胸上段食管癌断层定野与断层螺旋放疗和容积旋转调强放疗的剂量学比较

目的 比较胸上段食管癌断层定野放疗（TD）、断层螺旋放疗（HT）和容积旋转调强放疗（VMAT）的剂量学差异,为临床上食管癌放疗方式的选择提供依据。方法 选取15例临床分期为cT_2~4N_0~1M₀的胸上段食管癌患者,分别设计TD、HT和VMAT 3种计划。比较靶区的剂量体积直方图（DVH）、均匀指数（HI）、适形指数（CI）、危及器官（OAR）受量、治疗时间和机器跳数（MU）的差异。结果 HT和TD计划的D₂和D_mean均明显低于VMAT计划;TD计划的D₉₈和HT相似,但均高于VMAT计划。对于HI,HT < TD < VMAT,3组之间差异有统计学意义（F=81.603,P < 0.05）。3组计划的CI差异无统计学意义（P>0.05）。双肺的V₁₅,HT明显高于VMAT和TD （t=3.547、-2.626,P < 0.05）。TD计划的V₂₀与HT计划的相似,但高于VMAT计划（t=2.824、3.052, P < 0.05）。3组计划中的脊髓D_max无明显差异。HT和TD的执行时间、MU均高于VMAT,差异具有统计学意义（t=21.617、15.693、10.018、7.802,P < 0.05）。结论 与VMAT相比,HT和TD计划可明显改善胸上段食管癌靶区的剂量分布,可获得更好的适形度。但VMAT比HT或TD明显降低双肺V₂₀、MU及治疗时间。TD与HT相比,HT的靶区剂量分布更好,但TD降低了双肺的V₁₅,且缩短治疗时间。     

局限期小细胞肺癌累及野放疗淋巴结区域受照剂量与失败关系的研究

目的 分析局限期小细胞肺癌(small cell lung cancer, SCLC)患者采用累及野照射(involved field radiation therapy, IFRT)时各淋巴结区受照剂量与淋巴结失败的关系。方法 在接受根治性放疗的局限期SCLC患者原治疗计划中勾画第1至10组淋巴结引流区,记录每组淋巴结转移情况及其所受目的性或附带照射剂量。照射野内、野边缘、野外失败分别定义为失败淋巴结体积位于80%处方剂量曲线内、80%~20%、20%处方剂量曲线外。结果 勾画76例患者1 216组淋巴结引流区。中位随访时间17.4个月。初诊时各淋巴结区转移率超过50%的为4R(68.7%)、4L(57.9%)、10R(57.9%)、2R(56.6%)、7(51.3%)区。淋巴结区有阳性病灶时,均接受了处方剂量照射。而未发生转移时,受到平均附带照射剂量超过3 000 cGy的淋巴结区有:3P、4L、7、6、4R、5、2L。淋巴结中位无失败时间9.8个月。仅1例患者发生纵隔淋巴结照射野外失败。其余患者照射野外失败位于锁骨上区或原发病灶对侧肺门。结论 SCLC患者采用IFRT照射纵隔淋巴结区时,未发生转移的淋巴结区可以受到相当剂量的附带照射。而纵隔淋巴结照射野外失败较少见,与所受附带照射剂量贡献有关。     

乳腺癌保乳术后静态逆向调强与三维适形野中野放疗的剂量学比较

目的 比较早期乳腺癌保乳术后静态逆向调强(IMRT)与三维适形野中野瘤床同步加量(FIF)两种放疗技术的剂量学差异。方法 选择9例左侧早期乳腺癌保乳术后患者,分别设计IMRT与FIF两组放疗计划,处方剂量为乳房靶区50.4 Gy,分28次,每次1.8 Gy;瘤床靶区61.6 Gy,分28次,每次2.2 Gy。比较两组计划的靶区适形度及危及器官受量,并比较两者的计划优化和治疗时间。结果 IMRT的全乳靶区适形度(CI)为1.82±0.16,低于FIF的2.21±0.15(t=2.08,P<0.05);瘤床靶区适形度为1.19±0.04,低于FIF的1.59±0.11(t=3.97,P<0.05)。两组计划危及器官同侧肺的V₂₀和心脏的V₃₀无明显差异。FIF对侧肺的Dmax和Dmean分别是(5.41±2.76)和(0.51±0.10) Gy, IMRT分别为(25.72±2.61)和(7.46±0.39) Gy(t=-22.44、-21.14,P<0.05)。对侧乳房的Dmax和Dmean,FIF为(8.50±5.61)和(0.46±0.11) Gy,IMRT为(27.73±4.29)和(6.38±0.48) Gy(t=-5.66、-14.83,P<0.05)。对于对侧肺和乳房的低剂量照射区V₅,FIF为(0.09±0.09)%和(0.45±0.45)%,低于IMRT的(84.66±3.06)%和(60.79±4.94)%(t=-28.19、-12.80,P<0.05)。在计划优化及治疗时间方面,FIF与IMRT优化时间分别为(61.57±0.89)min和(241.28±1.06)min,单次治疗时间分别为(16.14±1.42)min和(29.85±0.59) min(t=-32.35、-8.82,P<0.05)。结论 IMRT改善了靶区适形度,但是增加了对侧肺和对侧乳房的受照剂量。FIF在计划优化时间及治疗时间方面有优势。     

中枢神经系统细胞型室管膜瘤与伸长细胞型室管膜瘤的MRI对比分析

目的 对比观察脑及脊髓细胞型(CE)与伸长型室管膜瘤(TE)的MRI表现,以提高对CE及TE病理亚型的进一步认识.方法 回顾性分析经手术病理证实的中枢神经系统CE 25例及TE 26例,观察肿块发生的部位、累及的范围、内部的信号特点、有无囊变/钙化、肿瘤的边界、对周围结构的影响、邻近脊髓是否形成空洞、是否有水肿、有无种植转移、增强扫描后的强化特点及强化幅度等.结果 25例CE,颅内8例,5例位于第四脑室,3例位于幕上脑实质;脊髓内17例.26例TE中,幕上脑实质内2例,位于左侧额叶,与侧脑室相通;髓内24例.CE与TE发生的部位、囊变的特点有显著性差异(P＜0.05),而发生肿瘤的年龄、性别、范围、信号特点、边界、脊髓空洞的形成、脊髓水肿及强化幅度未见明显差异.结论 脑及脊髓内CE及TE的MRI具有一定特征性表现,有助于术前诊断及指导临床治疗.     

周围型肺癌的大小与CT增强幅度的相关性研究

的:探讨周围型肺癌的大小与CT增强幅度的关系。方法:回顾分析6 7例周围型肺癌,测量其直径和CT增强幅度,进行相关性分析。结果:6 7例肺癌增强幅度是30 . 2±3 .7HU。依病灶直径大小分为4组,增强幅度分别是2 9 .3±3. 7HU、31 .2±4 . 1HU、30 . 8±2 9HU及2 .8 4±5 .1HU。结论:周围型肺癌CT增强幅度与病灶大小无相关性     

原发性透明细胞型肝癌的CT和MRI诊断

目的 探讨分析CT和MRI对原发性透明细胞型肝癌(primary clear cell carcinoma of the liver, PCCCL)的诊断价值。方法 选取41例经病理证实为PCCCL患者的CT和MRI资料,18例行CT检查,12例行MR检查,11例行CT和MR检查。结果 CT平扫27例为低密度,12例病灶内测得CT值为负值;2例呈稍高密度;MR平扫T₁WI呈稍低信号19例、稍高信号4例,T₁脂肪抑制信号减低;T₂WI呈混杂高信号22例,低信号1例;增强后36例呈动脉期强化,门脉期呈相对低密度/信号;14例肿瘤内见软组织结节伴结节状强化;27例见包膜伴延迟强化。结论 PCCCL是肝细胞肝癌的一种少见类型,影像表现与普通肝细胞癌既有相同之处,又有自身特点;瘤内脂肪成分、肿瘤内结节伴强化是其重要特征,强化方式仍以“快进快出”为主,假包膜出现率较高。     

T型锁定加压钢板与普通T型钢板治疗桡骨远端骨折的疗效比较

目的比较普通T型钢板内固定术与T型锁定加压钢板内固定术治疗桡骨远端骨折的疗效。方法52例桡骨远端骨折患者分为两组。一组行普通T型钢板内固定术(22例),另一组行T型锁定加压钢板内固定术(30例),比较两组的手术时间、术中出血量、骨折愈合时间及疗效。结果手术时间、术中出血量两组比较差异无统计学意义,骨折愈合时间及疗效两组比较差异有统计学意义(P均<0.05)。结论T型锁定加压钢板与普通T型钢板均可用于治疗桡骨远端骨折,但以T型锁定加压钢板效果更好。     

Chiari—Ⅰ型畸形的MRI与CT应用比较

本文对41例Chiari—I型畸形的CT与高场MR片进行了较全面的研究。其中CT片21例,MR片20例,有对照8例。在成像方位、对比度、伪影、安全性等方面做了较全面比较。介绍了两种成像的特点,在诊断中的优势及不足。目的在于充分认识CT与MR对该病的诊断价值,以正确选择诊断手段。     

低剂量辐射对小鼠脾脏和胸腺Ⅰ型和Ⅱ型辅助性T细胞的影响

目的研究低剂量辐射对Ⅰ型辅助性Ｔ细胞（Ｔｈ１）和Ⅱ型辅助性Ｔ细胞（Ｔｈ２）的影响，揭示低剂量辐射使Ｔｈ激活的分子机理。方法采用分子杂交方法，检测Ｘ射线全身照射后小鼠脾脏和胸腺细胞ＩＦＮ－γ和ＩＬ－６ｍＲＮＡ的表达。结果７５ｍＧｙＸ射线全身照射后小鼠脾脏和胸腺ＩＦＮ－γ和ＩＬ－６ｍＲＮＡ表达水平明显增高。结论低剂量辐射诱导Ｔｈ１和Ｔｈ２激活，其分子机理与其启动调节Ｔｈ１和Ｔｈ２克隆发育的细胞因子的基因表达有关     

5Hz和20Hz磁场对脑反应影响的比较研究

基于在脑电频率范围内的磁场刺激对脑过程可能有调制作用的假设，并在已取得 结构的基础上，本文在２２名正常被试者中比较了５Ｈｚ和２０Ｈｚ的磁场刺激对进行选择反应和选择心算时脑反应的影响。     

5Hz和20Hz磁场刺激对大鼠脑缺血影响的比较研究

目的 观察5Hz和20Hz磁场对脑缺血损害的影响。方法 采用左侧颈总动脉阻断致大鼠急性脑缺血,缺血后给予5Hz和20Hz的磁场刺激3h或5h。观察脑细胞的缺血性病理变化。结果 锥体细胞和星形胶质细胞表现出不同的缺血性病理变化;对锥体细胞的缺血性损害5Hz组轻于对照组和20Hz组,而对星形胶质细胞则表现为5Hz组的缺血性损害程度重于对照组和20Hz组;20Hz组的缺血性损害程度与对照组相似。结论 不同频率的磁场对大鼠脑急性缺血性损害有不同的影响,磁场的频率效应可能与磁场作用机制及细胞的不同特性有关。     

Clinical Implementation of Tangential Field Intensity Modulated Radiation Therapy (IMRT) Using Sliding Window Technique and Dosimetric Comparison with 3D Conformal Therapy (3DCRT) in Breast Cancer

The purpose of this study was to evaluate the clinical implementation of tangential field IMRT using sliding window technique and to compare dosimetric parameters with 3-dimensional conformal radiation therapy (3DCRT). Twenty breast cancer patients were randomly selected for comparison of intensity modulated radiation therapy (IMRT)-based treatment plan with 3DCRT. Inverse treatment was performed using the sliding window technique, employing the Eclipse^® Planning System (version 7.1.59, Varian, Palo Alto, CA). The dosimetric parameters compared were V₉₅ (the percentage of target volume getting ≥95% of prescribed dose), V₁₀₅, V₁₁₀, and dose homogeneity index, DHI (percentage of target volume getting between 95% and 110% of prescribed dose). The mean V₉₅, DHI, V₁₀₅, and V₁₁₀ for target volume for IMRT vs. 3D were 90.6% (standard deviation [SD]: 3.2) vs. 91% (SD: 3.0), 87.7 (SD: 6.0) vs. 82.6 (SD: 7.8), 27.3% (SD: 20.3) vs. 49.4% (SD: 14.3), and 2.8 (SD: 5.6) vs. 8.4% (SD: 7.4), respectively. DHI was increased by 6.3% with IMRT compared to 3DCRT (p < 0.05). The reductions of V₁₀₅ and V₁₁₀ for the IMRT compared to 3DCRT were 44.7% and 66.3%, respectively (p < 0.01). The mean dose and V₃₀ for heart with IMRT were 2.3 (SD: 1.1) and 1.05 (SD: 1.5) respectively, which was a reduction by 6.8% and 7.9%, respectively, in comparison with 3D. Similarly, the mean dose and V₂₀ for the ipsilateral lung and the percentage of volume of contralateral volume lung receiving > 5% of prescribed dose with IMRT were reduced by 9.9%, 2.2%, and 35%, respectively. The mean of total monitor units used for IMRT and 3DCRT was about the same (397 vs. 387). The tangential field IMRT for intact breast using sliding window technique was successfully implemented in the clinic. We have now treated more than 1000 breast cancer patients with this technique. The dosimetric data suggest improved dose homogeneity in the breast and reduction in the dose to lung and heart for IMRT treatments, which may be of clinical value in potentially contributing to improved cosmetic results and reduced late treatment-related toxicity.     

Clinical Implementation of Tangential Field Intensity Modulated Radiation Therapy (IMRT) Using Sliding Window Technique and Dosimetric Comparison with 3D Conformal Therapy (3DCRT) in Breast Cancer

The purpose of this study was to evaluate the clinical implementation of tangential field IMRT using sliding window technique and to compare dosimetric parameters with 3-dimensional conformal radiation therapy (3DCRT). Twenty breast cancer patients were randomly selected for comparison of intensity modulated radiation therapy (IMRT)-based treatment plan with 3DCRT. Inverse treatment was performed using the sliding window technique, employing the Eclipse^® Planning System (version 7.1.59, Varian, Palo Alto, CA). The dosimetric parameters compared were V₉₅ (the percentage of target volume getting ≥95% of prescribed dose), V₁₀₅, V₁₁₀, and dose homogeneity index, DHI (percentage of target volume getting between 95% and 110% of prescribed dose). The mean V₉₅, DHI, V₁₀₅, and V₁₁₀ for target volume for IMRT vs. 3D were 90.6% (standard deviation [SD]: 3.2) vs. 91% (SD: 3.0), 87.7 (SD: 6.0) vs. 82.6 (SD: 7.8), 27.3% (SD: 20.3) vs. 49.4% (SD: 14.3), and 2.8 (SD: 5.6) vs. 8.4% (SD: 7.4), respectively. DHI was increased by 6.3% with IMRT compared to 3DCRT (p < 0.05). The reductions of V₁₀₅ and V₁₁₀ for the IMRT compared to 3DCRT were 44.7% and 66.3%, respectively (p < 0.01). The mean dose and V₃₀ for heart with IMRT were 2.3 (SD: 1.1) and 1.05 (SD: 1.5) respectively, which was a reduction by 6.8% and 7.9%, respectively, in comparison with 3D. Similarly, the mean dose and V₂₀ for the ipsilateral lung and the percentage of volume of contralateral volume lung receiving > 5% of prescribed dose with IMRT were reduced by 9.9%, 2.2%, and 35%, respectively. The mean of total monitor units used for IMRT and 3DCRT was about the same (397 vs. 387). The tangential field IMRT for intact breast using sliding window technique was successfully implemented in the clinic. We have now treated more than 1000 breast cancer patients with this technique. The dosimetric data suggest improved dose homogeneity in the breast and reduction in the dose to lung and heart for IMRT treatments, which may be of clinical value in potentially contributing to improved cosmetic results and reduced late treatment-related toxicity.     

Effect of superparamagnetic iron oxide on tumor‐to‐liver contrast at T2*‐weighted gradient‐echo MRI: Comparison between 3.0T and 1.5T MR systems

Purpose

To compare 3.0T and 1.5T MR systems in terms of the effect of superparamagnetic iron oxide (SPIO) on tumor‐to‐liver contrast in T2*‐weighted gradient‐echo MRI.

Materials and Methods

SPIO‐enhanced gradient‐echo MR images of the liver with four different TEs (3, 5.3, 6.5, and 8.5 msec) were obtained by means of 1.5T and 3.0T systems. Quantitative analyses of relative signal intensities (SIs) and relative tumor contrast and qualitative analyses of image quality and lesion conspicuity of the liver were performed in 22 patients, 16 of whom had malignant liver tumors.

Results

With both 1.5T and 3.0T, at TE = 8.4 msec, the relative SI of liver and relative tumor contrast were significantly (P < 0.01) lower and higher, respectively, than that for any of the other TEs. There were no significant differences in the relative SI of the liver, relative tumor contrast, image quality, and tumor conspicuity for the same TE between the 1.5T and 3.0T systems.

Conclusion

Our results showed that the effect of SPIO on tumor‐to‐liver contrast at T2*‐weighted gradient‐echo imaging was similar for the 1.5T and 3.0T systems, and that the 8.4‐msec TE was optimal of the four TEs used in this study at 3.0T. J. Magn. Reson. Imaging 2009;29:595–600. © 2009 Wiley‐Liss, Inc.