淋巴结阳性宫颈癌患者术后三维适形放疗的临床意义

[目的]探讨三维适形放射治疗技术减少宫颈癌根治术后放疗患者小肠、直肠、膀胱受照体积.[方法]应用三维适形放射治疗计划系统分析我院2004年2月～l2月住院60例宫颈癌根治术后需行放疗的宫颈癌患者,建立剂量体积直方图和计量参数,比较每一位患者前后对穿照射野的传统治疗计划和四野三维适形治疗计划.观察放疗并发症,比较两组术后放疗的效果.[结果]传统技术和适形技术的平均肿瘤控制概率分别63%和62%,接受≥95%处方剂量的小肠、直肠、膀胱体积在前后对穿照射野的传统治疗技术中为41%、98%、97%,在三维适形治疗技术中为21%、23%、61%(P＜0.01).适形技术中肾脏的受照量轻微升高,适形与传统计划相比直肠乙状结肠的平均最小剂量(D95)从48.29GY减少至4.51GY.在近期并发症中,适形技术组直肠反应发生率34.5%,传统技术组为62%,两组差异有统计学意义(P＜0.05),膀胱反应适形技术组为16%,传统技术组为39.7%,两组对比差异有统计学意义(P＜0.05).远期并发症有轻、中度放射性直肠炎,适形技术组14.3%,传统技术组35.7%,两组比较差异有统计学意义(P＜0.05),放射性膀胱炎适形技术组为11%,传统技术组为32%,两组比较差异有统计学意义(P＜0.05).[结论]三维适形治疗技术能显著减少小肠受照体积,对直肠膀胱受照量的降低亦具有优势,可提高肿瘤区域的剂量,从而提高肿瘤控制率而不会增加正常组织的毒性反应.     

三维适形放射治疗中晚期宫颈癌临床分析

目的 评价三维适形放疗在治疗中晚期宫颈癌中的临床疗效.方法 治疗组40例中晚期宫颈癌接受三维适形放疗,对照组40例接受腔内后装放射治疗.所有患者前5周均接受全盆腔外照射剂量5 000 cGy及同步化疗.结果 治疗组CR 77.5%,PR 10.0%,有效率87.5%;对照组CR 32.5%,PR 40.0%,有效率72.5%,治疗组明显高于对照组(P＜0.05).结论 全盆腔外照射后三维适形放疗,能提高中晚期宫颈癌的局部控制率,对直肠、膀胱受照量的降低也具有优势,可提高肿瘤区域的剂量,提高肿瘤控制率而不会增加正常组织的毒性反应.     

宫颈癌术后三维适形放疗与调强放疗疗效及毒副反应分析

目的比较宫颈癌术后有高危因素病人三维适形放疗与调强放疗的疗效及急性放疗反应。方法 99例宫颈癌术后放疗病人,其中调强放疗55例,三维适形放疗44例,比较两种治疗方法的疗效及急性放疗反应。结果调强与三维适形放疗比较小肠、直肠、膀胱的受照射剂量均明显减小,p均<0.05;调强与三维适形放疗比较,急慢性毒副反应明显降低;但1、2、3年存活率比较差异无统计学意义,p>0.05。结论调强放疗技术使宫颈癌术后病人的靶区获得理想的剂量分布,邻近危险器官得到很好的保护,毒副反应可以耐受,对生存率的提高有待于进一步研究。     

多叶光栅子宫内膜癌三维适形放疗与二维放疗计划的比较分析

目的:评估多叶光栅子宫内膜癌三维适形放疗计划的剂量分布特点。方法:对20例子宫内膜癌患者分别进行三维适形放疗和二维放疗计划设计,根据剂量、体积直方图等参数对两者剂量分布进行分析和评估。结果:与二维放疗相比,三维适形放疗的靶区剂量分布更均匀,直肠和膀胧的受照剂量及体积明显降低。结论:使用多叶光栅三维适形放疗可安全地增加子宫内膜癌的照射剂量,有助于提高子宫内膜癌局控率,同时又能更好地保护周围正常组织。     

宫颈癌术后调强放射治疗和三维适形放射治疗剂量对比

目的 研究宫颈癌术后调强放射治疗（IMRT）和三维适形放射治疗（3D-CRT）时靶区及其周围正常组织受照剂量的差异.方法 采用CMS公司的Xio 44放射治疗计划系统分别对12例宫颈癌术后患者进行3D-CRT和IMRT计划设计,95%PTV剂量50 Gy.利用剂量-体积直方图（DVH）计算靶区剂量适形指数（Cindex）和小肠、直肠、膀胱等正常器官受量以进行对比.计划执行采用Elekta公司的Precise电子直线加速器（6MV光子线）.结果 与3D-CRT相比,IMRT计划的直肠受到40 Gy、膀胱受到45 Gy、小肠受到50 Gy照射的体积所受剂量分别下降了375%、368%和91%,靶区的剂量适形指数提高了189%.同时,IMRT计划的直肠、膀胱平均剂量也显著低于3D-CRT计划.结论 宫颈癌术后IMRT剂量分布优于3D-CRT.     

胰腺癌三维立体定向适形放疗计划设计探讨

目的：探讨胰腺癌的三维适形放射治疗计划设计。方法：对36例原发患者，根据医师要求的PTV和周围正常敏感器官限制的受量设计三维适形放射治疗计划，结合剂量-体积直方图选择最佳方案。结果：以ICRU剂量参考点（靶中心点剂量）剂量归一，95％剂量线均能包绕95％以上的PTV。结论：在胰腺肿瘤的治疗计划设计时，对位于不同部位的病灶采用不同的设计；正常组织的受照体积的大小和受照剂量直接影响患者的放射治疗反应。     

宫颈癌多固定野三维适形放疗铅挡块与多叶准直器应用的比较

目的 介绍宫颈癌多固定野三维适形放疗铅挡块与多叶准直器的方法。方法 将宫颈癌多固定野三维适形放疗铅挡块与多叶准直器的应用进行比较。结果 宫颈癌多固定野三维适形放疗铅挡块与多叶准直器对肿瘤组织和危及器官的实际受照剂量的影响不同。结论 在多固定野三维适形放射治疗中,应根据肿瘤组织的放射致死剂量、危及器官的放射耐受剂量等科学、准确、有效地使用铅挡块和多叶准直器。     

宫颈癌三维适形放疗结合腔内后装放疗的疗效分析

目的 探讨三维适形放疗结合腔内后装放疗在宫颈癌治疗中的疗效。方法 将包头市某医院2004年5月至2006年5月对收治的82例Ⅱ期以上宫颈癌患者通过治疗方式不同分为两组,一组为三维适形放疗结合腔内后装放疗治疗组,病例数为43例,使90%等剂量曲线包绕靶区,肿瘤剂量45Gy,腔内照射5~6次,A点总剂量75~81Gy。另一组为单纯三维适形放疗治疗组,病例数为39例,肿瘤剂量55~60Gy。结果 三维适形放疗结合腔内后装放疗治疗组43例宫颈癌患者总有效率为97.7%。单纯三维适形放疗治疗组39例宫颈癌患者总有效率为84.6%。两组总有效率比较差异有统计学意义(P < 0.05);三维适形放疗结合腔内后装放疗治疗组3年以上生存率76.7%,1年以上生存率100%。单纯三维适形放疗治疗组3年以上生存率61.5%,1年以上生存率94.9%。两组1、3年生存率比较差异无统计学意义(P > 0.05)。结论 三维适形放疗结合腔内后装放疗治疗宫颈癌可提高靶区剂量,周围器官得到有效保护,放射反应小,治疗精度高,显著提高了肿瘤局部控制率和生存率,提高患者对放疗的耐受性。     

乳腺癌保乳术后调强放疗的剂量学优化分析

目的 比较乳腺癌保乳术后常规经典的切线野(2D)放疗、三维适形(3D-CRT)放疗、以及两适形野+两调强野的混合调强技术(3D_4F_H_IMRT)放疗三种方式,使靶区剂量分布更均匀以及对周围组织器官损伤减少差异。方法 我院2011.1~2011.3收治乳腺癌保乳术后患者15人,应用以上3种照射技术设计治疗方案。2Gy/25次总剂量50Gy。根据积分剂量体积直方图比较靶区剂量和正常组织器官受量。结果 常规经典的切线野(2D)、三维适形(3F-CRT)放疗剂量分布明显在靶区形成剂量热点。两适形野+两调强野的混合调强技术(3D_4F_H_IMRT),剂量分布更均匀,乳腺周围正常组织及患侧肺和心脏受照剂量更低,皮肤反应更轻。临床效果最佳。结论 两适形野+两调强野的混合调强技术(3D_4F_H_IMRT),在剂量分布上更有利于乳腺癌患者放射治疗。     

适形调强放疗应用中应注意的问题

适形调强放疗(IMRT)是近年来发展期起来的放射治疗技术,特点是靶区剂量准确、分布均匀、正常器官受照剂量小、保护重要器官,减少放射治疗的并发症和放疗后生存质量,显著提高肿瘤控制率及患者生存率。     

胰腺癌体部伽玛刀治疗的剂量学研究

目的：比较并分析OUR-QGD型体部伽玛刀（γ-SBRT）与三维适形放射治疗（3D-CRT）在胰腺癌治疗计划中剂量学数据,为胰腺癌放射治疗技术的选择提供依据。方法：分别对10例胰腺癌患者（胰头癌、胰体尾癌各5例）制定体部伽玛刀及三维适形放射治疗计划,处方剂量均要求50 Gy剂量曲线包绕肿瘤计划靶体积（PTV）。比较两种PTV的适形指数和均匀指数,根据剂量体积直方图（DVH）显示的结果计算靶区剂量和危险器官（OARs）照射剂量。结果：3D-CRT计划的均匀指数好于γ-SBRT,两者适形度近似。γ-SBRT计划中靶区剂量明显高于3D-CRT,且OARs受照射剂量较低。结论：γ-SBRT治疗胰腺癌明显提高靶区照射剂量,更好的保护靶区周边正常组织,可以作为治疗胰腺癌安全有效的放射治疗技术。     

适形结合体部γ刀照射在宫颈癌放疗中的应用与研究

目的：探索适形结合体部γ刀照射在宫颈癌放射治疗中的应用。方法：将60例患者随机分成2组,对第1组进行宫颈癌调强适形放射治疗计划设计,第2组进行适形结合体部γ刀照射,分别设计适形和体部γ刀放疗计划,比对放疗计划的优劣性。结果：适形结合体部γ刀照射使直肠受量较小,对放射性直肠损伤小。结论：适形结合体部γ刀照射治疗宫颈癌使周围正常组织接受照射的体积小、副反应小,是一种有效的治疗方法。     

Preliminary results of conformal computed tomography (CT)-based intracavitary brachytherapy (ICBT) for locally advanced cervical cancer: a single institution's experience

Intracavitary brachytherapy using tandem and ovoids is an important component of definitive treatment for cervical cancer. In the present study, we analyzed the dose-volume histograms (DVHs) of the tumor volume and organs at risk including the sigmoid colon by CT-based treatment planning for high dose rate (HDR) intracavitary brachytherapy (ICBT) in cervical cancer. Seventeen patients with carcinoma of the cervix uteri were treated with external beam radiotherapy plus concurrent chemotherapy. For brachytherapy, the planning procedure started by performing a conventional plan which prescribed a dose of 6.5-7 Gy per fraction to point A, then optimized the dose based on CT imaging. Volumes and DVHs were calculated for the HR-CTV, bladder, rectum and sigmoid colon. The mean BED(2Gy) total doses of post-optimized plans of HR-CTV, bladder, rectum and sigmoid colon were: 89.6, 94.1, 74.0 and 69.8 Gy, respectively. For conventional plans, the calculated mean BED(2Gy) total doses of HR-CTV, bladder, rectum and sigmoid colon were 92.2, 120.1, 75.7 and 78.3 Gy, respectively. This study showed statistical significant higher BED(2Gy) total doses for bladder and sigmoid colon (p < 0.001) using conventional plans versus post-optimized, CT-based plans, while no difference between HR-CTV and rectum BED(2Gy) total doses could be detected. After a median follow-up of nineteen months, all seventeen patients had a clinical complete response. Two patients developed distant metastasis. Compared with conventional treatment, CT based brachytherapy planning was very effective in reducing doses to OARs, especially bladder and sigmoid colon whilst maintaining a high therapeutic dose for tumor target volumes in the treatment of cervical carcinoma.     

Dosimetric comparison of three-dimensional conformal radiotherapy in salvage radiotherapy for PSA relapse after radical prostatectomy

The purpose of this study is to compare three-dimensional conformal radiotherapy (3D-CRT) plans in a setting of salvage radiotherapy after radical prostatectomy (RP) and to simulate whether dose escalation is possible with the most adequate 3D-CRT technique. This study included consecutive 10 patients underwent salvage radiotherapy (RT) for biochemical relapse of prostate cancer after RP. Normal structures included the rectum, bladder, and femoral head. For each patient, four different treatment plans including four fields RT (4F-RT), dynamic conformal arc radiotherapy (DCAT), six fields RT (6F-RT), and DCAT with rectum hollow-out technique (DCAT-HO), were created to entire the prostate bed. The parameters of the maximum and mean doses received by organs at risk (OAR), target coverage, dose homogeneity for the planning target volume (PTV) were compared. All plans were considered to be clinically tolerable for PTV coverage and dose homogeneity. The rectum sparing at the high dose area for DCAT-HO was considered to be the most superior to those for other three techniques by comparison of the dose delivered to a 1%, 5%, and 10% volume of the rectum. In the simulation of dose escalation to 70 Gy with DCAT-HO, OAR met a requirement of the dose-volume constraints. However, in the simulation of dose escalation to 72 Gy, the rectum that receives 60 to 65 Gy and bladder that receives 65 Gy exceeded the optimal dose-volume constraints. DCAT-HO was considered to be one of the most appropriate techniques in 3D-CRT if dose escalation to 70 Gy might be needed in a setting of salvage RT after RP in the future.     

CT/MRI诊断影像融合对非小细胞肺癌脑转移瘤靶区及三维适形治疗影响

目的：比较CT图像和CT/MRI融合图像来源的肺癌脑转移肿瘤靶区,评价CT/MRI融合靶区容积应用于三维适形放射治疗时,对治疗剂量的影响。方法：将20例非小细胞肺癌脑转移患者的增强CT和MRI扫描的图像传送至图像处理工作站,在CT和CT/MRI融合图像上分别勾画GTV和周围重要的器官。每个病例分别在CT图像和CT/MRI融合图像都做1个三维适形放射治疗计划。肿瘤的处方剂量为60 Gy,比较2个治疗计划中肿瘤靶区的95%容积（D95）受照平均剂量、周围正常组织的5%容积（D5）受照平均剂量。结果：CT/MRI融合图像上的肿瘤靶区平均比CT上的肿瘤靶区大21.32％。用CT上勾画的靶区有一部分肿瘤处于低剂量区,CT/MRI融合图像上的靶区D95剂量分布较好,但在周围重要器官的剂量分布较高。结论：CT/MRI融合图像有助于靶区的确定,在三维适形放射治疗计划上的肿瘤靶区剂量分布足够,能提高靶区勾画的准确性,更利于精确放疗的实施。     

Approaches to individual radiotherapy in breast cancer: individual risk estimation and individualized techniques

INTRODUCTION: Radiotherapy comprises an integral part of the curative therapy of breast cancer by improving the locoregional control and survival when given on an individualized basis. Conformal radiotherapy and three-dimensional radiation treatment planning enhance the safety of radiotherapy by adjusting the irradiated volume to the shape of the target volume, and providing control of the radiation dose to the organs at risk (OARs). PATIENTS AND METHODS: The methods introduced at the authors' institute in 2002 are demonstrated. The breast/chest wall and lymph node areas were irradiated provided that there was a minimum risk of local or locoregional relapse of 10%. CT-based 3D radiotherapy treatment planning and individual patient-positioning were applied, with thermoplastic mask-fixation in the second part of the study. The dose constraints of the OARs were given in accordance with the literature recommendations. In the first group of patients, individually shaped blocks, in the second group, multileaf collimator, and in the third group, with the aim of a more homogenous dose-distribution in the target volume, intensity-modulated beams were applied. RESULTS: During the study, 737 breast cancer patients received conformal radiotherapy based on individual risk estimation. In 372 cases only local, while in 365 cases locoregional radiotherapy was delivered. The dose-homogeneity in the target volume was significantly improved in the second period of the study, when segments were superposed on the radiotherapy fields. The proportions of the target volumes irradiated with +/-10% of the planned dose in the breast/chest wall, axillary and supraclavicular lymph nodes and internal mammary lymph nodes varied between 90.5-94.2%, 84.1-93.8% and 86.7-91.6%, respectively, depending on the radiation technique used. The parameters indicating the dose to the ipsilateral lung or to the heart were significantly higher when locoregional radiotherapy was applied compared to that in case of local radiotherapy. Radiation dose to the ipsilateral lung and the heart was significantly reduced in the second part of the study when locoregional, but not when local radiotherapy was delivered. The introduction of individual immobilization by means of thermoplastic mask-fixation resulted in a relevant decrease in the uncertainty due to breathing motion and daily positioning errors, and also in a significant reduction of the dose to the contralateral breast. CONCLUSIONS: Adjuvant radiotherapy should be based on individual risk-benefit features. The need of the introduction of special techniques may be decided after the dose-volume analysis of the conformal radiotherapy plan based on 3D radiation treatment planning.     

Dosimetry analyses comparing high-dose-rate brachytherapy,administered as monotherapy for localized prostate cancer,with stereotactic body radiation therapy simulated using CyberKnife

The purpose of this study was to perform dosimetry analyses comparing high-dose-rate brachytherapy (HDR-BT) with simulated stereotactic body radiotherapy (SBRT). We selected six consecutive patients treated with HDR-BT monotherapy in 2010, and a CyberKnife SBRT plan was simulated for each patient using computed tomography images and the contouring set used in the HDR-BT plan for the actual treatment, but adding appropriate planning target volume (PTV) margins for SBRT. Then, dosimetric profiles for PTVs of the rectum, bladder and urethra were compared between the two modalities. The SBRT plan was more homogenous and provided lower dose concentration but better coverage for the PTV. The maximum doses in the rectum were higher in the HDR-BT plans. However, the HDR-BT plan provided a sharper dose fall-off around the PTV, resulting in a significant and considerable difference in volume sparing of the rectum with the appropriate PTV margins added for SBRT. While the rectum D5cm³ for HDR-BT and SBRT was 30.7 and 38.3 Gy (P < 0.01) and V40 was 16.3 and 20.8 cm³ (P < 0.01), respectively, SBRT was significantly superior in almost all dosimetric profiles for the bladder and urethra. These results suggest that SBRT as an alternative to HDR-BT in hypofractionated radiotherapy for prostate cancer might have an advantage for bladder and urethra dose sparing, but for the rectum only when proper PTV margins for SBRT are adopted.     

宫颈癌调强适形放射治疗的疗效分析

目的：分析调强适形放射治疗宫颈癌的临床疗效。方法：将42例宫颈癌患者,随机分为治疗组和对照组,治疗组21例为调强适形放射治疗,对照组患者21例为192Ir高剂量率腔内加体外放射治疗。结果：治疗组近期总有效率100%,对照组90.5%,两组比较差异无统计学意义（P〉0.05）。直肠放射性早期反应发生率治疗组为23.8%,对照组为76.2%;远期并发症发生率治疗组为9.5%,对照组为52.3%。膀胱放射性早期反应发生率治疗组为19.1%,对照组为61.9%,远期并发症发生率治疗组为4.7%,对照组为36.4%;治疗组和对照组比较差异有统计学意义（P〈0.05）。结论：调强适形放射治疗宫颈癌可以取得与常规治疗相似的局控率,但能明显降低放射反应,避免了繁杂的腔内治疗操作,提高了患者的生存质量,具有明显优势。     

不同能量X线在中段食管癌三维适形放疗中的比较

目的：探讨中段食管癌三维适形放疗（3DCRT）X线能量的选择.方法：选择21例中段食管癌患者,对每例患者分别采用6 MV和15 MV X线进行3DCRT治疗计划设计,同一患者的2个计划均使用相同的布野方案和剂量体积约束.比较2组治疗计划的计划靶区、危及器官及正常组织的剂量分布.结果：能量6MVX线治疗计划计划靶区的剂量分布、均匀性、适形度与15 MV的结果近似相同,均数差异无统计学意义（P＞0.05）;能量6 MV治疗计划危及器官脊髓、心脏,正常组织肺的受照剂量与15 MV的结果一致,均数差异无统计学意义（P＞0.05）.结论：在中段食管癌3DCRT中,不同能量X线照射后,肿瘤组织、危及器官和正常组织剂量分布无明显差异,但高能X线使患者受到更多的低剂量照射.因此,中段食管癌3DCRT时X线能量一般选用6 MV.     

Different effects of bladder distention on point A-based and 3D-conformal intracavitary brachytherapy planning for cervical cancer

This study sought to evaluate the differential effects of bladder distention on point A-based (AICBT) and three-dimensional conformal intracavitary brachytherapy (3D-ICBT) planning for cervical cancer. Two sets of CT scans were obtained for ten patients to evaluate the effect of bladder distention. After the first CT scan, with an empty bladder, a second set of CT scans was obtained with the bladder filled. The clinical target volume (CTV), bladder, rectum, and small bowel were delineated on each image set. The AICBT and 3D-ICBT plans were generated, and we compared the different planning techniques with respect to the dose characteristics of CTV and organs at risk. As a result of bladder distention, the mean dose (D₅₀) was decreased significantly and geometrical variations were observed in the bladder and small bowel, with acceptable minor changes in the CTV and rectum. The average D_{2 cm³}and D_{1 cm³}showed a significant change in the bladder and small bowel with AICBT; however, no change was detected with the 3D-ICBT planning. No significant dose change in the CTV or rectum was observed with either the AICBT or the 3D-ICBT plan. The effect of bladder distention on dosimetrical change in 3D-ICBT planning appears to be minimal, in comparison with AICBT planning.