妇科肿瘤后装逆向调强放疗的初步临床研究

目的 评价后装逆向调强放疗技术在妇科肿瘤治疗中的临床价值。方法 选取20例Ⅰ~Ⅲ期宫颈癌患者,采用随机数字表和余数分组的方法分为A、B两组,各10例。A组病例行后装逆向调强放疗,B组病例行三维适形后装放疗。分析两组患者的靶区剂量分布、危及器官受量、放疗并发症及近期疗效。 结果 A组靶区剂量均匀度指数（HI）为52.43±0.45,好于B组的46.37±1.45（t=0.92,P<0.05）;A组直肠、膀胱最大受量D_max分别比B组低37%、35%（t=1.34、1.39,P<0.05）,A组75%处方剂量的直肠、膀胱受照体积V₇₅约为B组的1/2（t=1.23、1.13,P<0.05）;A组局部控制率96%好于B组的 93%（t=1.25,P<0.05）。结论 后装逆向调强放疗优于三维适形后装放疗,值得在妇科肿瘤治疗中广泛应用。     

18F-氟脱氧葡萄糖PET监测实体瘤放化疗疗效的应用进展

利用18^F-氟脱氧葡萄糖（18^F—FDG）PET监测肿瘤放疗或化疗的疗效以及区分残余或复发病灶已广泛用于临床。18^F-FDG PET定量分析肿瘤在治疗开始时的变化可以预测肿瘤对治疗的反应性及患者的预后，并可根据肿瘤的反应性调整治疗方案。利用18^F-FDG PET早期预测肿瘤对放、化疗的反应性，在个体化治疗方案的制定、减少无效治疗所带来的副作用等方面有着巨大的潜能。     

Therapy monitoring using dynamic MRI: Analysis of lung motion and intrathoracic tumor mobility before and after radiotherapy

A frequent side effect after radiotherapy of lung tumors is a decrease of pulmonary function accompanied by dyspnea due to developing lung fibrosis. The aim of this study was to monitor lung motion as a correlate of pulmonary function and intrathoracic tumor mobility before and after radiotherapy (RT) using dynamic MRI (dMRI). Thirty-five patients with stage I non-small-cell lung carcinoma were examined using dMRI (trueFISP; three images/s). Tumors were divided into T1 and T2 tumors of the upper, middle and lower lung region (LR). Maximum craniocaudal (CC) lung dimensions and tumor mobility in three dimensions were monitored. Vital capacity (VC) was measured and correlated using spirometry. Before RT, the maximum CC motion of the tumor-bearing hemithorax was 5.2±0.9 cm if the tumor was located in the lower LR (middle LR: 5.5±0.8 cm; upper LR: 6.0±0.6 cm). After RT, lung motion was significantly reduced in the lower LR (P<0.05). Before RT, the maximum CC tumor mobility was significantly higher in tumors of the lower LR 2.5±0.6 vs. 2.0±0.3 cm (middle LR; P<0.05) vs. 0.7±0.2 cm (upper LR; P<0.01). After RT, tumor mobility was significantly reduced in the lower LR (P<0.01) and in T2 tumor patients (P<0.05). VC showed no significant changes. dMRI is capable of monitoring changes in lung motion that were not suspected from spirometry. This might make the treatment of side effects possible at a very early stage. Changes of lung motion and tumor mobility are highly dependent on the tumor localization and tumor diameter.     

糖尿病合并肿瘤患者进行放射治疗的观察及护理

糖尿病合并肿瘤患者的放射治疗可以破坏或消灭肿瘤细胞,同时也可损伤正常的组织与细胞,引起各种急性、慢性副作用.急性副作用在治疗后不久随即出现,并且在治疗停止后几周内完全消失,慢性副作用可能需要几月或几年才逐渐显现出来。因此,做好放疗期的观察与护理,可以减轻病人的痛苦,控制血糖,保持心理平衡,提高放疗效果。1临床资料本组收集糖尿病合并恶性肿瘤患者21例,其中男17例,女4例,年龄59~72岁,平均年龄67岁。肺癌13例,骨转移瘤4例,乳腺癌2例,肝癌1例,肾癌1例。2结果经放射治疗好转出院20例,死亡1例。其中临床表现症状为继发各种感染10例…     

肿瘤放射治疗的免疫效应

近些年,免疫学者已注意到电离辐射对肿瘤免疫的效应,并试图探讨其诱导和改善抗肿瘤免疫效应。越来越多的证据表明,采用确切的放疗方案和有效的照射剂量,特别是与免疫治疗联合应用,能够诱导或调节全身免疫反应,有助于肿瘤的控制或炎性反应的发生。本文综述放疗对肿瘤免疫效应及其机制,以及与免疫治疗联合应用效果,以期指导肿瘤放疗与免疫治疗的有效联合应用。     

The effect of paclitaxel on the radiosensitivity of gynecological tumor cells

Background

Paclitaxel, a natural product from Taxus brevifolia, is a microtubule stabilizing agent, which has been shown to block different cells in the G2/M phase of the cell cycle and consequently, to modulate their radioresponsiveness. Our aim was to test the cytotoxic and radiosensitizing potential of paclitaxel, with respect to different gynecological tumors with varying radiosensitivities.

Material and Method

We performed clonogenic assays and flow cytometry on 2 cell lines, MCF-7 (breast) and CaSki (cervix) cells, and on 2 primary ovarian tumor samples (OC-I and OC-II). The cells were irradiated with 200 kV X-rays, radiation doses of up to 8 Gy were applied either as single doses or in 2 Gy fractions. Paclitaxel concentrations varied from 0.07 to 700 nM, incubation times varied from 3 to 120 h.

Results

Paclitaxel alone changed the cell cycle distribution of the cells tested and was cytotoxic in a time and concentration dependent manner. When combined with radiation, most schedules resulted in additive effects of the combined treatments. However, for MCF-7 cells, when 7 nM paclitaxel, applied 24 h before irradiation, were combined with fractionated irradiation a supra-additive effect with a SER of 1.2 was found. For CaSki cells, under comparable conditions the SER was 1.13 but the effects were not statistically significant.

Conclusion

Under specific conditions, paclitaxel exerted a weak radiosensitizing effect on breast and cervical carcinoma cells. A therapeutic gain may be possible on the basis of an optimal paclitaxel/radiation scheduling.     

Comparison of SUV and Patlak slope for monitoring of cancer therapy using serial PET scans

The standardized uptake value (SUV) and the slope of the Patlak plot ( K) have both been proposed as indices to monitor the progress of disease during cancer therapy. Although a good correlation has been reported between SUV and K, they are not equivalent, and may not be equally affected by metabolic changes occurring during disease progression or therapy. We wished to compare changes in tumor SUV with changes in K during serial positron emission tomography (PET) scans for monitoring therapy. Thirteen patients enrolled in a protocol to treat renal cell carcinoma metastases were studied. Serial dynamic fluorodeoxyglucose (FDG) PET scans and computed tomography (CT) and magnetic resonance (MR) scans were performed once prior to treatment, once at 36+/-2 days after the start of treatment, and (in 7/13 subjects, 16/27 lesions) a third time at 92+/-9 days after the start of treatment. This resulted in a total of 33 scans, and 70 tumor Patlak and SUV values (one value for each lesion at each time point). SUV and K were measured over one to four predefined tumors/patient at each time point. The input function was obtained from regions of interest over the heart, combined, if necessary, with late blood samples. Over all tumors and scans, SUV and K correlated well ( r=0.97, P<0.0001). However, change in SUV with treatment over all tumor scan pairs was much less well correlated with the corresponding change in K ( r=0.73, P<0.0001). The absolute difference in % change was outside the 95% confidence limits expected from previous variability studies in 6 of 43 pairs of tumor scans, and greater than 50% in 2 of 43 tumor scan pairs. In four of the six cases, the two indices predicted opposing therapeutic outcomes. Similar results were obtained for SUV normalized by body weight or body surface area and for SUVs using mean or maximum count. Changes in CT and MR tumor cross-product dimensions correlated poorly with each other ( r=0.47, P=NS), and so could not be used to determine the "correct" PET index. Absolute values of SUV and K correlated well over the patient population. However, when monitoring individual patient therapy serially, large differences in the % changes in the two indices were occasionally found, sometimes sufficient to produce opposing conclusions regarding the progression of disease.     

纳米金在肿瘤显像与放射治疗中的应用

纳米金因具有良好的表面性质和优异的生物亲和性,使其能被多种基团修饰,从而获得对肿瘤细胞的靶向性;又因其具有表面等离子共振效应等强吸收和发光特性,故可进行肿瘤显像.另外,在肿瘤放疗过程中,纳米金能够将吸收的光能转化为热能进行肿瘤局部加热,起到了放疗增敏的效果,从而减少受照剂量,减轻放疗对正常组织的伤害.该文阐述靶向修饰的...     

放射治疗中肿瘤控制概率的计算方法

肿瘤控制概率(TCP)是评估放射治疗效果的重要参数,多年来,很多学者在考虑不同影响因素的情况下提出了各种计算公式,并对用这些公式计算的TCP值与临床实际统计值之间的差距进行了分析。     

放射治疗中肿瘤控制概率的影响因素

可靠的肿瘤控制概率计算模型是对放射治疗方案进行准确评估的基础。所以,对肿瘤控制概率模型中所涉及的参数及对这些参数取值有影响的因素进行总结有利于提出更完善的计算模型。     

Dosimetric evaluation of MLC-based dynamic tumor tracking radiotherapy using digital phantom: Desired setup margin for tracking radiotherapy

The purpose of this study is to evaluate the dosimetric impact of the margin on the multileaf collimator-based dynamic tumor tracking plan. Furthermore, an equivalent setup margin (EM) of the tracking plan was determined according to the gated plan. A 4-dimensional extended cardiac-torso was used to create 9 digital phantom datasets of different tumor diameters (TDs) of 1, 3, and 5?cm and motion ranges (MRs) of 1, 2, and 3?cm. For each dataset, respiratory gating (30% to 70% phase) and tumor tracking treatment plans were prepared using 8-field 3-dimensional conformal radiation therapy by 4-dimensional dose calculation. The total lung V20 was calculated to evaluate the dosimetric impact for each case and to estimate the EM with the same impact on lung V20 obtained with the gating plan with a setup margin of 5?mm. The EMs for {TD?=?1?cm, MR?=?1?cm}, {TD?=?1?cm, MR?=?2?cm}, and {TD?=?1?cm, MR?=?3?cm} were estimated as 5.00, 4.16, and 4.24?mm, respectively. The EMs for {TD?=?5?cm, MR?=?1?cm}, {TD?=?5?cm, MR?=?2?cm}, and {TD?=?5?cm, MR?=?3?cm} were estimated as 4.24?mm, 6.35?mm, and 7.49?mm, respectively. This result showed that with a larger MR, the EM was found to be increased. In addition, with a larger TD, the EM became smaller. Our result showing the EMs provided the desired accuracy for multileaf collimator-based dynamic tumor tracking radiotherapy.     

颅脑肿瘤放射治疗时射野外器官吸收剂量体模法测量与分析

目的 在是否使用楔形板和照射野面积不同的情况下,测量和分析颅脑肿瘤放射治疗时射野外器官的吸收剂量。 方法 使用中国成人男性仿真人体模型,模拟颅脑肿瘤放射治疗,采用不使用楔形板的普通方野照射技术组和使用楔形板的三维适形照射技术（3D-CRT）组,普通方野照射技术组分别用2 cm×2 cm野和4 cm×4 cm野进行照射,3D-CRT组分别按等效方野面积分为2 cm×2 cm野和4 cm×4 cm野进行照射;使用热释光剂量计测量射野外器官的吸收剂量并进行分析。 结果 颅脑肿瘤靶区处方剂量为100 cGy时,射野外各器官吸收剂量范围为0.13~2.83 mGy。头颈部器官4 cm×4 cm野照射时的吸收剂量与2 cm×2 cm野比较,差异有统计学意义（t=-5.023,P=0.004）;胸腹部器官4 cm×4 cm野照射时的吸收剂量与2 cm×2 cm野比较,差异无统计学意义（t=-1.438,P=0.171）。普通方野照射组头颈部器官、腹部器官的吸收剂量与3D-CRT组比较,差异均有统计学意义（t头=-2.805,P=0.038;t腹=-11.966,P=0.000）。 结论 接受颅脑肿瘤放射治疗的患者,射野外器官吸收剂量的大小与照射野面积、是否采用楔形板照射技术有关。接受大野照射的患者,靶区邻近器官吸收剂量越大;照射野面积和处方剂量相同时,使用楔形板的照射技术相对于不使用楔形板的射野外器官的吸收剂量增大。