于医学数字成像和通信(digital imaging and communications in medicine,DICOM)参考表面的摆位准确性。方法:选取2020年4—10月某院收治的20例采用塑形垫结合热塑网膜固定的鼻咽癌放疗患者。在首次锥形束CT(cone beam CT,CBCT)图像引导下完成治疗后,取下热塑网膜,基于光学表面监测系统(optical surface monitoring system,OSMS)获取患者的VRT参考表面,过程中嘱患者维持体位不变;DICOM参考表面则基于由患者的定位CT影像提取出的体表轮廓数据获得。在第5、10、15次放疗(CBCT图像引导)完成后,基于VRT和DICOM 2种参考表面分别测量患者6个维度的摆位误差。采用Python的Stats工具对基于2种参考表面测量的摆位误差分别进行维度相关性分析,以检查各个维度摆位误差之间的独立性。通过独立性检验后,对基于2种参考表面测量的每个维度的摆位误差数据进行Wilcoxon秩和检验。结果:基于2种参考表面测量的摆位误差在各个维度上相互独立,且基于VRT参考表面测量的6个维度上的摆位误差均小于基于DICOM参考表面测量的摆位误差。但基于2种参考表面测量的6个维度的摆位误差间的差异未随治疗进展而增大。结论:在采用塑形垫结合热塑网膜体位固定方式的鼻咽癌SGRT中,基于VRT参考表面的摆位准确性和一致性优于DICOM参考表面。

光学体表引导摆位在乳腺癌保乳放疗中的应用

目的 评估光学体表引导放疗技术(surface guided radiation therapy, SGRT)在乳腺癌保乳放疗患者日常摆位应用的准确性。方法 以ELEKTA infinity加速器行乳腺癌保乳术后放疗的40例患者为研究对象,患者使用光学体表监测系统(optical surface monitoring system, OSMS)摆位,前3次治疗均行锥形束CT(cone-beam computed tomography, CBCT)验证,后续每周至少1次。记录OSMS摆位、CBCT配准和体表标记线对应的左右(ML)、头脚(SI)、前后(AP)的床值,分析OSMS与CBCT的差值(SG)和体表标记线与CBCT的差值(SM)之间的差异,并统计SG和SM的误差频值、SG摆位的旋转角度;用Bland-Altman法评估SG与CBCT的一致性;根据计划靶区外放公式MPTV=2.5Σ+0.7σ计算SG和SM的外扩边界。结果 SG在ML、SI、AP方向平移误差的中位数(0~0.1 cm)均小于SM(0~0.3 cm),差异有统计学意义(P<0.05);SG在ML、SI、AP方向平移误差绝对值≤0.3 cm的比例分别比SM高14.8%、16.3%、35.1%,SG摆位的Pitch、Roll、Yaw旋转误差中位数区间为(-0.10~0.10)°;在Bland-Altman散点图中,ML、SI、AP 3个平移方向上,SG与CBCT的差值均值为0.03 cm、0.01 cm和0.13 cm;SG和SM在ML、SI、AP方向的M值分别为(0.36 cm、0.38 cm、0.30 cm)、(0.66 cm、0.82 cm、0.93 cm)。结论 在乳腺癌保乳放疗中,SGRT引导摆位可以有效地减少摆位误差,降低PTV外扩边界,与CBCT具有较好的一致性。

Hi'CT:a pixel sensor-based device for ion tomography

Carbon ions,commonly referred to as particle therapy,have become increasingly popular in the last decade.Accurately predicting the range of ions in tissues is important for the precise delivery of doses in heavy-ion radiotherapy.Range uncertainty is currently the largest contributor to dose uncertainty in normal tissues,leading to the use of safety margins in treatment planning.One potential method is the direct relative stopping measurement(RSP)with ions.Heavy-ion CT(Hi′CT),a compact segmented full digital tomography detector using monolithic active pixel sensors,was designed and evaluated using a 430 MeV/u high-energy carbon ion pencil beam in Geant4.The precise position of the individual carbon ion track can be recorded and reconstructed using a 30μm×30μm small pixel pitch size.Two types of customized image reconstruction algorithms were developed,and their performances were evaluated using three different modules of CAT-PHAN 600-series phantoms.The RSP measurement accuracy of the tracking algorithm for different types of materials in the CTP404 module was less than 1%.In terms of spatial resolution,the tracking algorithm could achieve a 20%modulation transfer function normalization value of CTP528 imaging results at 5 lp/cm,which is significantly better than that of the fast imaging algorithm(3 lp/cm).The density resolution obtained using the tracking algorithm of the customized CTP515 was approximately 10.5%.In conclusion,a compact digital Hi'CT system was designed,and its nominal performance was evaluated in a simulation.The RSP resolution and image quality provide potential feasibility for scanning most parts of an adult body or pediatric patient,particularly for head and neck tumor treatment.

Static superconducting gantry‑based proton CT combined with X‑ray CT as prior image for FLASH proton therapy

Proton FLASH therapy with an ultra-high dose rate is in urgent need of more accurate treatment plan system(TPS)to promote the development of proton computed tomography(CT)without intrinsic error compared with the transformation from X-ray CT.This paper presents an imaging mode of proton CT based on static superconducting gantry different from the conventional rotational gantry.The beam energy for proton CT is fixed at 350 MeV,which is boosted by a compact proton linac from 230 MeV,and then delivered by the gantry to scan the patient’s body for proton imaging.This study demonstrates that the static superconducting gantry-based proton CT is effective in clinical applications.In particular,the imaging mode,which combines the relative stopping power(RSP)map from X-ray CT as prior knowledge,can produce much a higher accuracy RSP map for TPSs and positioning and achieve ultra-fast image for real-time image-guided radiotherapy.This paper presents the conceptual design of a boosting linac,static superconducting gantry and proton CT imaging equipment.The feasibility of energy enhancement is verified by simulation,and results from Geant4 simulations and reconstruction algorithms are presented,including the simulation verification of the advantage of the imaging mode.

光学体表监测系统在乳腺癌改良根治术后放疗中的应用研究

目的利用光学体表监测系统(optical surface monitoring system,OSMS)对颈胸一体架固定下乳腺癌改良根治术后放疗患者进行辅助摆位,研究其对锁骨上下区摆位误差及肩锁关节摆位重复性的影响。方法选取2021年5月至8月于中国医学科学院北京协和医学院肿瘤医院接受乳腺癌改良根治术后放疗的患者32例,通过OSMS辅助摆位,应用“Treatment”功能校正患者手臂等部位位置和身体角度以提高摆位精准性。治疗过程中使用OSMS辅助摆位(OSMS辅助摆位组)和仅使用体表标记线常规摆位(常规摆位组)依次交替进行,将加速器机载锥形束CT(cone-beam CT,CBCT)扫描获取的图像与模拟定位CT图像进行配准,记录患者X(左右方向)、Y(头脚方向)和Z(腹背方向)轴以及3个绕轴旋转方向Rx、Ry和Rz的摆位误差,并分别测量肩锁关节的移动幅度和三维空间位移,对误差值进行分析计算。统计学分析采用配对样本t检验与秩和检验。结果入组32例病例,共行142次CBCT扫描和142次OSMS+CBCT扫描。OSMS辅助摆位组和常规摆位组在X、Y以及Z轴方向上的平移摆位误差分别为(0.17±0.12)cm和(0.21±0.15)cm(P=0.394)、(0.14±0.13)cm和(0.24±0.19)cm(P=0.026)以及(0.13±0.12)cm和(0.19±0.21)cm(P=0.591),在Rx、Ry和Rz方向上的旋转摆位误差分别为(0.60±0.52)°和(0.51±0.52)°(P=0.344),(0.61±0.60)°和(0.75±0.71)°(P=0.195),(0.65±0.62)°和(0.85±0.65)°(P=0.025)。两组肩锁关节的动度ΔX、ΔY以及ΔZ分别为(0.12±0.10)cm和(0.13±0.10)cm(P=0.546)、(0.10±0.13)cm和(0.10±0.12)cm(P=0.565)以及(0.11±0.12)cm和(0.12±0.13)cm(P=0.009);肩锁关节的空间位移分别为(0.16±0.14)cm和(0.17±0.13)cm(P=0.066)。结论应用OSMS光学体表摆位可以减小头脚方向的平移摆位误差,减小肩锁关节在腹背方向的动度和空间位移。

有无CT端光学定位设备对光学表面引导的左侧乳腺癌DIBH放疗摆位精度影响的研究

目的探讨光学表面引导左侧乳腺癌深吸气屏气(Deep Inspiration Breath-hold,DIBH)放疗过程中,无CT端光学设备定位与有CT端光学设备辅助定位2种模式对放疗摆位精度的影响。方法选取60例左侧乳腺癌患者,其中30例患者行无CT端光学设备DIBH定位后,通过光学表面监测系统OSMS(AlignRT)引导实施DIBH放疗(D0组);其他30例患者通过CT端光学设备Sentinel辅助DIBH定位后,通过Catalyst引导实施DIBH放疗(D1组)。比较2组定位流程,并分析2组患者首次放疗摆位时经CBCT配准后六维方向的误差数据。结果D0组在x、y、z和Rx、Ry、Rz六维方向的CBCT配准误差绝对值分别为(0.15±0.11)、(0.17±0.12)、(0.20±0.14)cm和(0.77±0.71)°、(0.60±0.60)°、(0.66±0.62)°,D1组为(0.13±0.08)、(0.13±0.09)、(0.20±0.11)cm和(0.61±0.57)°、(0.50±0.52)°、(0.61±0.46)°,2组配准数据比较差异均无统计学意义(P>0.05)。结论无CT端光学设备与有CT端光学设备定位,均可精准实现光学表面引导的左侧乳腺癌DIBH放疗摆位,两者CBCT配准误差无统计学差异。