A clinical comparison of patient setup and intra-fraction motion using frame-based radiosurgery versus a frameless image-guided radiosurgery system for intracranial lesions

Background and purpose

A comparison of patient positioning and intra-fraction motion using invasive frame-based radiosurgery with a frameless X-ray image-guided system utilizing a thermoplastic mask for immobilization.

Materials and methods

Overall system accuracy was determined using 57 hidden-target tests. Positioning agreement between invasive frame-based setup and image-guided (IG) setup, and intra-fraction displacement, was evaluated for 102 frame-based SRS treatments. Pre and post-treatment imaging was also acquired for 7 patients (110 treatments) immobilized with an aquaplast mask receiving fractionated IG treatment.

Results

The hidden-target tests demonstrated a mean error magnitude of 0.7 mm (SD = 0.3 mm). For SRS treatments, mean deviation between frame-based and image-guided initial positioning was 1.0 mm (SD = 0.5 mm). Fusion failures were observed among 3 patients resulting in aberrant predicted shifts. The image-guidance system detected frame slippage in one case. The mean intra-fraction shift magnitude observed for the BRW frame was 0.4 mm (SD = 0.3 mm) compared to 0.7 mm (SD = 0.5 mm) for the fractionated patients with the mask system.

Conclusions

The overall system accuracy is similar to that reported for invasive frame-based SRS. The intra-fraction motion was larger with mask-immobilization, but remains within a range appropriate for stereotactic treatment. These results support clinical implementation of frameless radiosurgery using the Novalis Body Exac-Trac system.     

恶性实体肿瘤射波刀治疗前CT引导下经皮金标植入术132例

 目的　探讨体部恶性实体肿瘤射波刀治疗前肿瘤靶区金标植入术的技术要点及并发症的处理。方法　132例体部实体恶性肿瘤在CT引导下行射波刀治疗前肿瘤靶区金标植入术,观察其并发症的发生并采取处理措施,对穿刺的安全性进行评估。结果　132例穿刺的患者中,金标植入成功率99.2 %（131／132）,16例（12.1 %） 出现穿刺部位疼痛,10例（7.6 %）出现心动过速,6例（4.5 %）出现高血压,经对症处理后均好转。68例肺癌穿刺患者中,3例出现少量气胸 ,3例出现中到大量气胸 。肝脏病灶50例穿刺患者中,1例金标游走,2例因穿刺出血导致疼痛 。结论　体部恶性实体肿瘤射波刀治疗前肿瘤靶区金标植入术是一种微创且比较安全的方法。     

Technical description, phantom accuracy, and clinical feasibility for single-session lung radiosurgery using robotic image-guided real-time respiratory tumor tracking

To describe the technological background, the accuracy, and clinical feasibility for single session lung radiosurgery using a real-time robotic system with respiratory tracking. The latest version of image-guided real-time respiratory tracking software (Synchrony, Accuray Incorporated, Sunnyvale, CA) was applied and is described. Accuracy measurements were performed using a newly designed moving phantom model. We treated 15 patients with 19 lung tumors with robotic radiosurgery (CyberKnife, Accuray) using the same treatment parameters for all patients. Ten patients had primary tumors and five had metastatic tumors. All patients underwent computed tomography-guided percutaneous placement of one fiducial directly into the tumor, and were all treated with single session radiosurgery to a dose of 24 Gy. Follow up CT scanning was performed every two months. All patients could be treated with the automated robotic technique. The respiratory tracking error was less than 1 mm and the overall shape of the dose profile was not affected by target motion and/or phase shift between fiducial and optical marker motion. Two patients required a chest tube insertion after fiducial implantation because of pneumothorax. One patient experienced nausea after treatment. No other short-term adverse reactions were found. One patient showed imaging signs of pneumonitis without a clinical correlation. Single-session radiosurgery for lung tumor tracking using the described technology is a stable, safe, and feasible concept for respiratory tracking of tumors during robotic lung radiosurgery in selected patients. Longer follow-up is needed for definitive clinical results.     

Stereotactic body frame based fractionated radiosurgery on consecutive days for primary or metastatic tumors in the lung

To evaluate the feasibility and treatment outcomes of stereotactic radiosurgery (SRS) using a stereotactic body frame (Precision Therapy™), we prospectively reviewed 34 tumors of the 28 patients with primary or metastatic intrathoracic lung tumors. Eligible patients included were nine with primary lung cancer and 19 with metastatic tumors from the lung, liver, and many other organs. A single dose of 10 Gy to the clinical target volume (CTV) was delivered to a total dose of 30–40 Gy with three to four fractions. Four to eight coplanar or non-coplanar static fields were generated to adequately cover the planning target volume (PTV) as well as to exclude the critical structures as much as possible. More than 90% of the PTV was delivered the prescribed dose in the majority of cases (average; 96%, range; 74–100%). The mean PTV was 41.4 cm³ ranging from 4.4 to 230 cm³. Set-up error was within 5 mm in all directions (X, Y, Z axis). The response was evaluated by using a chest CT and/or ¹⁸FDG-PET scans after SRS treatment, 11 patients (39%) showed complete response, 12 (43%) partial response (decrease of more than 50% of the tumor volume), and four patients showed minimally decreased tumor volume or stable disease, but one patient showed progression disease. With a median follow-up period of 18 months, a local disease progression free interval was ranging from 7 to 35 months. Although all patients developed grade one radiation pneumonitis within 3 months, none had symptomatic or serious late complications after completing SRS treatment. Given these observations, it is concluded that the stereotactic body frame based SRS is a safe and effective treatment modality for the local management of primary or metastatic lung tumors. However, the optimum total dose and fractionation schedule used should be determined after the longer follow-up of these results.     

射波刀治疗原发性肝癌的初步结果

目的 评价立体定位射波手术平台治疗肝癌患者的疗效以及初期的不良反应.方法 对17例原发性肝癌患者行射波刀治疗,共治疗肝脏病灶23个,同期治疗肝外病灶2个.肝脏病灶治疗均采用呼吸同步追踪技术,CT定位前1周植入金标到肿瘤内或肿瘤旁2 cm内.总剂量为39-52Gy,分割3-8次,处方剂量线范围为75.0%～81.0%.治疗后随访3-30个月,中位随访时间为14个月.按照世界卫生组织(WHO)的实体瘤近期疗效评价标准评定疗效,按1995年美国放射肿瘤学协作组(RTOG)和欧洲癌症治疗研究组织(EORTC)标准进行放射反应评级.结果 17例患者中,完全缓解(CR)3例,部分缓解(PR)11例,无变化(NC)3例,有效率为82.4%,临床获益率为100%.患者对治疗耐受良好,不良反应轻微.在随访期内,4例发生肝内转移,2例发生肺转移,1例发生骨转移,2例多发转移.至随访截止日期,有12例患者存活,5例死亡,17例患者的中位生存时间为14.3个月,中位无进展生存时间为12.8个月.结论 采用射波刀进行立体定向放射治疗原发性肝癌疗效显著,安全性好,但远期疗效仍需进一步随访.     

Efficacy,safety and outcome of frameless image-guided robotic radiosurgery for brain metastases after whole brain radiotherapy

Measures of treatment intensity for childhood cancer are needed in research in order to control for variability in treatments. Existing measures of treatment intensity for childhood cancers do not reflect the complexities of treatment protocols for central nervous system (CNS) tumors. This paper describes the development of the Pediatric Neuro-Oncology Rating of Treatment Intensity (PNORTI). PNORTI development occurred in three phases. Phase 1: five experts in pediatric neuro-oncology created a 5-point scale of treatment intensity and 42 pediatric neuro-oncology providers completed a three-part online questionnaire to evaluate the classification system and apply the rating system to 16 sample patients. Validity was determined by respondents classifying therapy modalities into intensity levels. Inter-rater reliability was calculated from ratings of the 16 sample patients. Phase 2: three experts revised the PNORTI based on survey results and 18 pediatric neuro-oncology providers evaluated the classification system. Phase 3: ten experts in pediatric neuro-oncology refined and finalized the PNORTI and rated 10 sample patients using the PNORTI. Agreement between median ratings of the survey respondents and criterion raters for chemotherapy intensity (r‘s?=?.82 and 1.0) and overall treatment intensity level (r‘s?=?.91 and .94) were high in Phases 1 and 2. Inter-rater reliability also was very high when using the PNORTI to classify the 16 sample patients in Phase 1 (median agreement of r?=?.93 and rICC?=?.99) and the 10 sample patients in Phase 3 (median agreement of r?=?.92 and rICC?=?.98). The PNORTI is a valid and reliable method for classifying the intensity of different treatment modalities used in pediatric neuro-oncology.     

Initial results of fractionated CyberKnife radiosurgery for uveal melanoma

Objective To evaluate prospectively local tumor control and morbidity after fractionated CyberKnife radiosurgery for uveal melanoma unsuitable for ruthenium-106 brachytherapy or local resection. Methods This study includes melanoma ≥7 mm in initial height, or juxtapapillary and/or juxtamacular tumors (height ≥3 mm; posterior tumor margin extending to within 3 mm of optic disk rim and/or fovea). Patients were excluded if they presented evidence of echographic extrascleral tumor extension, neovascular glaucoma, or any form of pretreatment or metastases at baseline. The eye was stabilized by the same ophthalmologist via peribulbar injection of 5 cc 2% lidocaine. CyberKnife radiosurgery was performed delivering a total dose of 60 Gy to the 80% or 85% isodose line in three fractions. The planning target volume (PTV) included the contrast-enhancing lesion on MRI plus a 1-mm margin (no margin on fovea site). Results Five patients with uveal melanoma were treated by this procedure. All patients had serous retinal detachment associated with the tumor. No grade ≥2 acute toxicities were observed. Eight-month follow-up revealed a decrease in tumor thickness in three patients and reattachment of the retina in four. The tumors remained stable in two eyes and an increase in retinal detachment was noted in one eye. Vision improved minimally in two eyes and remained stable in three. Conclusion CyberKnife fractionated radiosurgery seems to be a viable alternative local treatment modality in uveal melanoma with no serious acute side effects. Further follow-up is indicated.     

Dynamic CT angiography for cyberknife radiosurgery planning of intracranial arteriovenous malformations: a technical/feasibility report

Background.

Successful radiosurgery for arteriovenous malformations (AVMs) requires accurate nidus delineation in the 3D treatment planning system (TPS). The catheter biplane digital subtraction angiogram (DSA) has traditionally been the gold standard for evaluation of the AVM nidus, but its 2D nature limits its value for contouring and it cannot be imported into the Cyberknife TPS. We describe a technique for acquisition and integration of 3D dynamic CT angiograms (dCTA) into the Cyberknife TPS for intracranial AVMs and review the feasibility of using this technique in the first patient cohort.

Patients and methods.

Dynamic continuous whole brain CT images were acquired in a Toshiba 320 volume CT scanner with data reconstruction every 0.5 sec. This multi-time-point acquisition enabled us to choose the CT data-set with the clearest nidus without significant enhancement of surrounding blood vessels. This was imported to the Cyberknife TPS and co-registered with planning CT and T2 MRI (2D DSA adjacent for reference). The feasibility of using dCTA was evaluated in the first thirteen patients with outcome evaluation from patient records.

Results.

dCTA data was accurately co-registered in the Cyberknife TPS and appeared to assist in nidus contouring for all patients. Imaging modalities were complementary. 85% of patients had complete (6/13) or continuing partial nidus obliteration (5/13) at 37 months median follow-up.

Conclusions.

dCTA is a promising imaging technique that can be successfully imported into the Cyberknife TPS and appears to assist in radiosurgery nidus definition. Further study to validate its role is warranted.     

Assessment of image-guided CyberKnife<Superscript>@</Superscript> radiosurgery for metastatic spine tumors

Spinal metastases are associated with significant symptoms. From September 2005 to September 2007, 69 consecutive patients with 127 malignant spine metastatic lesions were treated at Wanfang Hospital with CyberKnife^@ (CK) radiosurgery. The radiosurgery dose ranged from 10 to 30 Gy (mean 15.5 Gy) prescribed to the 75–85% isodose line that encompassed at least 95% of the tumor volume. We used fiducials as tracking landmarks for CK treatment of the thoracic and lumbar spine. A torso anthropomorphic phantom and GafChromic MD-55 films were used to verify the accuracy of CK radiosurgery and 2D dose distribution, demonstrated high targeting accuracy with 2% average deviation of the measured dose from the estimated dose at the set-up center and less than 5% dose deviation in 2D isodose curve. Visual Analogue Scale and Oswestry Disability Index questionnaires were used to monitor functional outcome after radiosurgery. Local tumor control at 10 months was 96.8%. Mean pain scores decreased significantly from 65 to 30 after treatment (P = 0.001). Functional disability was significantly improved after treatment (P = 0.002). The most common treatment toxicities were nausea and fatigue. In conclusion, CK radiosurgery is a well-tolerated and effective treatment for spine tumors with good local tumor control and a favorable outcome on pain and functional improvement after treatment.     

鼻咽癌初程放疗后残存的分次X刀治疗初探

目的回顾性分析分次立体定向放射外科治疗鼻咽癌放疗后残存肿瘤疗效，评价其临床应用价值。方法98例鼻咽癌放疗后鼻咽局部残存患者采用分次立体定向放射外科技术推量治疗。1992年福州分期Ⅰ期2例，Ⅱ期29例，Ⅲ期53例，Ⅳa期14例。UICC1997分期Ⅰ期2例，Ⅱa期2例，Ⅱb期27例，Ⅲ期37例，Ⅳa期2l例，Ⅳb期9例。分次立体定向放射外科治疗总剂量为12～24Gy，分次剂量为4、5、6、7、8、12Gy，间隔1～7d，1～4个中心，60％～90％参考剂量线。结果完全控制95例，无法评价3例，局部控制率为97％。1、2、3、4、5、年总生存率分别为94％、86％、82％、80％、74％。1、2、3、4、5、年无瘤生存率分别为88％、82％、80％、78％、。75％。随诊超过6年的24例中，无瘤生存14例；3例随诊满8年生存3／3，8例满7年生存．4／8，13例满6年生存7／13。结论分次立体定向放射外科治疗鼻咽癌放疗后鼻咽残存肿瘤有肯定临床价值；选择合适病例能获满意疗效；剂量分割方式有个体化特点；晚期组织损伤应引起高度重视；重视肿瘤控制与周边正常组织结构损伤与修复的平衡关系。     

Acute plain anterioposterior radiograph of the pelvis is not useful in detecting fractures of iliac wing and os sacrum: A prospective study of 73 patients using CT as gold standard

Conflicting opinions exist to what extent interpreters of an acute anterioposterior (AP) radiograph of the pelvis underdiagnose pelvic injury. We have prospectively evaluated the usefulness of a plain AP radiograph of the pelvis in detecting injuries, using CT as the gold standard. Seventy‐three haemodynamically stable blunt trauma patients, who had an AP radiograph of the pelvis and an abdominopelvic CT as part of their initial imaging evaluation, were included. There were 14 women and 59 men, with a mean age of 30 (3–61) years. Two senior radiologists, with special interest in CT examinations evaluating trauma, reviewed the radiographs and a month later the CT scans, blinded and independently. Usefulness index of the plain AP radiograph of the pelvis in detecting specific injuries was calculated using CT as the gold standard. A radiograph is regarded as useful if the usefulness index is 0.35 or more. The usefulness index for a plain AP radiograph of the pelvis for detecting a fracture of iliac wing and os sacrum was 0.25 and 0.01, respectively. An acute AP radiograph of the pelvis is not useful in detecting a fracture of iliac wing or os sacrum.     

Spontaneous rupture of the renal pelvis

The object of the case report is to present a case of spontaneous rupture of the renal pelvis with no underlying pathological condition to account for the rupture, a very rare and unusual occurrence. The patient was a 46‐year‐old Korean who presented with severe left loin pain and vomiting. The diagnosis was suspected on intravenous urography and confirmed by CT. Treatment was by ureteral stenting. The patient made a complete recovery. The differential diagnosis of this condition is discussed and the literature is reviewed.     

腹盆部孤立性纤维性肿瘤的影像学表现与临床病理分析

目的 探讨发生于腹盆部的孤立性纤维性肿瘤（solitary fibrous tumor,SFr）的影像学表现.方法 回顾性分析11例发生于腹盆部的SFT患者的影像学表现及临床、病理特征.结果 11例SFT患者中,位于腹部者2例,盆腔者9例.影像学主要表现为边界清晰,较明显强化的软组织肿物,其中5例伴有囊变/黏液样改变,3例伴钙化.仅1例MR见典型纤维组织信号.结论 发生于腹盆部的SFr虽然在影像学表现上具有一些特征,但CT、超声和MR三种检查方法对SFT的检查应以发现及定位病变为主,正确的诊断应建立在充分了解SRT的影像学表现及其鉴别诊断的基础上.     

A study on the radiation tolerance of the optic nerves and chiasm after stereotactic radiosurgery

PURPOSE: To evaluate the risk of clinically significant radiation optic neuropathy (RON) for patients having stereotactic radiosurgery of benign tumors adjacent to the optic apparatus. METHODS AND MATERIALS: We reviewed the dose plans and clinical outcomes of 218 gamma knife procedures (215 patients) for tumors of the sellar and parasellar region (meningiomas, n = 122; pituitary adenomas, n = 89; craniopharyngiomas, n = 7 patients). Previous surgery or radiation therapy was performed in 156 (66%) and 24 (11%) patients, respectively. Median follow-up was 40 months (range 4-115). RESULTS: The median maximum radiation dose to the optic nerve was 10 Gy (range 0.4-16.0). Four patients (1.9%) developed RON at a median of 48 months after radiosurgery. All had prior surgery, and 3 of 4 had external beam radiotherapy (EBRT) in their management either before (n = 2) or adjuvantly (n = 1). The risk of developing a clinically significant RON was 1.1% for patients receiving 12 Gy or less. Patients receiving prior or concurrent EBRT had a greater risk of developing RON after radiosurgery (p = 0.004). CONCLUSION: RON occurred in less than 2% of our patients, despite the majority (73%) receiving more than 8 Gy to a short segment of the optic apparatus. Knowledge of the dose tolerance of these structures permits physicians to be more aggressive in treating patients with sellar or parasellar tumors, especially those with hormone-producing pituitary adenomas that appear to require higher doses to achieve biochemical remission.     

504例体部恶性实体瘤患者金标植入的探讨

目的 探讨体部恶性实体肿瘤实施射波刀治疗前肿瘤靶区金标植入术的技术要点、效果及并发症。方法 504例体部实体恶性肿瘤患者在CT引导下行射波刀治疗前肿瘤靶区金标植入术,观察植入效果及并发症。结果 504例接受金标植入的患者中,500例（99.2％）植入成功。453例肝脏穿刺患者中,6例出现金标游走。158例出现穿刺部位疼痛,3例出现心动过速,肝脏穿刺针道少量出血致术后腹痛33例;19例肺脏穿刺患者中,1例出现少量气胸,1例出现少量血胸。结论 体部恶性实体肿瘤实施射波刀治疗前肿瘤靶区金标植入术是一种微创且相对比较安全的方法。     

Comparison of three strategies to delineate the bowel for whole pelvis IMRT of prostate cancer

PURPOSE: To compare three different contouring approaches of the bowel before and during whole pelvis IMRT of localized prostate cancer. MATERIALS: Nine patients were randomly selected among those treated for localized prostate cancer at UTMB from March 2004 to August 2006. On the planning CT, besides the usual organs at risk (OAR), for each patient we contoured the bowel according to three different definitions: each bowel segment ('BS'); 'BS+1', BS uniformly expanded by 1cm; intestinal cavity ('IC') or the 'container' of the bowel loops up to the pelvic/abdominal walls. For each patient we generated three rival plans each considering a different bowel definition, otherwise identical. Provided that the same target coverage and other OAR spare had been achieved, plans were compared for their ability to minimize bowel dose at planning. Furthermore, after co-registering 6 weekly CT to the initial planning CT for each patient, we investigated which of the three definitions would allow the best bowel protection also during treatment. RESULTS: All definitions provided a very similar average bowel DVH at planning. During treatment BS allowed an average approximately 20 cc more of bowel to receive at least 45 Gy over BS+1 and IC (p=0.008 and 0.029, respectively); on the contrary bowel V45 between IC and BS+1 were not significantly different (p=0.65). CONCLUSION: A definition that takes into account internal organ motion is warranted to maximize bowel protection during treatment.     

Stereotactic radiosurgery for pituitary adenomas: a comprehensive review of indications,techniques and long-term results using the Gamma Knife

Object This study reviews the long-term clinical results of stereotactic radiosurgery in the treatment of pituitary adenoma patients. Methods We reviewed the outcomes of 298 patients who underwent Gamma Knife radiosurgery for recurrent or residual pituitary adenomas. These results are compared to other contemporary radiosurgical series. Results Pituitary tumors are well-suited for radiosurgery, since radiation can be focused on a well circumscribed region, while adjacent neural structures in the suprasellar and parasellar regions are spared. The overall rate of volume reduction following stereotactic radiosurgery is 85% for non-secretory adenomas that are followed for more than 1-year. The rates of hormonal normalization in patients with hypersecretory adenomas can vary considerably, and tends to be higher in patients with Cushing’s Disease and acromegaly (remission rate of approximately 53% and 54%, respectively) when compared with patients who have prolactinomas (24% remission) and Nelson’s syndrome (29%) remission. Advances in dose delivery and modulation of adenoma cells at the time of radiosurgery may further improve results. Conclusions Although the effectiveness of radiosurgery varies considerably depending on the adenoma histopathology, volume, and radiation dose, most studies indicate that radiosurgery when combined with microsurgery is effective in controlling pituitary adenoma growth and hormone hypersecretion. Long-term follow-up is essential to determine the rate of endocrinopathy, visual dysfunction, hormonal recurrence, and adenoma volume control.