体部较大肿瘤X线立体定向放射手术与适形治疗之比较

目的：评价体部X线立体定向放射手术（stereotacic radosurgey,SRS,俗称X－刀）与适形放射治疗（conformal radiation therapy,CRT)两种照射方法对于治疗直径大于5cm肿瘤的利弊。方法：对每一病例分别进行X线立体定向及适形两种治疗计划的设计，作出DVH图。结果：两种照射方法对靶区的包绕均符合临床需要，但立体定向放疗组靶区内部剂量不均匀、有热点，虽然对正常组织照射区域小，但有局部较高剂量区存在。结论：两种方法各种有利弊，但适形治疗对于减少治疗中的不良反应与并发症，明显优于前，对于直径大于7cm的肿瘤应优先选用适形治疗的照射方法。     

X线立体定向治疗体部肿瘤39例初探

1998年5月—1999年1月,我院利用Render-plan3DX线立体定向治疗系统,通过CT定位,三维治疗计划引导,对39例体部肿瘤进行了立体定向放射治疗,取得了较好的临床疗效,现报告如下。1　材料与方法1.1　临床资料　共39例,男25例,女14例,男∶女=1.79∶1,平均年龄61.2岁(25岁～83岁...     

立体定向适形照射治疗难治性肿瘤20例分析

立体定向适形照射(SCRT)在临床应用已日趋广泛,为某些常规外照射难以控制的肿瘤提供了一种补充治疗手段.现对1997年6月至1998年12月间我院治疗的该类病例进行分析,报告如下.     

X线立体定向适形放射治疗55例Ⅰ例非小细胞肺癌的临床研究

临床Ⅰ期ＮＳＣＬＣ中 ,有一部分患者由于心肺功能差或其他手术禁忌症而不宜手术 ,或患者拒绝手术。这些患者应用常规外照射五年生存率为 5 %— 30 % ,其局部失败率为40 %—70 % [1— 4] 。常规外照射在提高照射剂量上有一定限制的 ,因为随着照射剂量的增加 ,正常组织的损伤也相应增加。立体定向放射外科和立体定向放射治疗对于治疗颅内小病灶是非常有效的[5 ,6 ] 。我院自 1996年 9月将立体定向适形放射治疗技术应用于颅外 ,至今已收治 10 0 0余例患者 ,现就 5 5例不适宜手术治疗的Ⅰ期ＮＳＣＬＣ的治疗作一初步报道。材料和方法一　研究对…     

立体定向适形放射治疗体部恶性肿瘤的临床分析

目的：对62例体部恶性肿瘤实体定向适形放射治疗，并作临床分析。方法：自1997年5月至2001年5月治疗62例颅外肿瘤（89个病变部位），并进行了随访。肿瘤的临床靶体积（CTV）为0.2-254.2cm^3(平均为28.7cm^3)，计划靶体积处方剂量为3-12Gy(平均5.38Gy)，分3-10次照射。结果：治疗过程中无1例死亡。患者一般状况评分（KPS评分）：治疗前10-90分（平均60分），治疗后20-100分（平均82分）。近期疗效按实体瘤疗效标准：完全缓解（CR）6例，部分缓解(PR)34例，无变化（NC）15例，进展（PD）7例，肿瘤控制有效率为64.5%。结论：立体定向适形放射治疗颅外肿瘤有较好疗效。     

三维适形放疗与立体定向放射外科治疗脑胶质瘤初步临床分析

目的分析三维适形放疗(3DCRT)与立体定向放射外科(SRS)对于不能手术切除或拒绝手术治疗的脑胶质瘤的疗效。方法对46例不能手术或拒绝接受手术治疗的脑胶质瘤患者随机分为两组,3DCRT组24例,SRS组22例。3DCRT组施行三维适形放疗,SRS组施行立体定向放射外科治疗。结果3DCRT组患者1、2、3年生存率分别是91.7%、54.2%和8.3%,SRS组分别是80.9%、47.6%、4.8%,两组间比较无显著性差异(P=0.6487)。3DCRT组放射性脑水肿发生率为66.7%,SRS组为95.5%,两组间差异有显著性(P<0.05)。结论3DCRT与SRS放射治疗脑胶质瘤生存率相似。SRS放射性脑水肿反应明显高于3DCRT,3DCRT较SRS易为患者耐受。采用非手术疗法治疗脑胶质瘤,3DCRT可能是一种适宜的放射治疗方法。     

立体定向放射手术治疗脑转移瘤的新进展

立体定向放射手术（SRS）随着定位及计算机技术的飞速发展和大量临床经验的积累,现已扩展到治疗一定体积范围内的恶性肿瘤,尤其是脑转移瘤。恶性肿瘤脑转移的发生率一般文献报道为25％～30％,尸检发生率要比临床发生率高,约占颅内肿瘤的一半左右。脑转移患者预后差,常伴有不同程度的神经功能丧失,这成为死亡的主要原因。未治疗脑转移瘤的自然病程短,中位生存期仅1至2个月。大约60％～80％的脑转移瘤患者不适合或拒绝行外科手术,放疗成为首选治疗,但由于受正常胞组织放射耐受量的限制,放疗剂量不可能很高,而在这一方面SRS则有…     

X线立体定向适形放射治疗晚期胰腺癌

目的评价X线立体定向适形放射治疗在晚期胰腺癌治疗中的价值.方法晚期胰腺癌68例,胆肠内引流术后行立体定向适形放射治疗30例,单纯行立体定向适形放射治疗25例,单纯行胆肠内引流术13例.X线立体定向适形放射治疗采用分次照射,方法为4～5Gy/次,隔日1次,总量达40～50Gy.结果胆肠内引流术加立体定向适形放射治疗组、单纯立体定向适形放射治疗组及单纯胆肠内引流组的1、2、3年生存率分别为66.7%、20%、6.67%;44.4%、4%、0;15.39%、0、0.结论胆肠内引流术加立体定向适形放射治疗晚期胰腺癌,疗效优于单纯立体定向适形放射治疗及单纯胆肠内引流.     

立体定向适形放疗治疗脑干肿瘤疗效观察

目的: 探讨立体定向放射治疗在脑干肿瘤治疗中的疗效.方法: 对7例脑干肿瘤患者实施立体定向放射治疗,总剂量34Gy-40Gy/13-16次/4-5周.放疗后1年、5年随访.结果: 1年后复查CT/MRI,肿瘤缩小2/3者6例,1例复发.5年后复查1例患者肿瘤消失,生活恢复正常,3例死亡.结论: 立体定向精确放射治疗脑干肿瘤,可以延长患者的生存期,提高生活质量.     

Extracranial radiosurgery (stereotactic body radiation therapy) for oligometastases

Extracranial radiosurgery, also known as stereotactic body radiation therapy (SBRT), is an increasingly used method of treatment of limited cancer metastases located in a variety of organs/sites including the spine, lungs, liver, and other areas in the abdomen and pelvis. The techniques used to perform SBRT were initially modeled after intracranial radiosurgery, although considerable evolution in technique and conduct has occurred for extracranial applications. Unlike intracranial radiosurgery, SBRT requires characterization and accounting for inherent organ movement including breathing motion. Potent dose hypofractionation schedules have been used with SBRT such that the treatment is generally both ablative and convenient. Because the treatment is severely damaging to tissues within and about the target, the volume of adjacent normal tissue must be strictly minimized to avoid toxic late effects. Outcomes in various sites show very high rates of local control with toxicity mostly related to tubular tissues like the airways and bowels. With proper conduct though, SBRT can be an extremely effective treatment option for oligometastases.     

Multimodality treatment of melanoma brain metastases incorporating stereotactic radiosurgery (SRS)

BACKGROUND: Brain metastases are a frequent complication in advanced melanoma. A 3.6 to 4.1-month median survival has been reported after treatment with whole brain radiotherapy. We performed a retrospective analysis of our institutional experience of multimodality treatment utilizing linear accelerator (Linac)-based stereotactic radiosurgery (SRS). METHODS: Forty-four melanoma patients with brain metastases underwent 66 SRS treatments for 156 metastatic foci between 1999 and 2004. Patients were treated with initial SRS if or=70, but 37 patients had active systemic metastases (Recursive Partition Analysis Class 2). Survival was calculated from the time of diagnosis of brain metastases. Minimum follow-up was 1 year after SRS. The potential role of prognostic factors on survival was evaluated including age, sex, interval from initial diagnosis to brain metastases, surgical resection, addition of whole brain radiotherapy (WBRT), number of initial metastases treated, and number of SRS treatments using Cox univariate analysis. RESULTS: The median survival of melanoma patients with brain metastases was 11.1 months (95% confidence interval [CI]: 8.2-14.9 months) from diagnosis. One-year and 2-year survivals were 47.7% and 17.7%, respectively. There was no apparent effect of age or sex. Surgery or multiple stereotactic radiotherapy treatments were associated with prolonged survival. Addition of WBRT to maintain control of brain metastases in a subset of patients did not improve survival. CONCLUSIONS: Our results suggest that aggressive treatment of patients with up to 5 melanoma brain metastases including SRS appears to prolong survival. Subsequent chemotherapy or immunotherapy after SRS may have contributed to the observed outcome.     

Long-term outcome of stereotactic radiosurgery (SRS) in patients with acoustic neuromas

PURPOSE: To evaluate the effectiveness and long-term outcome of stereotactic radiosurgery (SRS) for acoustic neuromas (AN). PATIENTS AND METHODS: Between 1990 and 2001, we treated 26 patients with 27 AN with SRS. Two patients suffered from neurofibromatosis type 2. Before SRS, a subtotal or total resection had been performed in 3 and in 5 patients, respectively. For SRS, a median single dose of 13 Gy/80% isodose was applied. RESULTS: The overall actuarial 5-year and 10-year tumor control probability in all patients was 91%. Two patients developed tumor progression after SRS at 36 and 48 months. Nineteen patients (73%) were at risk of treatment-related facial nerve toxicity; of these, 1 patient developed a complete facial nerve palsy after SRS (5%). A total of 93% of the lesions treated were at risk of radiation-induced trigeminal neuralgia. Two patients (8%) developed mild dysesthesia of the trigeminal nerve after SRS. The hearing preservation rate in patients with useful hearing before SRS was 55% at 9 years. CONCLUSION: Stereotactic radiosurgery results in good local control rates of AN and the risk of cranial nerve toxicities is acceptable. As toxicity is lower with fractionated stereotactic radiotherapy, SRS should be reserved for smaller lesions.     

Comparison between prone and supine patient setup for spine stereotactic body radiosurgery

This paper investigates the dosimetric characteristics of stereotactic body radiotherapy (SBRT) treatment plans of spine patients in the prone position compared to the supine position. A feasibility study for treating spine patients in the prone position using a fiducial-less tracking method is presented. One patient with a multilevel spinal metastasis was simulated for SBRT treatment in both the supine and prone position. CT scans of the patient were acquired, and treatment plans were created using the CyberKnife? planning platform. The potential advantage of the prone setup as a function of lesion location and number of vertebral bodies involved was studied for targets extending over 1, 2 and 3 consecutive vertebral bodies in the thoracic and lumbar spine. The same process was repeated on an anthropomorphic phantom. A dose of 30 Gy in 5 fractions was prescribed to 95% of the tumor volume and the dose to the cord was limited to 25 Gy. To investigate the feasibility of a fiducial-less tracking method in the prone setup, the patient was positioned prone on the treatment table and the spine motion was monitored as a function of time. Patient movement with the respiratory cycle was reduced by means of a belly-board. Plans in the prone and supine position achieved similar tumor coverage and sparing of the critical structures immediately adjacent to the spine (such as cord and esophagus). However, the prone plans systematically resulted in a lower dose to the normal structures located in the anterior part of the body (such as heart for thoracic cases; stomach, lower gastrointestinal tract and liver for lumbar cases). In addition, prone plans resulted in a lower number of monitor units compared to supine plans.     

The role of stereotactic body radiotherapy and stereotactic radiosurgery in the re-irradiation of metastatic spinal tumors

Stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) are advanced radiotherapy delivery techniques that allow for the delivery of high-dose per fraction radiation. Advances in imaging technology and intensity modulation have allowed SRS and SBRT to be used for the treatment of tumors in close proximity to the spinal cord and cauda equina, in particular spinal metastases. While the initial treatment of spinal metastases is often conventional palliative radiotherapy, treatment failure is not uncommon, and conventional re-irradiation may not be feasible due to spinal cord tolerance. SBRT and SRS have emerged as important techniques for the treatment of spinal metastases in the proximity of previously irradiated spinal cord. Here we review the current data on the use of SBRT and SRS spinal re-irradiation, and future directions for these important treatment modalities.