食管癌等中心定位时斜野深度的误差分析

目的:分析食管癌等中心定位时两后斜野的深度误差及其对肿瘤剂量的影响。方法:收集2007年7月-12月进行放射治疗的68例食管癌病例,其中上段19例,中下段49例。利用荷兰核通Simulix-HQ模拟定位机,取仰卧治疗体位,等中心定位,读出射野深度。定位毕后使患者俯卧于定位床,找到等中心点,读出射野深度。结果:胸上段和中下段两后斜野在仰卧位和俯卧位时的深度上存在误差。颈段和胸上段的深度误差尤为显著。结论:颈段和胸上段食管癌等中心治疗时,仰卧位测得的两后斜野的肿瘤深度明显大于俯卧位。若以仰卧位定位时测得的肿瘤深度所给予的处方剂量,按俯卧位实测深度重新计算靶区吸收剂量,则胸上段食管肿瘤的总剂量将明显高于计划剂量。胸中下段的剂量变化不大。建议食管颈段和胸上段癌在仰卧位等中心治疗时,后斜野的深度应在俯卧位重新测量,以免过量照射造成不必要的放射损伤。     

颈段肿瘤放射治疗的改建定位法

模拟定位在肿瘤的放射治疗中具有重要的地位。正确的定位方法既能使肿瘤组织得到最大的放射治疗剂量,而且又能最大限度地保护正常组织。颈段肿瘤由于位于特殊部位,周围又有重要器官如脊髓,故其正确的定位更显重要。颈段肿瘤在放射治疗中的常见病如:颈段食管癌、喉癌、颈椎转移性肿瘤等。由于部分脊髓耐受放射线的最大允许剂量为40Ｇｙ,单纯使用垂直照射,对正常组织损伤较大,病灶部位往往达不到根治剂量。小于90°和大于270°的成角照射又不能很好地避开脊髓。最佳治疗方法是病人取仰卧位,机架旋转90°和270°的对野水平照射治疗。而此时最大…     

面颈联合野等中心治疗技术

面颈联合野等中心治疗技术黄继列萧达宜卢杰本文作者以鼻咽癌为例，介绍面颈联合野等中心照射技术的定位及治疗摆位的步骤。１模拟定位定位前，应检查模拟定位机的各项参数：即机架角、准直器角、治疗床旋转轴、床等中心轴均为初始位。检查模拟定位机的等中心与三维激光束...     

颈、胸上段食管癌MLC照射野的剂量学研究

目的 研究颈、胸上段食管癌使用MLC技术照射的剂量学特点。方法 14例经病理证实的颈、胸上段食管癌患者，行常规模拟定位制定常规治疗计划，并以此计划的照野中心为中心行CT扫描，用MLC技术设计第2种方案，同时将资料传入ADAC计划系统设计三维适形方案。将此3种方案的有关参数进行比较。结果 肿瘤长度的检查结果：钡透和内镜结果相近（P=0．108）、与CT比较有差异。常规模拟定位的中心与肿瘤的GTV中心在X、Y、Z轴上相差3．4、8．1、5．9him。以等中心点归一，给与处方剂量60Gy／30F，3种照野所覆盖的肿瘤体积占GTV的36％、94％、100％，占CTV23％、85％、92％。3种照野的100％GTV体积剂量分别为45、58、62Gy。V20分另Ⅱ为13．6％、13．5％、12，7％。结论 常规模拟定位难以满足颈、胸上段食管癌放疗的剂量要求。使用MLC技术的照野可以达到和适形照野相同的靶区剂量分布，建议使用但应注意脊髓的剂量。     

利用三角函数定位法测定乳腺癌放疗的有效治疗深度

目的:探讨乳腺癌放疗胸壁切线野等中心照射,确定等中心的定位方法.方法: 利用三角函数定位法,在模拟定位机下确定等中心照射的中心点.结果: 可以等中心定位,原点位于射野中心轴线的中点.结论:利用三角函数定位法行乳腺癌胸壁切线野放疗定位,可以快捷、准确地将射野参考点(即机器)等中心置于照射野中心轴线的中点,保证治疗的有效深度.     

鼻咽癌放射治疗射野衔接设计的探讨

背景与目的:放射治疗鼻咽癌,面颈联合野已作为标准的射野设计,用一个颈部等中心半束照接野解决了面颈联合野与颈部切线野的衔接问题,但面颈联合野内存在剂量冷点与热点,剂量均匀性差。因此,本研究试图就鼻咽癌放射治疗中面颈联合野与颈部切线野最合适的射野衔接设计作一些探讨。方法:分别用两种方法设野,一种方法用一个等中心,半束照射面颈联合野与颈部切线照射,另一种用两个等中心,面颈联合野用鼻咽等中心照射,选用适当的楔形角,床转一定的角度,下颈切线照射再用颈部等中心半束照。比较两种设野衔接的区别。结果:根据治疗计划系统(treatmentplanningsystem,TPS)计算,两种设计的面颈联合野与颈部切线野之间的剂量衔接处都无冷点热点。用两个等中心设计的面颈联合野与颈部切线野,面颈联合野加角头足方向楔形板和床转一定的角度,其剂量分布比单一中心设野更均匀,更合理。99%的等剂量线包容颅底及鼻咽处大体肿瘤体积(grosstumorvolume,GTV)时,下颈及口咽部最高点剂量为103%,而且高剂量区容积也小,而用单一等中心设野时,如果要使95%的等剂量线包含颅底及鼻咽处GTV时,最高点处剂量达120%以上。结论:用两个等中心设计面颈联合野和颈部切线照,比单一颈部等中心设野时,接野处可以达到与单一等中心相同的结果,即不产生冷点及热点,而且三维TPS显示比单一等中心更合理、更均匀。     

鼻咽癌放疗单中心上下半野照射模拟定位方法

在鼻咽癌的放疗中，单中心上下半野照射技术有效地解决了以往面颈联合野(面颈野) 双侧中下颈锁骨上下切线野(颈锁野)照射时两野间的衔接问题。一些学者已验证了采用该照射技术两野间的剂量分布比较合理，并提出规范准确的定位摆位方法，是保证该照射技术精确实施的重要前提。为此我们根据在定位工作中的实践经验，对该照射技术的定位方法进行归纳总结，现报告如下。     

食管癌放射治疗照射野大小的预测

对比分析61例食管癌X片和CT图,研究其外侵范围和规律,并对不同照射方法作了等剂量图,探讨以X片预测照射野大小。结果显示以食管为中心定位,前野宽6cm,二后斜野宽5cm,长15cm的照射野,90％等剂量区狭小,近50％患者的肿瘤可因外侵而未完全包括在90％等剂量区。对上,中胸段食管癌,长度<5cm而无外侵时,同中心照射,前野8cm,二后斜野6cm,50°,或前野7cm,二后斜野6cm,非同中心照射,可使100％患者原发灶在90％等剂量区内。长度>5cm或有外侵时,同中心照射前野8cm,二后斜野7cm,或非同中心照射,前野8cm,二后斜野6cm,可使90％患者的原发灶在90％等剂量区内。     

头颈部肿瘤放射治疗时体位误差的分析

为研究头颈部肿瘤放射治疗时体位误差 ,笔者回顾性分析了 1999年 11月至 2 0 0 0年 11月拍摄的 15例患者的模拟定位片和放射治疗体位证实片 ,现将结果报道如下。一、材料和方法1.一般资料 :15例经病理证实的头颈部肿瘤患者中鼻咽癌 10例 ,垂体瘤 3例 ,颅内肿瘤 2例。均用面罩固定和等中心技术照射。2 .摆位方法 :模拟定位时患者仰卧于模拟定位机床上(Ｎｕｃｌｅｔｒｏｎ ,ＳｉｍｕｌｉｘＭＣＲ96 48) ,面罩固定 ,透视下定好照射野后 ,将中间激光线、两侧水平激光线、照射野中心及照射野边界标记于面罩上 ,前后野和 (或 )侧野拍摄模拟定位片…     

鼻咽癌常规外照射放疗不同设野茎突后区剂量分析

  目的 探讨鼻咽癌(NPC)常规外照射不同设野时茎突后区的剂量学特点。方法 在1例NPC增强CT-SIM扫描后数字重建矢状位图像上，按目前常用的几种照射方法设野，I段采用面颈联合野，剂量．36Gy；Ⅱ段剂量34Gy，方法A、B、C均采用面颈分野，耳前野后缘分别位于外耳道后缘后0．5cm、1．0cm和1．5cm，方法D采用面颈联合缩野(后界避开脊髓)+颈后12MeV电子线野，方法E在方法A完成Ⅰ、Ⅱ段放疗后补充咽旁野16Gy。通过积分剂量体积直方图(DVH)及截面剂量分布图比较不同设野对茎突后区剂量的影响。结果 方法A、B部分茎突后区在Ⅱ段治疗中漏出照射野外，方法C有较多脊髓超过耐受量照射，方法D可满足临床剂量要求，方法E则靶区存在剂量热点。结论 NPC茎突后间隙肿瘤侵犯时应提倡使用方法D照射技术。     

An overview on applications of optical spectroscopy in cervical cancers

Despite advances in the treatment modalities, cervical cancers are one of the leading causes of cancer death among women. Pap smear and colposcopy are the existing screening methods and histopathology is the gold standard for diagnosis. However, these methods have been shown to be prone to reporting errors, which could be due to their subjective interpretation. Radiotherapy is the mainstay of treatment for the locally advanced stages of cervical cancers. The typical treatment regimen spans over 4 months, from the first fraction of radiation to clinical assessment of tumor response to radiotherapy. It is often noticed that due to intrinsic properties of tumors, patients with the same clinical stage and histological type respond differently to radiotherapy. Hence, there exists a need for the development of new methods for early diagnosis as well as for early prediction of tumor radioresponse. Optical spectroscopic methods have been shown to be potential alternatives for use in cancer diagnosis. In this review, we provide a brief background on the anatomy and histology of the uterine cervix and the etiology of cervical cancers; we briefly discuss the optical spectroscopic approach to cervical cancer diagnosis. A very brief discussion on radiation therapy and radiation resistance is also provided. We also share our experiences with the Raman spectroscopic methodologies in cervical cancer diagnosis as well as in the prediction of tumor radioresponse.     

Advanced imaging applications for locally advanced cervical cancer

Advanced imaging approaches (computed tomography, CT; magnetic resonance imaging, MRI; 18F-fluorodeoxyglucose positron emission tomography, FDG PET) have increased roles in cervical cancer staging and management. The recent FIGO (International Federation of Gynecology and Obstetrics) recommendations encouraged applications to assess the clinical extension of tumors rather than relying on clinical examinations and traditional non-cross sectional investigations. MRI appears to be better than CT for primary tumors and adjacent soft tissue involvement in the pelvis. FDG-PET/CT has increased in usage with a particular benefit for whole body evaluation of tumor metabolic activity. The potential benefits of advanced imaging are assisting selection of treatment based upon actual disease extent, to adequately treat a tumor with minimal normal tissue complications, and to predict the treatment outcomes. Furthermore, sophisticated external radiation treatment and brachytherapy absolutely require advanced imaging for target localization and radiation dose calculation.     

Correlation of tumor growth index with early treatment response in cervical carcinoma

Despite the recent progress in the management of cervical carcinoma, treatment failure is quite common and therefore it is necessary to identify predicting factors for tumor response. It is known that both cell proliferation and apoptosis determine the tumor growth index (TGI) which reflects the overall contribution of gene defects. Here we explored whether the TGI index could be a better predictor of response in comparison to cell proliferation or apoptosis as separate phenomena. Twenty-five patients with cervical carcinoma treated with radiation alone or neoadjuvant chemotherapy plus surgery were analyzed. Cell proliferation and apoptosis determined by PCNA immunohistochemical expression and tumor nucleosomes by ELISA, respectively, were used to calculate the TGI, which was analyzed with regard to early tumor response. Our results show that most patients with a negative TGI had early response suggesting increased tumor sensitivity(p = 0.0186). On the other hand, patients with a positive TGI were more resistant to treatment. TGI was not related to age, clinical stage or tumor size. In conclusion, the results of this study show that the determination of the TGI, but no cell proliferation or apoptosis, as separate events, is able to predict an early treatment response to either radiation or chemotherapy in cervical carcinoma.     

宫颈癌放化疗联合热疗的疗效及MRI对其评价的临床价值

目的 探讨MRI影像学方法对放化疗联合热疗治疗宫颈癌的临床疗效的评价价值.方法 选取58例宫颈癌患者,随机分为联合组(29例)和对照组(29例).联合组采用放化疗联合热疗治疗,对照组采用单纯的放化疗治疗,2组疗程均为5～6周.评价2组治疗前后MRI成像及ADC值在宫颈癌放化疗联合热疗治疗后监测肿瘤变化的价值.结果 联合组和对照组的肿瘤缓解率分别为72.41％和61.72％;联合组、对照组患者治疗后ADC均值较之前均有所升高,且联合组ADC均值(1.99±0.28)高于对照组(1.54±0.25);P均＜0.05,数据具有统计学意义.结论 联合组治疗宫颈癌疗效优于对照组,MRI具有无辐射、无创伤等优点,能通过影像及ADC值检测肿瘤的生长及变化,在宫颈癌治疗的疗效评价中起着重要作用.     

Carcinoma of the nasopharynx an optimization of radiotherapeutic management for tumor control and spinal cord injury

A series of 131 patients with carcinoma of the nasopharynx were seen at the University of Chicago between 1949 and 1977. Within this series a subset of 96 patients received initial radiation treatment with curative intent at our institution, and comprises the basis of this report. Treatment doses to both the primary tumor site and the cervical spinal cord were converted to nominal standard doses (NSD). The patients were categorized into NSD intervals from 1200 to greater than 2 100 ret with corresponding incidence of complication: radiation induced cervical cord myelitis and recurrence at the primary site. Paired dose-response curves are presented that show tumor ablation and cervical myelitis as a complication of treatment versus NSD. The 5 % and 10 % incidence levels of radiation induced cervical myelitis are 1450 and 1750 ret, respectively. The therapeutic operating characteristic (TOC) curve of probability of tumor ablation versus the probability of cervical myelitis is developed and shown. A 10 % complication rate resulted from tumor control rates of 53% and 33% for T1, T2 and T3, T4 primary lesions, respectively. An additional 5% increase in cervical myelitis resulted from a 15 % gain in tumor ablation within all levels of primary tumor extension. Because of the higher tolerance of the cervical spinal cord and the poor prognosis for those patients who developed a recurrence at the primary site, the more aggressive treatment approach to all stages of nasopharyngeal carcinoma is proposed.     

Raising hemoglobin: an opportunity for increasing survival?

Although the association between low hemoglobin levels and poorer outcomes in radiation oncology has long been recognized, anemia is often overlooked and untreated. However, a growing body of clinical evidence now indicates that low hemoglobin levels during radiation treatment are associated with decreased response and survival following radiotherapy. For example, a large Canadian retrospective study in patients receiving radical radiotherapy for cervical cancer showed that the 5-year survival rate was 19% higher in those whose hemoglobin during radiation treatment was =12 g/dl compared to those with levels <12 g/dl. The data suggest that clinical trials need to be performed to determine whether increasing hemoglobin levels leads to improved local control and survival. The mechanism by which low hemoglobin levels could cause poorer outcomes is not well understood and needs further elucidation. It is postulated that lower hemoglobin levels resulting in decreased oxygen carrying capacity may lead to increased tumor hypoxia, radiation resistance and increased tumor angiogenesis. The interrelationship of low hemoglobin levels, hypoxia, tumor angiogenesis and survival is explored in this article.     

宫颈癌放射治疗疗效的MRI评价

目的分析宫颈癌放射治疗中与后MRI表现,探讨MRI成像对宫颈癌放射治疗疗效评估的价值。方法23例经病理证实的宫颈癌患者在放射治疗前、中及后不同时间段行盆腔的轴位T1WI,轴位及矢状位T2WI,冠状位SPIR,以及GDDTPA增强后T1WI的轴位、冠状位、矢状位扫描。在MRI图像上观察肿瘤在放射治疗前、后的大小及信号改变。结果外照射结束时,9例肿瘤缩小率在85%以下,14例>85%。T1WI增强扫描7例见肿瘤内出现“无强化区”,其中6例放射治疗结束后有肿瘤残留;16例肿瘤未见“无强化区”,其中13例肿瘤缩小率>85%,仅2例放射治疗后有肿瘤残留。MRI图像上,肿瘤痊愈表现为T2WI、SPIR序列呈低信号,T1WI增强扫描轻微强化或无强化。结论MRI成像可反应肿瘤对射线的疗效。外照射结束时肿瘤容积缩小程度与T1WI增强肿瘤内有无“无强化区”是预测放射治疗效果的重要观测指标。     

A case of multiple bone metastases from gastric cancer successfully treated with chemo-radiotherapy

A 75-year-old man underwent distal gastrectomy for gastric cancer (CY+, Stage IV) in June 2009. About 4 months after surgery, he had a strong pain in a right shoulder, and became writing difficulty. Some imaging examinations revealed multiple bone metastases, and it was diagnosed that the pain was caused by the tumor of cervical spine. Systemic chemotherapy was started using a regimen of S-1/CDDP, and radiotherapy (30 Gy) was performed for the cervical tumor at the same time. After two-course of the chemotherapy, the shoulder pain disappeared. About 12 months after surgery, he had a strong pain in a left leg, and became walking difficulty. Some imaging examinations revealed a progression of the tumor of lumbar spine. Radiotherapy (30 Gy) was demonstrated for the tumor. After the treatment, the leg pain disappeared. We experienced a case of multiple bone metastases successfully treated with chemo-radiotherapy.     

Nasopharyngeal carcinomas: analysis of patient, tumor and treatment characteristics determining outcome.

PURPOSE: The present study reviews the experience in treatment of 447 patients with nasopharyngeal carcinomas, analyzing patient, tumor and treatment characteristics determining outcome. MATERIALS AND METHODS: There were 322 males and 125 females, their ages ranging from 7 to 85 years (median, 45 years). Two-hundred and seventy-two patients had World Health Organization (WHO) type 3 carcinomas, 123 patients had T4 tumors and 320 patients had metastatic cervical lymph nodes. Three-hundred and eight patients were treated with radiation therapy alone and 139 patients with chemotherapy in combination with radiation therapy. Cumulative radiation dose to primary tumor ranged from 50 to 76Gy (median, 70Gy) and radiation dose to metastatic cervical lymph nodes ranged from 46 to 74Gy (median, 66Gy). RESULTS: Follow-up ranged from 0.1 to 19.5 years (mean, 7.6 years). Local complete response was achieved in 357 patients. In multivariate analysis, T-classification, cumulative radiation dose to primary tumor and treatment with chemotherapy in combination with radiation therapy predicted local response. Nodal complete response was achieved in 272 patients. In multivariate analysis, N-classification and radiation dose to metastatic cervical lymph nodes predicted nodal response. Local failure was observed in 70 patients, nodal failure in 35 patients and systemic failure in 114 patients. Overall survival, disease-free survival and disease-specific survival were 33, 32 and 37%, respectively, at 10 years. In multivariate analysis, age, T-classification, N-classification, radiation dose and treatment with chemotherapy in combination with radiation therapy predicted overall survival whereas T-classification, N-classification, radiation dose and treatment with chemotherapy in combination with radiation therapy predicted both disease-free survival and disease-specific survival. CONCLUSIONS: Radiation therapy alone appears to be an adequate and viable treatment for patients with early-stage nasopharyngeal carcinomas, whereas treatment with chemotherapy in combination with radiation therapy appears to improve outcome for patients with advanced-stage nasopharyngeal carcinomas.     

Improving the consistency in cervical esophageal target volume definition by special training

PURPOSE: Three-dimensional conformal radiation therapy requires the precise definition of the target volume. Its potential benefits could be offset by the inconsistency in target definition by radiation oncologists. In a previous survey of radiation oncologists, a large degree of variation in target volume definition of cervical esophageal cancer was noted for the boost phase of radiotherapy. The present study evaluated whether special training could improve the consistency in target volume definitions. METHODS AND MATERIALS: A pre-training survey was performed to establish baseline values. This was followed by a special one-on-one training session on treatment planning based on the RTOG 94-05 protocol to 12 radiation oncologists. Target volumes were redrawn immediately and at 1-2 months later. Post-training vs. pre-training target volumes were compared. RESULTS: There was less variability in the longitudinal positions of the target volumes post-training compared to pre-training (p < 0.05 in 5 of 6 comparisons). One case had more variability due to the lack of a visible gross tumor on CT scans. Transverse contours of target volumes did not show any significant difference pre- or post-training. CONCLUSION: For cervical esophageal cancer, this study suggests that special training on protocol guidelines may improve consistency in target volume definition. Explicit protocol directions are required for situations where the gross tumor is not easily visible on CT scans. This may be particularly important for multicenter clinical trials, to reduce the occurrences of protocol violations.