术中实时剂量学优化在放射性粒子植入治疗脑胶质瘤中的价值研究

目的探讨术中实时剂量学优化在125I放射性粒子植入治疗脑胶质瘤手术中价值。方法对8例患有恶性脑胶质瘤并行125I放射性粒子植入治疗的患者进行回顾性分析,术前计划和术后计划的验证,还要在术中进行了实时剂量学优化,对比分析两组病例剂量学评价指标的差异。记录两组患者术前及术后DVH图所示D90、m PD、PD、V90、V100、V150、V200、CI、EI、HI,比较组内术前及术后计划D90和m PD差异,同时对组间术后计划PD、V90、V100、V150、V200、CI、EI、HI进行比较,了解有无差别。其中,组内差异采用的统计学方法为配对t检验,组间差异的统计学方法采用独立样本t检验。结果 A组手术前后D90和m PD差异有统计学意义。B组手术前后D90和m PD差异无统计学意义。两组手术后V90、V100、CI、EI和HI差异有统计学意义。两组手术后PD、V150和V200差异无统计学意义。结论术中实时剂量学优化能够保证术前计划相对准确的实施,从而确保术后剂量学分布的更加合理。     

术中125I粒子植入治疗复发性脑胶质瘤的临床研究

目的探讨复发性脑胶质瘤术中mI粒子植入治疗的近期治疗效果及并发症。方法回顾性分析58例复发性脑胶质瘤患者资料,其中,23例患者行单纯手术,另外35例利用计算机三维治疗计划系统于术前或术中制定治疗计划,术中依据所制定的剂量,在肿瘤切除后的瘤床上植入mI粒子,处方剂量为140～188Gy。术后每2个月复查CT或MRI进行验证和质量评估,随访8～32个月,比较分析两组患者的肿瘤复发率、生存期及放射性并发症。结果单纯手术组中有20例复发,复发率为87．0％;有3例死于术后并发症。术中mI粒子植入治疗组中有23例复发,复发率为65．7％;有5例死于术后并发症,4例发生顽固性脑水肿,3例发生放射性脑坏死。术中“I粒子植入治疗组肿瘤复发时间f（97．5±15．3）周】明显长于单纯手术组【（62．5±13．6）周]（t=9．21,P〈0．05）,生存期[（60．3±7．1）周】亦明显长于单纯手术组[（43．1±5．5）周1（t=13．03,P〈0．05）。单因素变量分析结果显示,世界卫生组织肿瘤病理分级与肿瘤切除程度是影响患者生存率的独立因素。结论术中125I粒子植入治疗可降低脑胶质瘤的复发率,有效增加复发性脑胶质瘤患者的生存时间。     

碘-125放疗支架治疗晚期食管癌的疗效观察

食管癌是我国尤其是西北地区发病率较高的恶性疾病，由于早期症状不明显，发现时，大多已经是中晚期，失去了手术机会，而全身放疗、化疗对患者全身的组织器官损伤大，无法达到预期的治疗目的。近年来，随着内镜下狭窄扩张术、支架植入术及射频治疗术旧’的应用，大大提高了患者的生存质量，改善了患者的营养问题。但上述治疗都是姑息治疗，无法对癌症组织起到治疗作用。我们把碘-125粒子随支架一起植入到患者体内，可以通过局部放疗达到抑制癌组织快速增生的问题。以下是我科对16例失去手术机会的食管癌晚期患者使用安装碘-125粒子的放疗支架后的疗效观察。     

用于永久性植入的碘-125源的比较

碘 12 5种子源用于近距离治疗前列腺癌已有 10几年的历史 ,目前市场上供应的主要产品有 10余种。这些产品外观设计相似 ,但其内部结构及物理性质存在差别。现将这些种子的基本特征作一比较。一、剂量学特征美国近距离治疗协会放射性治疗委员会建议每种新的近距离治疗源在临床使用之前都应该进行详细的剂量学特征的测定。制造商应该至少 (最好是两种 )用一种独立的方法来完成测量并用蒙特卡罗模拟来证实其种源的剂量特征[1 ] 。所有种源的剂量特征都应该按照ＴＧ 43建议的方法来表述[2 ] 。然而现在还没有一个统一的测定标准来表征种源剂量特…     

食管癌125I粒子支架临床研究中文文献质量评价

目的 评估我国125I内照射支架治疗食管癌文献的质量.方法 按照循证医学标准,分别按不同年份对2010年6月前的不同设计类型文献的一般情况进行分类.由2名评阅者对文献进行质量评价,对评阅者的评价结果进行Kappa检验,检验结果的一致性.参照Jadad评分量表,计算随机对照试验(RCT)的Jadad得分,按照CONSOR...     

人钠/碘同向转运体基因转染胶质瘤细胞介导放射性碘治疗的研究

目的 在体外细胞实验中证明转染人钠/碘同向转运体(hNIS)基因介导放射性碘治疗胶质瘤是有效的.方法 以脂质体转染法、用重组质粒将hNIS基因转染至人胶质瘤细胞株U251中.经过G418硫酸盐筛选获得稳定表达hNIS的细胞株(hNIS-U251),然后进行体外摄125I实验、NaClO4抑制实验、体外125I外流和内流实验,并绘制时间-放射性曲线.对经3700 MBq/L 131I处理的hNIS-U251细胞进行四甲基偶氮唑蓝(MTY)分析和流式细胞仪测定分析.两组间比较采用独立样本t检验,多组间比较用单因素方差分析(LSD法).结果 hNIS-U251细胞株可以摄取碘,其摄碘能力较U251细胞提高117倍左右[2种细胞所摄取125I分别为(50 469.88±997.29)和(432.92±89.28)计数·min-1].经131I处理后,hNIS-U251细胞株的细胞增殖活性低于U251细胞株,两者S期细胞比率(SPF)差异有统计学意义(t=35.5,P＜0.001);增殖指数(PI)差异有统计学意义(t=6.33,P＜0.05).结论 131I可以被hNIS-U251细胞摄取,而且可以有效地杀伤胶质瘤细胞.     

亲和素促排减轻荷瘤裸鼠放免治疗毒副作用的实验研究

本研究将1 88Re标记生物素化单克隆抗体 (McAb Bt)和亲和素 (Av)用于荷人结肠癌裸鼠模型 ,评价其在肿瘤放免治疗 (RIT)中的价值 ,现报道如下。一、材料与方法1.抗癌胚抗原 (CEA)单抗McAb的生物素化及1 88Re标记参照文献 [1,2 ]。2 .荷瘤裸鼠RIT实验。建立荷人结肠癌裸鼠模型。将荷瘤裸鼠随机分为 3组 ,每组 5只。①Av促排组 :先尾静脉注射1 88Re McAb Bt11 1MBq (2 0 μg) ,2 4h后再注射Av 80 μg;②未实施Av促排组 :尾静脉注射1 88Re McAb Bt 11 1MBq (2 0μg) ;③对照组 :尾静脉注射生理盐水 10 0μl。肿瘤体积的检测采用双…     

术中125I粒子植入治疗复发性脑胶质瘤的临床研究

目的 探讨复发性脑胶质瘤术中125I粒子植入治疗的近期治疗效果及并发症。 方法 回顾性分析58例复发性脑胶质瘤患者资料, 其中, 23例患者行单纯手术, 另外35例利用计算机三维治疗计划系统于术前或术中制定治疗计划, 术中依据所制定的剂量, 在肿瘤切除后的瘤床上植入125I粒子, 处方剂量为140~188 Gy。术后每2个月复查CT或MRI进行验证和质量评估, 随访8~32个月, 比较分析两组患者的肿瘤复发率、生存期及放射性并发症。 结果 单纯手术组中有20例复发, 复发率为87. 0%;有3例死于术后并发症。术中125I粒子植入治疗组中有23例复发, 复发率为65. 7%;有5例死于术后并发症, 4例发生顽固性脑水肿, 3例发生放射性脑坏死。术中125I粒子植入治疗组肿瘤复发时间[(97. 5±15. 3)周]明显长于单纯手术组[(62. 5±13. 6)周](t= 9. 21, P < 0. 05), 生存期[(60. 3±7. 1)周]亦明显长于单纯手术组[(43. 1±5. 5)周](t=13. 03, P < 0. 05)。单因素变量分析结果显示, 世界卫生组织肿瘤病理分级与肿瘤切除程度是影响患者生存率的独立因素。 结论 术中125I粒子植入治疗可降低脑胶质瘤的复发率, 有效增加复发性脑胶质瘤患者的生存时间。     

125I粒子近距离照射在肿瘤治疗中的应用

125I的生物物理学特性适合近距离照射治疗,125I作为粒子源植入体内,目前在国外广泛用于各种恶性肿瘤的治疗,尤其是用于前列腺癌的治疗已相当成熟,取得了良好的疗效,但在治疗中还存在一定的问题.     

Radiation protection and dosimetry issues for patients with prostate cancer after I-125 low-dose-rate brachytherapy permanent implant

PurposeThe aim of this work was to analyze the exposure rates measured in the proximity of patients who underwent prostate low-dose-rate brachytherapy with I-125 implant. Effective doses to relatives and to population were computed to estimate the time to reach radioprotection dose constraints.Methods and MaterialsMeasurements were obtained from 180 patients, whereas the body mass index was calculated and reported for 77 patients. The day after the implant, $\dot{K}$ measurements were conducted at various skin distances and positions and converted to effective doses. A theoretical model was developed to estimate effective doses from total implanted activity. The latter was approximated with a 10-mL vial inside the patient.ResultsThe $\dot{K}$ measurements showed a low correlation with the total implanted activity, albeit an increasing trend of $\dot{K}$ was observed on increasing the activity. A stronger correlation was found between body mass index and $\dot{K}$ measurements.The effective dose to population is in general lower than dose constraints as well as the effective doses to relatives, with the exception of children and pregnant women, who command special precautions. We report differences between the experimental model– and theoretical model–based dose evaluation together with their comparison with previous studies found in literature.ConclusionsBased on the $\dot{K}$ measurements and the results of the present analysis, it is possible to provide the patient with radiation safety instructions specifically tailored to his relatives’ habits and working environment.     

放射性125I粒子离体照射模型的建立和测量

目的建立放射性^125I粒子离体照射模型,研究模型中离体细胞照射平面的剂量和剂量分布。方法应用14颗粒子环形排布的照射模型,用临床上常用的6711型^125I粒子。实验前随机抽取20%的粒子校正,应用TLD元件对模型进行测量。先用37MBq的^125I粒子照射6d,测量细胞平面受照剂量并计算初始剂量率;然后用同样活度的^125I粒子照射10d后测量,与用公式计算的照射剂量值进行比较。结果TLD标定：测量读数和照射剂量拟合为线性关系。单颗粒子活度测量值与出厂标定值相差〈±5%。照射6d测量细胞平面累积剂量为1.58Gy,计算初始剂量率为0.273Gy/d;照射10d的测量值和理论计算值分别为2.43和2.57Gy,两者相差5.76%。根据对模型的测量和计算,可推导出在不同的初始剂量率下受照剂量和照射时间的关系。结论建立的放射性125I粒子离体照射模型简便实用,可用于放射生物学实验研究。受照剂量与照射时间关系的建立,为今后开展放射性125I粒子相对生物效应的研究和对肿瘤细胞作用机制的研究奠定基础。     

Assessing protection against radiation exposure after prostate 125I brachytherapy

PurposeTo expand the radiation dose rate measurement data set by measuring radiation under various prostate ¹²⁵I brachytherapy situations.Methods and MaterialsMeasurements were obtained from 63 consecutive unselected patients at Tokyo Medical Center, Japan. Differences in factors during measurements, such as body postures, distances from the skin surface, and measurement directions were considered. Furthermore, shielding effects of lead-lined underwear, consisting mainly of 0.1-mm thickness of lead, were also assessed.ResultsRadiation exposure varies according to the patient's body posture, with results differing as much as approximately 40.0% in measured radiation dose rates at 30 cm from the anterior skin surface. Weight, body mass index, and tissue thickness showed good correlations with measured radiation dose rates. The magnitude of radiation exposure attenuation by shielding was approximately 95.8%, similar to the attenuation ratio based on tissue measurements made in the lateral direction. The respective mean times required to reach 1 mSv were 1.2, 7.6, and 65.4 days in the standing position and 0.6, 4.6, and 40.4 days in the supine position at the site of contact, and at 30 and 100 cm from the anterior skin surface.ConclusionsThis study obtained supplemental information pertaining to radiological protection and confirmed that shielding can be an effective tool for reducing exposures.     

Intraoperative I Vicryl mesh brachytherapy after sublobar resection for high-risk stage I nonsmall cell lung cancer

PURPOSE: To assess the feasibility and outcomes of (125)I Vicryl mesh brachytherapy after sublobar resection in stage I non small cell lung cancer (NSCLC) patients with poor pulmonary function. METHODS AND MATERIALS: Between January 1997 and July 2004, patients with poor cardiopulmonary reserve who had stage IA and IB (T1-2 N0 M0) NSCLC and a forced expiratory volume in 1s (FEV(1)) of > micro=0.6L were considered for limited surgical resection either by an open or video-assisted thoracoscopic procedure and for a subsequent (125)I Vicryl mesh brachytherapy implant. Mediastinal and hilar lymph node staging was performed routinely in all patients. After clear margins were obtained grossly and on frozen section, a single-plane (125)I implant was designed to encompass a plane consisting of the staple line and a 2-cm margin of surrounding visceral pleura. The implant was introduced through the surgical incision and sutured to the visceral pleura. A prescribed dose of 100-120 y was delivered to a volume within 0.5 cm rom the plane of the implant. Follow-up orthogonal films or CTs were obtained for dosimetric analysis. Kaplan-Meier analyses were used to estimate the local control, locoregional control, and overall survival rates. RESULTS: Of the 110 patients, 65 had stage IA and 45 had stage IB NSCLC. The mean preoperative FEV(1) was 47% of the predicted volume. With a median follow-up of 11 months (range 1-68 months), there were four recurrences within the radiation volume. The estimated 5-year local (in-field) control, locoregional control, and overall survival rates were 90%, 61%, and 18%, respectively. CONCLUSION: Vicryl mesh brachytherapy after sublobar resection for high-risk stage I NSCLC patients is a feasible procedure, which results in an excellent local (in-field) control rate.     

Enhanced efficiency and ergonomics of an intraoperative automated prostate brachytherapy delivery technique

INTRODUCTION: In 2003, the Tom Baker Cancer Centre started a prostate brachytherapy program using Iodine-125 seeds, intraoperative treatment planning, and an automated remote afterloader, the seedSelectron. Over a 3-month period in 2004-2005, technologic changes were implemented with the intent of reducing the time spent in the operating room and improving ergonomics for the radiation oncologist/surgeon. New commercial software including inverse planning was installed, concurrent needle insertion and seed train building was implemented, and additional hardware (a slave monitor) was connected to the system. PURPOSE: To demonstrate that, with these enhancements, dosimetry is not compromised, whereas efficiency is significantly improved. METHODS: Interactive inverse planning was used to create the treatment plans in the operating room. Seed-spacer trains were built concurrently with each needle's insertion guided by rotating the ultrasound probe to the correct sagittal plane using the Needle Navigator feature. Needles were built, inserted, and delivered one needle at a time. Needle coordinate and insert positions were verified on the live ultrasound image displayed on both the slave monitor positioned above the patient's pelvis and the operator console. Dosimetry parameters (D(90) and V(100)), numbers of seeds, and OR times were compared for 20 patients before and 11 patients after the implementation of the concurrent insertion and build protocol combined with inverse planning and the slave monitor. RESULTS: Operating room (OR) times (probe in to probe out) were reduced by 33 min and the number of seeds per unit volume by 3% on an average. The majority of the decrease in time is due to the concurrent building and insertion of needles. Before and after the new technique, average postplan D(90) and V(100) values at 4 weeks after the implant were the same to within 4 Gy and 0.1%, respectively. The range (max-min) of D(90) decreased by 20% of the mean dose and the V(100) range decreased by 6% with the new technique. Adding the slave monitor improved quality assurance of the delivery process and ergonomics for physicians. CONCLUSIONS: The concurrent insertion and build protocol, together with inverse planning and the slave monitor, have decreased OR times with greater consistency in the delivered dose distribution.     

Surgery combined with iodine-125 interstitial brachytherapy for treatment of parotid adenoid cystic carcinoma: A single-institution experience

PurposeThe purpose of this study was to analyze the effectiveness and safety of the combination of surgery plus postoperative iodine-125 interstitial brachytherapy for treatment of adenoid cystic carcinoma (ACC) of the parotid.Methods and MaterialsThis study included a retrospective analysis of the data of patients who underwent postoperative iodine-125 interstitial brachytherapy for histology-confirmed ACC of the parotid between January 2002 and November 2018 in Peking University Hospital of Stomatology. Acute and long-term radiation-related toxicities were assessed by the criteria of the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer. Multivariate analysis was used to identify the factors affecting overall survival, disease-free survival (DFS), and distant metastasis–free survival (DMFS).ResultsA total of 86 patients (53 women; median age 50 years, SD = 13.1) were included. Median followup was for 45.5 months. About half the patients (44/86, 51.3%) had clinical stage IV disease. Local recurrence occurred in 11 of 86 (12.8%) patients. No patient had nodal metastases in the followup period. The five- and 10-year DFS rates were 74.8% and 66.6%, respectively. The mean DMFS was 60.6 months. On multivariate analysis, preoperative facial palsy, type of surgery, perineural spread (PNS), and distant metastases were independent prognostic factors for DFS; preoperative facial palsy, nodal metastases, and PNS were independent prognostic factors for overall survival; and preoperative facial palsy, type of surgery, PNS, and pathological type were independent prognostic factor for DMFS.ConclusionsThe combination of surgery and iodine-125 interstitial brachytherapy appears to be an effective and safe treatment for primary ACC of the parotid.     

~(125)Ⅰ植入治疗源的剂量学参数的Monte Carlo模拟

放射性粒子源125I已被广泛用于前列腺和眼睛的植入治疗中。本文采用EGS5蒙特卡罗代码计算了美国医用物理学协会（AAPM）TG-43U1报告中推荐的型号为6711125I近距治疗源（活性区长取0.28cm）的剂量学参数,如剂量率常数、径向剂量函数和各向异性函数。剂量率常数为0.959cGy/h/U,与TG-43U1推荐值和Dolan等已发表的值相差在2.0%以内 径向剂量函数数值与二者均符合较好 随着角度和距离的增加,各向异性函数值数值与二者的复合程度趋佳。并给出了实用性较强的径向剂量函数的拟合公式。     

~(125)I粒子近距离放射治疗恶性梗阻性黄疸有效性及安全性的Meta分析

目的通过Meta分析评估~(125)I粒子近距离放射治疗恶性梗阻性黄疸的疗效及安全性。方法检索中国生物医学数据库(CBM)、万方数据库、中国学术期刊全文数据库(CNKI)、维普数据库(VIP)、Pubmed、Cochrane library、Embase、Ovid建库以来到2018年3月已公开发表的~(125)I粒子治疗恶性梗阻性黄疸的随机对照试验文献。由2名研究者独立筛选文献、评价文献质量、提取数据,通过Rev Man5.3软件进行Meta分析。结果符合纳入标准的文献共15篇,共1 015例病人。Meta分析结果显示,~(125)I放射组病人1年生存率高于对照组(RR=2.06,95%CI:1.62～2.62,P0.000 1),生存风险低于对照组(HR=0.38,95%CI:0.26～0.57,P0.000 1);~(125)I放射组术后1个月总胆红素低于对照组(WMD=-6.08,95%CI:-9.05～-3.10,P0.000 1),术后3个月总胆红素也低于对照组(WMD=-37.72,95%CI:-44.99～-30.45,P0.000 1);胆道通畅情况优于对照组;术后1个月~(125)I近距离放射组肿瘤缩小,而对照组肿瘤增大(SMD=-2.77,95%CI:-5.10～0.44,P=0.02);术后1个月2组谷丙转氨酶差异无统计学意义(WMD=-3.06,95%CI:-7.97～1.85,P=0.22);术后常见并发症发生率差异无统计学意义(RR=0.96,95%CI:0.68～1.35,P=0.80);~(125)I近距离放射组的病人疼痛缓解率明显优于对照组(RR=21.08,95%CI:4.43～100.16,P=0.000 1)。结论与单纯放置支架、胆道引流术相比,~(125)I近距离放射能有效地延长恶性梗阻性黄疸病人的生存时间和胆道通畅时间,并能抑制肿瘤生长和缓解疼痛等,同时并不增加肝功能损害和手术并发症。     

^125I粒子植入治疗荷人肝癌裸鼠移植瘤的实验研究

目的 探讨^125I粒子植入对荷人肝癌裸鼠移植瘤生长和细胞增殖及凋亡相关蛋白的影响。方法 建立12只荷人肝癌BEL-7402裸鼠模型，治疗组和对照组各6只。治疗组每只裸鼠移植瘤内植入1枚活度为33．3MBq的^125I粒子，对照组不进行干预。治疗后每3～4d测量1次肿瘤直径，并计算治疗组肿瘤的体积抑制率。21d后处死裸鼠，制作肿瘤组织标本，进行常规病理学检查和免疫组织化学检测增殖细胞核抗原（PCNA）、bcl-2和bax的表达。结果 ^125I粒子治疗组肿瘤体积最大抑制率为49．2％，病理检查显示近粒子处肿瘤细胞变性坏死，远离粒子处可见存活肿瘤细胞。免疫组织化学显示治疗组PCNA表达强度和bcl-2／bax比值均低于对照组。结论 ^125I粒子植入低剂量持续照射可直接杀死荷瘤鼠肝癌细胞或抑制肿瘤生长。