Efficacy and safety evaluation of stereotactic body radiation therapy based on tomotherapy for hepatocellular carcinoma北大核心CSCD

Objective: To evaluate the primary outcomes and adverse reactions of patients with hepatocellular carcinoma treated by stereotactic body radiation therapy (SBRT) using tomotherapy. Methods: From December 2012 to December 2015, Forty-six patients with hepatocellular carcinoma who received SBRT in Zhongshan Hospital Affiliated to Fudan University were enrolled. The clinical and pathological data and follow-up data of all cases were collected. The median diameter of tumors was 2.5 cm, ranging from 0.9 to 5.8 cm. All cases were performed by four-dimensional CT (4-DCT) scan and image-guided matching calibration before SBRT. Total irradiation dose ranged from 48 to 50 Gy in 5 to 10 fractions. The supportive treatments of liver protection and nutritional support were administrated during SBRT. The curative tumor response was evaluated using the modifed Response Evaluation and Criteria in Solid Tumors (mRECIST) 6 months after SBRT. The adverse reactions were evaluated using National Cancer Institute- Common Terminology Criteria for Adverse Events 3.0 (NCI-CTC 3.0). The cumulative probability of survival was calculated according to Kaplan-Meier method. Results: All cases completed SBRT. They were followed up every 3 months after treatment. Based on mRECIST, 58.7% of patients achieved complete response (CR), 32.6% achieved partial response (PR), and there were 4.3% patients with stable disease, and 2.61% patients with tumor progression. The total effective rate (CR+PR) was 91.3%. The overall survival (OS) rates at 1, 2 and 3 years were 95.4%, 75.7% and 69.9%, respectively. For the adverse reaction, only 5 cases of grade? bone marrow suppression, 2 cases of gradeII bone marrow suppression and 2 cases of grade? transaminase increase were found; no radiation-induced liver disease (RILD) occurred. Conclusion: Tomotherapy is a safe and effective treatment for the patients with unresectable hepatocellular carcinoma. So SBRT using tomotherapy is worth promoting as an alternative treatment for unresectable hepatocellular carcinoma unsuitable for standard treatment. Copyright © 2017 by TUMOR All rights reserved.     

Could helical tomotherapy do whole brain radiotherapy and radiosurgery?

Whole brain radiotherapy (WBRT) remains the standard management of breast cancer patients with brain metastases, allowing for symptomatic improvement and good local control in most patients. However, its results remain suboptimal in terms of both efficacy and toxicity. In highly selected breast cancer patients, stereotaxic radiotherapy demonstrates a very good local control with a low toxicity. With the purpose of improving the efficacy/toxicity ratio, we report the association of integrated boost with WBRT in a breast cancer patient with brain metastases. Two and a half years after completion of helical tomotherapy (HT), the patient experienced clinical and radiological complete remission of her brain disease. No delayed toxicity occurred and the patient kept her hair without need of radiosurgical procedure. The HT provided a high dosimetric homogeneity, delivering integrated radiation boosts, and avoiding critical structures involved in long-term neurological toxicity. Further assessment is required and recruitment of breast cancer patients into clinical trials is encouraged.     

螺旋断层放疗在肿瘤治疗中的应用

螺旋断层放疗是CT和直线加速器结合的放疗设备,具有360度照射、兆伏级螺旋CT(MVCT)影像引导、自适应计划等技术,可进行调强放疗、自适应放疗、立体定向外科等多种功能,适应证广泛.     

螺旋断层治疗设备多叶准直器故障分析

目的 通过对螺旋断层治疗设备二进制气动多叶准直器故障现象及处理方法的分析,总结相关维修经验,达到准确判断故障部件,缩短停机时间,提高开机率的目的。方法 对螺旋断层治疗设备48个月的多叶准直器维修情况进行统计和分析,总结出多叶准直器常见的故障部件、故障原因及处理方法。结果 在48个月内,设备共出现多叶准直器故障20次,空气压缩机11次,位置验证板4次,叶片驱动器2次,叶片缓冲阀2次,叶片位置验证杆滑脱1次。多叶准直器故障与高压气体湿度有很大关系,设备出束时间对多叶准直器部分部件使用寿命也有很大影响。结论 螺旋断层治疗设备多叶准直器结构复杂,高强度工作增加了其故障率,高压气体湿度影响设备多叶准直器的正常运行,通过总结多叶准直器维修经验可初步判断故障原因,确定故障部件,达到缩短停机时间、提高开机率的目的。     

TomoDose半导体探测器特性分析及其在Tomotherapy质控中的应用研究

目的 评估TomoDose半导体探头特性及其在检测Tomotherapy床速和Profile稳定性方面的应用,以期用其便捷、高效地对Tomotherapy进行质控。方法 结合等效水模体对TomoDose探头的剂量线性响应、每脉冲剂量响应、角度依赖性和射野大小依赖性进行测量,并与0.057 cm³A1SL指型电离室进行比较分析。以0.000 5 s为间隔预设5个组床速来检测TomoDose对床速检测的灵敏度,选取7例不同床速的临床计划数据对其进行检验。用TomoDose和等效水模体采集Tomotherapy年检中的Profile数据(测量条件和采用水箱时一致),分别在Jaw为1.0、2.5、5.0 cm状态下,在水下深度为15、50、100、150、200 mm处测量x轴向和y轴向的射线束Profile,并采用Gamma分析(2%/1 mm)方法评估TomoDose和水箱所测得的Profile数据。结果 TomoDose半导体探头和电离室在出束时间≤30 s范围内对剂量的响应呈线性;每脉冲剂量响应与电离室的差异<2%,两者响应趋势一致;其存在角度响应,在±60°范围内角度响应最大相差2.53%;Jaw=5.0 cm时不同射野大小下两者响应差异随着射野减小而增大,5.0 cm×2.5 cm时最大为0.78%。TomoDose可识别0.5 mm进床距离误差,床速检测偏差值<0.6%。对于Profile稳定性检测:在x轴向上,水下深度为15 mm时Jaw取任何值,均有γ<1;取其他值时主射野区(离轴距<200 mm的区域)内均有γ<1,射野边缘半影区(离轴距>200 mm的区域)γ较大,出现γ>1的情况。在y轴向上,3个射野宽度下所有的Profile对比结果均显示γ值在射野边缘较大,但所有情况下均有γ<1。结论 TomoDose适合对Tomotherapy进行相关质控,能够精确测量Tomotherapy的床速,能够准确监测Tomotherapy射束Profile的稳定性,并且质控过程便捷而高效。     

Assessment of extended-field radiotherapy for stage IIIC endometrial cancer using three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy

PURPOSE: To perform a dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) plans for pelvic and para-aortic RT in postoperative endometrial cancer patients; and to evaluate the integral dose (ID) received by critical structures within the radiation fields. METHODS AND MATERIALS: We selected 10 patients with Stage IIIC endometrial cancer. For each patient, three plans were created with 3D-CRT, IMRT, and HT. The IMRT and HT plans were both optimized to keep the mean dose to the planning target volume (PTV) the same as that with 3D-CRT. The dosimetry and ID for the critical structures were compared. A paired two-tailed Student t test was used for data analysis. RESULTS: Compared with the 3D-CRT plans, the IMRT plans resulted in lower IDs in the organs at risk (OARs), ranging from -3.49% to -17.59%. The HT plans showed a similar result except that the ID for the bowel increased 0.27%. The IMRT and HT plans both increased the IDs to normal tissue (see Table 1 and text for definition), pelvic bone, and spine (range, 3.31-19.7%). The IMRT and HT dosimetry showed superior PTV coverage and better OAR sparing than the 3D-CRT dosimetry. Compared directly with IMRT, HT showed similar PTV coverage, lower Ids, and a decreased dose to most OARs. CONCLUSION: Intensity-modulated RT and HT appear to achieve excellent PTV coverage and better sparing of OARs, but at the expense of increased IDs to normal tissue and skeleton. HT allows for additional improvement in dosimetry and sparing of most OARs.     

Intensity-modulated proton therapy versus helical tomotherapy in nasopharynx cancer: planning comparison and NTCP evaluation

PURPOSE: To compare intensity-modulated proton therapy (IMPT) and helical tomotherapy (HT) treatment plans for nasopharynx cancer using a simultaneous integrated boost approach. METHODS AND MATERIALS: The data from 6 patients who had previously been treated with HT were used. A three-beam IMPT technique was optimized in the Hyperion treatment planning system, simulating a "beam scanning" technique. HT was planned using the tomotherapy treatment planning system. Both techniques were optimized to simultaneously deliver 66 Gy in 30 fractions to planning target volume (PTV1; GTV and enlarged nodes) and 54 Gy to PTV2 subclinical, electively treated nodes. Normal tissue complication probability calculation was performed for the parotids and larynx. RESULTS: Very similar PTVs coverage and homogeneity of the target dose distribution for IMPT and HT were found. The conformity index was significantly lower for protons than for photons (1.19 vs. 1.42, respectively). The mean dose to the ipsilateral and contralateral parotid glands decreased by 6.4 Gy and 5.6 Gy, respectively, with IMPT. The volume of mucosa and esophagus receiving >/=20 Gy and >/=30 Gy with IMPT was significantly lower than with HT. The average volume of larynx receiving >/=50 Gy was significantly lower with HT, while for thyroid, it was comparable. The volume receiving >/=30, >/=20, and >/=10 Gy in total body volume decreased with IMPT by 14.5%, 19.4%, and 23.1%, respectively. The normal tissue complication probability for the parotid glands was significantly lower with IMPT for all sets of parameters; however, we also estimated an almost full recovery of the contralateral parotid with HT. The normal tissue complication probability for the larynx was not significantly different between the two irradiation techniques. CONCLUSION: Excellent target coverage, homogeneity within the PTVs, and sparing of the organs at risk were reached with both modalities. IMPT allows for better sparing of most organs at risk at medium-to-low doses.