肺癌放疗中的呼吸运动问题及解决方法

呼吸运动是影响肺癌放疗效果的重要因素，同时它也是一个比较复杂和难于解决的问题。笔者将从呼吸运动过程中肺肿瘤的运动情况、呼吸运动对肺癌放疗的剂量学影响、肺癌放疗中呼吸运动问题的解决方法等方面来阐述肺癌放疗中的呼吸运动问题及解决方法。     

超声诊断急性阑尾炎的临床价值

目的:探讨超声诊断急性阑尾炎的临床价值。方法:回顾性分析经临床手术证实60例阑尾炎患者的超声资料。结果:病理诊断单纯性阑尾炎15例,化脓性阑尾炎36例,坏疽性阑尾炎7例,阑尾周围脓肿2例。结论:急性阑尾炎具有较典型的超声声像图特征,可以确诊并做出粗略的病理分型。     

近距离治疗中^192Ir放射源的校准

叙述以参考空气比释动能率校准１９２Ｉｒ高剂量率放射源的刻度方法及对结果的分析。材料与方法使用ＮＥ０．６ｃｃ２５７１型石墨电离室和自行设计的测量支架。电离室及剂量仪经国家计量科学院校准，由于目前尚无１９２Ｉｒ刻度标准，一般对６０Ｃｏγ和２５０ＫＶＸ射线插值，以获得１９２Ｉｒ的校准因子。这一方法要求电离室具有较好的能响特性（１．０－２．０％），以及校准时有相同的室壁厚度。结果分别在１０ｃｍ和１５ｃｍ处刻度１９２Ｉｒ放射源，所得结果的差别小于１．０％。结论这一方法的系统误差，主要来自插值以获得１９２Ｉｒ的校准因子，由于使用的电离室能响较好及方法得当，插值的误差不会超过０．５％，而其他因子相对较小，对系统误差不会有较大影响，因此可以认为以参考空气比释动能率刻度１９２Ｉｒ剂量率的方法准确可行。     

彩色多普勒诊断原发性肝癌并门静脉癌栓

目的：探讨原发性肝癌合并门静脉癌栓的彩色多普勒特点及诊断价值。方法：应用Philips HDII彩色超声诊断仪对34例原发性肝癌合并门静脉癌栓的血流特征进行回顾性分析。结果：根据门静脉癌栓内部及周边血流信号的彩色多普勒状况,分为4种情况：①癌栓内无血流信号;②癌栓内有少许血流信号;③门静脉癌栓周围出现动静脉瘘;④癌栓与管壁之间出现动脉血流。结论：原发性肝癌合并门静脉癌栓有其门静脉及肝动脉血流动力学的特殊变化,对区分原发性肝癌和继发性肝癌有较重要的临床价值。     

经阴道超声对输卵管脓肿的诊断价值

目的:探讨输卵管脓肿的经阴道超声声像图特征及其诊断价值.方法:回顾性分析53例输卵管脓肿患者的经阴道超声图像,其中48例经手术病理证实为输卵管脓肿.结果:48例患者超声诊断正确,其中一侧输卵管积脓19例,双侧积脓29例.77个输卵管积脓包块呈纡曲管状、腊肠状或曲颈瓶状无回声区,其中71个输卵管管壁有不完全分隔回声,68...     

超声诊断20例腹膜后肿块与病理结果对照分析

本文报告20例经手术和病理证实的腹膜后肿块的超声检查结果，探讨其声像图特征与病理的关系，并对超声误诊的病例进行分析，以利于提高我们的诊断水平。     

彩色多普勒超声对胆囊隆起性病变的诊断价值

目的 探讨彩色多普勒超声对胆囊隆起性病变的鉴别诊断价值。方法 对236例病灶大于0．6cm的胆囊隆起性病变,应用彩色多普勒超声检查,从不同方位、不同角度多切面观察病灶处彩色血流信号,检测血流频谱。结果 胆囊腺癌病灶内均可检测到动脉血流信号,而胆囊腺肌症、胆固醇息肉、炎性息肉病灶内均未检测到血流信号。15例胆囊腺瘤中仅1例检测到动脉血流信号,其RI值明显低于胆囊癌。结论 彩色多普勒超声检查有助于对胆囊隆起性病变性质的鉴别,特别是较大的腺瘤与早期胆囊癌的鉴别,弥补了常规二维超声检查的不足。     

呼吸运动对肺部肿瘤靶区受照剂量分布影响的研究

Objective To investigate the influence of respiratory motion on target dose distribution in radiotherapy for patients with lung tumors. Methods The Big Bore Brilliance CT with bellows system was used to gain the 4DCT sets and respiratory frequency information of the patients. The moving ranges of the tumors in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) directions were measured from the center coordinate values of gross tumor volume of ten time-phase CT sets in the treatment planning sys-tem. Then a breathing model was used to simulate the tumor motions due to respiration. A 4-dimensional motion table was used to mimic the motion of lung tumor in beams-eye-view (BEV). A 2-dimensional semi-conductor beams measurement system was fixed to the table to measure the 2-dimensional dose distribution of static and dynamic targets using the treatment beams at gantry angle of 0°. Finally, the differences of the dose distribution between the static and moving phantom were compared and analyzed with the statistical soft-ware R. Results When the amplitude (half of the moving rang) in the CC direction was 1 cm, the passing ratio of relative dose difference ≤4% in one beam field was minimal (1.1%), and there was 58% maximal relative dose absence. The 4% passing ratios media in the CC direction were 94.7%, 79.4%, 58.6% and 37.1% in <0.25, 0.25-<0.50, 0.50- <0.75 and ≥0.75 mm amplitude (X<'2>=29.20,P=0.000), but were all similar in the AP and LR directions. The mean value of the relative dose change in the high dose area was smaller than the low dose area in the 89% beam fields. When only the CC direction was consid-ered, the 4% passing ratio of 3.6 s and 8.2 s period was 72% and 60%, respectively. Conclusions The amplitude in the CC direction is a factor impacting the dose distribution of the moving target. The influence of respiratory motion on high dose area is more than that on low dose area. When the other respiratory param-eters are fixed, the motion of long period has more influence on the dose than that of short period. Special at-tention should be paid to the patients with tumor of more than 0.5 cm amplitude in the CC direction when planning the intensity modulated radiotherapy.     

鼻咽癌半束照射的剂量分布

目的 比较鼻咽癌半束和全束照射技术射野衔接处的剂量分布以及脑和肺的受量。方法 应用Varian 600CD直线加速器，在固体水模体中采用胶片黑度法测量鼻咽癌面颈联合野和下颈切线野射野衔接处的剂量分布。应用Helax TMS-3D治疗计划系统，根据实际病例的螺旋CT模拟定位资料，在数字重建图像上设计面颈联合野和下颈切线野，分别计算半束和全束照射技术条件下脑组织和肺的受量，比较两者受照射的剂量体积直方图(DVH)及脑组织受照射的最大剂量、最小剂量、中位剂量、平均剂量、25％受较高照射剂量脑组织的下限剂量(D25％)以及受量超过75％肿瘤剂量的脑体积(V75%)。结果 两种照射技术射野衔接处均无漏照及低剂量区情况，半束照射和全束共线照射分别有约4mm、10mm的剂量重叠区，两野衔接处剂量最高点高出剂量归一点分别为28％和117％。两种照射技术脑及肺受照射的DVH相似，脑受照射的最小剂量、最大剂量、中位剂量、平均剂量、D25％、V75％及破裂孔处剂量均以全束照射略高，但相差幅度均不超过1％。结论 鼻咽癌应用面颈联合野和下颈切线野放射治疗时，与全束照射技术相比，半束照射技术照射野衔接处的剂量重叠区较小，脑和肺的照射体积和剂量没有增加。     

呼吸运动对肺部肿瘤靶区受照剂量分布影响的研究

Objective To investigate the influence of respiratory motion on target dose distribution in radiotherapy for patients with lung tumors. Methods The Big Bore Brilliance CT with bellows system was used to gain the 4DCT sets and respiratory frequency information of the patients. The moving ranges of the tumors in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) directions were measured from the center coordinate values of gross tumor volume of ten time-phase CT sets in the treatment planning sys-tem. Then a breathing model was used to simulate the tumor motions due to respiration. A 4-dimensional motion table was used to mimic the motion of lung tumor in beams-eye-view (BEV). A 2-dimensional semi-conductor beams measurement system was fixed to the table to measure the 2-dimensional dose distribution of static and dynamic targets using the treatment beams at gantry angle of 0°. Finally, the differences of the dose distribution between the static and moving phantom were compared and analyzed with the statistical soft-ware R. Results When the amplitude (half of the moving rang) in the CC direction was 1 cm, the passing ratio of relative dose difference ≤4% in one beam field was minimal (1.1%), and there was 58% maximal relative dose absence. The 4% passing ratios media in the CC direction were 94.7%, 79.4%, 58.6% and 37.1% in <0.25, 0.25-<0.50, 0.50- <0.75 and ≥0.75 mm amplitude (X<'2>=29.20,P=0.000), but were all similar in the AP and LR directions. The mean value of the relative dose change in the high dose area was smaller than the low dose area in the 89% beam fields. When only the CC direction was consid-ered, the 4% passing ratio of 3.6 s and 8.2 s period was 72% and 60%, respectively. Conclusions The amplitude in the CC direction is a factor impacting the dose distribution of the moving target. The influence of respiratory motion on high dose area is more than that on low dose area. When the other respiratory param-eters are fixed, the motion of long period has more influence on the dose than that of short period. Special at-tention should be paid to the patients with tumor of more than 0.5 cm amplitude in the CC direction when planning the intensity modulated radiotherapy.