Dosimetric Characteristics of the Siemens IGRT Carbon Fiber Tabletop

In this work, the dosimetric characteristics of a new commercial carbon fiber treatment table are investigated. The photon beam attenuation properties of the Siemens image-guided radiation therapy (IGRT) tabletop were studied in detail. Two sets of dosimetric measurements were performed. In the first experiment a polystyrene slab phantom was used: the central axis attenuation and the skin-sparing detriment were investigated. In the second experiment, the off-axis treatment table transmission was investigated using a polystyrene cylindrical phantom. Measurements were taken at the isocenter for a 360° rotation of the radiation beam. Our results show that the photon beam attenuation of the Siemens IGRT carbon fiber tabletop varies from a minimum of 2.1% (central axis) to a maximum of 4.6% (120° and 240° beam incidence). The beam entrance dose increases from 82% to 97% of the dose at the depth of maximum for a clinical 6-MV radiation field. The depth of maximum also decreases by 0.4 cm. Despite the wedge cross section of the table the beam attenuation properties of the IGRT tabletop remain constant along the longitudinal direction. American Association of Medical Dosimetrists.     

个体患者适形调强放疗计划模体内剂量实测验证技术的建立

目的建立个体患者适形调强放疗（IMRT）计划的模体内剂量实测验证技术。方法选择1例鼻咽癌患者，设计IMRT计划。将患者计划转移到模体上设计杂交计划。执行杂交计划时，用针点电离室测量感兴趣点的剂量，并与该点的计算剂量比较。用胶片剂量测量系统测量杂交计划中感兴趣平面的剂量，胶片与计划剂量矩阵登记后，依次进行计划，胶片分析、计划，胶片剖面分析和计划／胶片等剂量线分析。采用复合判断标准评价验证结果。结果针点电离室测量得到杂交计划单次照射的总剂量为121．5cGy，比计算值低约4％。计划，胶片分析得到高剂量、高梯度区域的距离差别均在4mm以内；计划／胶片剖面分析显示，计划与胶片在通过靶区的剖面具有较好的一致性；计划，胶片等剂量线分析显示，计划与胶片对应值的等剂量线重合良好。按照复合判断标准，该计划验证通过。结论初步建立了个体患者IMRT计划的模体内剂量实测验证技术，建立并优化了剂量登记技术、剂量归一方法和评价方法。     

A surveillance study of patterns of reirradiation practice using external beam radiotherapy in Japan

The aim of this study was to survey the present status and patterns of reirradiation (Re-RT) practice using external beam radiotherapy in Japan. We distributed an e-mail questionnaire to the Japanese Society for Radiation Oncology partner institutions, which consisted of part 1 (number of Re-RT cases in 2008–2012 and 2013–2018) and part 2 (indications and treatment planning for Re-RT and eight case scenarios). Of the 85 institutions that replied to part 1, 75 (88%) performed Re-RTs. However, 59 of these 75 institutions (79%) reported difficulty in obtaining Re-RT case information from their databases. The responses from 37 institutions included the number of Re-RT cases, which totaled 508 in the period from 2009 to 2013 (institution median 3; 0–235), and an increase to 762 cases in the period from 2014 to 2018 (12.5; 0–295). A total of 47 physicians responded to part 2 of the survey. Important indications for Re-RT that were considered were age, performance status, life expectancy, absence of distant metastases and time interval since previous radiotherapy. In addition to clinical decision-making factors, previous total radiation dose, volume of irradiated tissue and the biologically equivalent dose were considered during Re-RT planning. From the eight site-specific scenarios presented to the respondents, >60% of radiation oncologists agreed to perform Re-RT. Re-RT cases have increased in number, and interest in Re-RT among radiation oncologists has increased recently due to advances in technology. However, several problems exist that emphasize the need for consensus building and the establishment of guidelines for practice and prospective evaluation.     

心电图机应用过程中的质量保证

心电图机应用过程中的质量保证对其向临床提供准确可信的测量参数和诊断结果具有重要意义。在多年实践摸索和理论分析的基础上，本文从心电图机使用前的条件准备、心电描记过程中的质量控制、日常的维护保养以及计量检测等环节人手，研究并提出了一套规范的质量保证方案，以确保心电检查数据的准确性和临床心电诊断的质量。     

Comparison of intensity-modulated radiotherapy with the 5-field technique,helical tomotherapy and volumetric modulated arc therapy for localized prostate cancer

The outcomes of three methods of intensity-modulated radiation therapy (IMRT) for localized prostate cancer were evaluated. Between 2010 and 2018, 308 D’Amico intermediate- or high-risk patients were treated with 2.2 Gy daily fractions to a total dose of 74.8 Gy in combination with hormonal therapy. Overall, 165 patients were treated with 5-field IMRT using a sliding window technique, 66 were then treated with helical tomotherapy and 77 were treated with volumetric modulated arc therapy (VMAT). The median age of patients was 71 years. The median follow-up period was 75 months. Five-year overall survival (OS) and biochemical or clinical failure-free survival (FFS) rates were 95.5 and 91.6% in the 5-field IMRT group, 95.1 and 90.3% in the tomotherapy group and 93.0 and 88.6% in the VMAT group, respectively, with no significant differences among the three groups. The 5-year cumulative incidence of late grade ≥2 genitourinary and gastrointestinal toxicities were 7.3 and 6.2%, respectively, for all patients. Late grade ≥2 gastrointestinal toxicities were less frequent in patients undergoing VMAT (0%) than in patients undergoing 5-field IMRT (7.3%) and those undergoing tomotherapy (11%) (P = 0.025), and this finding appeared to be correlated with the better rectal DVH parameters in patients undergoing VMAT. Other toxicities did not differ significantly among the three groups, although bladder dose-volume parameters were slightly worse in the tomotherapy group than in the other groups. Despite differences in the IMRT delivery methods, X-ray energies and daily registration methods, all modalities may be used as IMRT for localized prostate cancer.     

质量保证在长期毒性试验原始资料核查中的关注点

本文论述了质量保证(QA)在长期毒性试验原始资料核查过程中的关注点和主要问题,包括方案、报告和原始记录的一致性、原始资料记录的规范性和准确性、数据核查和资料保存等。分析问题产生的原因,主要归结于GLP意识不强、GLP依从性和SOP的执行力差。对减少问题发生提出了建议和措施,包括加强GLP培训、提高对GLP和SOP的依从性、计算机化仪器系统的运用和专家对GLP单位实施飞行检查等。     

18F-FDG PET-CT功能影像引导下鼻咽癌同步加速生物调强放疗疗效分析

目的 目前,局部晚期鼻咽癌的治疗效果欠佳,多种不同的放疗技术已应用于鼻咽癌的治疗以提高其疗效.本研究采用18 F-FDG PET-CT功能影像引导同步加速生物调强放疗技术(simultaneous modulated accelerated biological radiation therapy,SMABRT)治疗鼻咽癌,探讨其疗效及安全性.方法 选取2007-06-01-2011-12-05采用GE Discovery ST_8 PET-CT进行模拟定位,显像药物为放射性核素18F标记的FDG,采用视觉分辨法勾画鼻咽肿瘤代谢活性高聚区并定义为GTVnx.pet,中位剂量78 Gy(68.5～81.6 Gy),2.18～2.47 Gy/次,根据CT、MRI或电子鼻咽喉镜所示肿瘤范围勾画大体肿瘤靶区GTVnx,中位剂量74.6 Gy(67～80.4 Gy),2.03～2.44 Gy/次;颈部肿大淋巴结GTVnd中位剂量72 Gy(60～78.5 Gy),1.82～2.38 Gy/次;CTV1剂量60 Gy,1.82 Gy/次;CTV2剂量54～56 Gy,1.64～1.70 Gy/次.结果 中位随访时间56.63个月(1.90～90.97个月).全组4年总生存率(overall survival,OS)、无局部区域复发生存率(local regional recurrence-free survivaal,LRRFS)、无远处转移生存率(distant metastasis-free survival,DMFS)分别为83％、93％和86％.Ⅰ、Ⅱ、Ⅲ和ⅣA期4年OS分别为100％、100％、88％和67％(x2=7.710,P=0.052),LFFRS分别为100％ 、86％ 、92％和97％(x2=1.928,P=0.587),DMFS分别为100％、100％、95％和65％(x2 =14.079,P=0.003).GTVnx.pet低剂量组(≤77 Gy)和高剂量组(＞77 Gy)4年OS、LRRFS和DMFS分别为82％和83％(x 2=0.005,P=0.948)、80％和97％(x2 =5.569,P=0.018)、97％和81％(x2 =3.598,P=0.058).多因素分析显示,LRRFS的独立预后因素为GTVnx.pet照射剂量,DMFS的独立预后因素为总分期,OS的独立预后因素为N分期.全组患者未发生≥3级晚期放射性损伤.结论 采用18 F-FDG PET-CT功能影像引导下SMABRT治疗鼻咽癌,当给予肿瘤代谢活跃区较高的照射剂量时,能提高局部晚期鼻咽癌的局部区域控制率,各分期之间LRRFS无显著差异,不增加正常组织晚反应损伤,肿瘤代谢活跃区的照射剂量为影响LRRFS的唯一因素,总生存及无远处转移生存未见明显改善.     

食管癌术后纵隔各分区的淋巴结转移概率研究

目的：分析各段食管癌术后局部复发模式,探讨食管癌术后辅助性调强放疗的靶区勾画技巧,缩小照射野,降低放疗毒副作用.方法：收集589例接受根治性切除的食管癌患者临床资料.其中术后复发157例,淋巴结复发83.4％（131例）,瘤床复发9.6％（15例,包括合并淋巴结复发6例）,吻合口复发5.7％（9例,包括合并淋巴结复发4例,合并残胃复发1例）,残胃复发1.3％（2例）.结果：各段食管癌术后的复发模式以区域淋巴结转移为主,食管癌淋巴结复发仍以纵隔淋巴结转移为主,纵隔1R区淋巴结复发明显高于其他分区,并且没有纵隔5区淋巴结复发.贲门癌以腹腔淋巴结复发为主;T4、T3、T2期患者手术后瘤床复发的风险分别为19.1％、1.4％、1.5％,瘤床复发主要为T4期患者.结论：临床上做食管癌术后辅助性调强放疗时,CTV可以根据不同部位食管癌的复发模式及淋巴结转移规律进一步缩小照射野.食管癌根治术后放疗靶区应设计为：上段食管癌应包括双锁骨上,纵隔1、2、4、7、3P区,瘤床,吻合口;中、下段食管癌术后放疗靶区包括双锁骨上,纵隔1、2、4、7、3P区,吻合口.T4期患者包括瘤床即可,瘤床下界置于原发灶下界即可.T3以上患者由于瘤床复发几率很低,可甩掉瘤床的照射.对于术后清扫贲门或胃左淋巴结阳性的患者可照射腹腔淋巴结引流区,包括腹腔3、7、8、9、16a组淋巴引流区;贲门癌包括瘤床,腹腔33、8、9、10、11、16a组淋巴引流区.     

榄香烯注射液联合单药长春瑞滨同步调强放疗治疗老年中晚期食管鳞癌的近期疗效

目的：观察榄香烯注射液联合单药长春瑞滨同步调强放疗治疗老年中晚期食管鳞癌的近期疗效和不良反应。方法80例老年食管鳞癌患者随机分为单纯调强放疗组（简称单放组）和榄香烯注射液联合单药长春瑞滨同步调强放疗组（联合组）,每组各40例病人。两组患者调强放射治疗方法相同,放疗总剂量60~66 Gy。联合组每日放疗前2 h 予榄香烯200 mg 加入5%葡萄糖溶液100 ml 静脉滴注,长春瑞滨（ NVB）25 mg/m2,第1、8天,21天为一个周期,同步放疗连续化疗2周期。结果联合组患者近期有效率为92.5%,明显高于单放组的75%（P ﹤0.05）,两组不良反应发生率无显著性差异。结论对于老年中晚期食管鳞癌患者,可采用榄香烯注射液联合单药长春瑞滨同步调强放疗的治疗方法,有较好的近期疗效,不良反应并未明显增加,远期疗效需进一步观察。