Expert Consensus on the Treatment of Antiangiogenic Agents for Radiation Brain Necrosis / 中国肺癌杂志

Vascular damage is followed by vascular endothelial growth factor (VEGF) expression at high levels, which is an important mechanism for cerebral radiation necrosis (CRN) development. Antiangiogenic agents (Bevacizumab) alleviates brain edema symptoms caused by CRN through inhibiting VEGF and acting on vascular tissue around the brain necrosis area. Many studies have confirmed that Bevacizumab effectively relieves symptoms caused by brain necrosis, improves patients' performance status and brain necrosis imaging. Considering that the efficacy of antiangiogenic therapy is mainly related to the duration of drug action, low-dose antiangiogenic agents can achieve favorable efficacy. Prevention is the best treatment. The occurrence of CRN is associated with tumor-related factors and treatment-related factors. By controlling these factors, CRN can be effectively prevented.
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The feasibility study of generalization of knowledge-based planning for cervical cancer / 中华放射医学与防护杂志

Objective:To design a knowledge-based cervical cancer planning model and apply it to cases of endometrial cancer and rectal cancer in order to explore the generalization of the model.Methods:A total of 179 cases of pelvic regions with different prescribed doses of dual-arc volumetric modulated arc therapy clinical plans were collected, of which 99 cases of cervical cancer clinical plans with a prescribed dose of 50.4 Gy were used as the training set to establish the RapidPlan model, and the remaining clinical plans were divided into 4 validation groups with 20 cases in each group. The clinical plans for cervical cancer and endometrial cancer with a prescription dose of 50.4 Gy were named groups A and B, while the clinical plan for endometrial cancer and rectal cancer with a prescription dose of 45 Gy were named groups C and D. The model was used to redesign the clinical plans in the 4 groups and the automatic plans were obtained. The planning target volume (PTV) and organ at risk (OAR) dosimetry parameters were compared between automatic plans and clinical plans.Results:The conformity index (CI) of the automatic plans in the A, B, C, and D groups were equivalent to that of the clinical plans ( P>0.05). The homogeneity index (HI) and D2% of the automatic plans in groups A, B, and C were all lower than those in clinical plans(HI, Z=-3.248, -3.360, -2.329, P<0.05; D2%, Z=-2.987, -3.397, -2.442, P<0.05). The HI and D2% of the automatic plans in group D were similar those in the clinical plans ( P>0.05). While ensuring the PTV coverage, the average value of OAR dosimetry parameters in all automatic plans groups were lower than that of the clinical plans. Conclusions:The RapidPlan model established by the cervical cancer clinical plans can complete the automatic plan design for endometrial cancer and rectal cancer under different prescription doses, which preliminarily proves the possibility of the generalization of the RapidPlan model.

Effect of Halo-Vest on dose distribution of radiotherapy for primary cervical spine malignant tumors / 中华放射医学与防护杂志

Objective:To investigate the effect of Halo-Vest on the dose distribution of different radiotherapy techniques for primary cervical spine malignant tumors.Methods:Ten patients with primary cervical spine malignancies who underwent radiotherapy after Halo-Vest surgery were retrospectively studied. The IMRT and VMAT plans were designed on the contoured CT images including Halo-Vest delineations using Monaco planning system. The IMRT and VMAT plans with the same field parameters were duplicated to the CT images without the Halo-Vest delineations, and the dose distribution was recalculated. The dose distribution of the target, organs at risk and normal tissues was analyzed and compared for the plans with and without the Halo-Vest delineation.Results:For most dosimetric parameters of VMAT plans, the mean deviations induced by the Halo-Vest were less than 1%, except for PGTV 107%. Without Halo-Vest delineation, the mean maximum dose of spinal cord and spinal cord-PRV increased by 0.38 Gy and 0.42 Gy ( Z=-2.803, -2.803, P<0.05), respectively. The mean Dmean of spinal cord and spinal cord PRV increased by 0.35 Gy and 0.37 Gy, respectively ( Z=-2.703, -2.701, P<0.05). The maximum deviation observed in the mean V5, V30, and Dmean of mucosa, thyroid, parotid gland, mandible, mandibular joint, and normal tissues was 0.74%. For IMRT plans, larger dosimetric deviations than VMAT plans were observed in PTV and PGTV, most of which were more than 1.0% and the maximum deviation was 4.55%. The absence of Halo-Vest delineation increased the mean maximum dose of spinal cord and spinal cord-PRV by 0.48 Gy and 0.59 Gy ( P>0.05), respectively. The mean Dmean of spinal cord and spinal cord PRV increased by 0.57 Gy and 0.59 Gy, respectively ( Z=-2.293, -2.293, P<0.05). The maximum deviation of other organs at risk was 1.98%. Conclusions:There are no clinically significant dose differences for VMAT planning with or without Halo-Vest delineation on the CT images. But the dosimetric impact of absent or partial Halo-Vest delineation on IMRT planning is relatively large and should be considered.

Treatment for Brain Metastases from EGFR Mutations NSCLC Patients: How Should We Choose in Clinical Practice? / 中国肺癌杂志

Brain metastasis of epidermal growth factor receptor (EGFR) sensitive mutations is a hot and difficult point in targeted era of non-small cell lung cancer (NSCLC) treatment, meanwhile it is also the central issue of controversy in the field of lung cancer treatment. Different results of different studies and different understanding of different disciplines, this field of treatment has been accompanied by different voices, patients without clinical symptoms can use targeted therapy first, and then start local radiotherapy with clinical symptoms or disease progression. It is a major model of the medical oncology. That is to say, taking symptoms and progress as indication and standard of local treatment intervention. In the absence of symptoms, local radiotherapy may increase patients' pain, which belongs to overtreatment. However, the perspective of radiotherapy is that brain metastases need to be treated clinically as early as possible, if not, it may affect the survival of patients. Early treatment of local lesions and increasing the depth of treatment are helpful to prolong the survival time of patients. This article refers to relevant literatures and summarizes the discussion from the perspective of pursuing the truth of disease treatment and problem solving in order to provide reference for patients' clinical practice.

Progress of separation surgery in metastatic spine disease / 中华骨科杂志

Spinal metastases may cause pain,pathological fracture and/or neurological symptoms.The most common treatment of spinal metastases is conservative therapy.Surgical intervention is necessary when there are pathological and/or neurological deficits.Total en bloc spondylectomy (TES) has lower local recurrence rate and may be applicable to a patient with single metastatic tumor and a long survival expectancy,While debulking surgery is less risky and higher recurrence rate.Conventional radiotherapy is a kind of effective supplement to reduce the local recurrence rate in spinal metastases.However,the local dose is often failed to reach the effective dose because of the close connection of tumor and spinal cord and it is less effective for relatively radioresistant histologies.With the development of radiotherapy technology,spinal radiotherapy has become increasingly accurate to avoid of spinal cord injury.In addition,conventional radioresistant tumors has become treatable with high-dose stereotactic body radiotherapy (SBRT).At the same time,SBRT is also an important basis for the implementation of separation surgery of spinal metastases.Separation surgery is to separate the tumor and dura and achieve circumferential decompression and stabilization through posterior approach.As a result,a high-dose SBRT can be performed because of the small interspace to protect the spinal cord,which greatly reduces the local recurrence rate.Compared with TES,separation surgery combined with high-dose radiotherapy not only reduces the difficulty of surgery,but also has a good local control rate,which is a relatively "minimally invasive" strategy.Separation surgery is particularly suitable for patients with high-grade epidural spinal cord compression and moderately sensitive or insensitive to radiotherapy.Although the concept of separation surgery has been proposed for several years,only a few applications have been reported in foreign literature and fewer in domestic literature.This article aims to summarize the relevant concepts and clinical applications of separation surgery in spine metastases and to provide a reference for the treatment of spinal metastases.

Utilization rate of gold fiducial markers and reasons for abandonment in CyberKnife stereotactic body radiation therapy / 中华放射肿瘤学杂志

Objective To investigate the utilization rate of gold fiducial markers and reasons for abandonment of gold fiducial markers in the CyberKnife VSI System, and to provide reference data for implantation of gold fiducial markers and radiotherapy planning. Methods From March to August,2017,a total of 47 patients had gold fiducial markers implanted or pasted. In those patients, 42 patients had gold fiducial markers implanted,including 32 receiving computed tomography(CT)-guided 3D-printing coplanar template assisted implantation, 1 receiving CT-guided 3D-printing non-coplanar template assisted implantation,1 receiving CT-guided implantation,and 8 receiving ultrasound-guided implantation. A total of 44 patients received the CyberKnife treatment, including 2 patients who failed to use gold fiducial markers and were treated with spine tracking instead and 3 patients missing the treatment for other reasons. The numbers of utilized and abandoned gold fiducial markers were recorded for calculation of the utilization and abandonment rates. The reasons for abandonment of gold fiducial markers were analyzed and classified. Results A total of 134 gold fiducial markers were implanted into or pasted to the 44 patients.In all the gold fiducial markers, 111 were utilized and 23 abandoned, yielding a utilization rate of 82.8% and an abandonment rate of 17.2%.The reasons for abandonment of gold fiducial markers included large rigidity error(26.1%), unqualified implanted fold fiducial markers(17.4%), displacement of gold fiducial markers(26.1%), and others(30.4%). Conclusions Compared with the CT-guided or ultrasound-guided implantation of gold fiducial markers, the CT-guided 3D-printing coplanar or non-coplanar template assisted implantation of gold fiducial markers requires only two puncture needles for each implantation and implants two gold fiducial markers by a single needle,which reduces the number of puncture needles,risk of puncture-induced injury,and incidence of complications after implantation. Not all the gold fiducial markers implanted by a variety of ways will be utilized. Some gold fiducial markers will be abandoned for different reasons,which should be taken into account during implantation of gold fiducial markers.

Clinical efficacy of CyberKnife stereotactic body radiation therapy for hepatic hilar cancer / 中华放射肿瘤学杂志

Objective To evaluate the efficacy and safety of CyberKnife stereotactic body radiation therapy (SBRT) in the treatment of hepatic hilar cancer.Methods A retrospective study was performed on the clinical data of 36 patients with hepatic hilar cancer who were admitted to our hospital and treated with CyberKnife SBRT from 2009 to 2015.In the 36 patients,37 lesions were found with tumor diameters ranging from 1.5 to 5.5 mm (median diameter 3 cm).The Synchrony respiratory tracking system was used for 21 lesions in 20 patients,while the XSight spinal tracking system was used for 16 lesions in 16 patients.Local progression was evaluated based on contrast-enhanced computed tomography and/or magnetic resonance imaging.The Kaplan-Meier method was used to calculate local control (LC) and overall survival (OS) rates,and the log-rank test was used for survival comparison and univariate prognostic analysis.Results The median follow-up time was 12.7 months.The 1-and 2-year postoperative LC rates were 90％ and 76％,respectively.The 1-year OS and progression-free survival (PFS) rates were 63％ and 39％,respectively.The median OS and PFS times were 15.2 and 10 months,respectively.The incidence of grade 3 adverse reactions was 11％.Conclusions The CyberKnife SBRT is a safe and effective way to treat hepatic hilar cancer.

Clinical observation on the treatment efficacy of Cyberknife for iliac lymph node metastasis / 中华放射医学与防护杂志

Objective To evaluate the response rate and efficacy of Cyberknife in the treatment of iliac lymph node metastases (ILNM).Methods Twenty-two patients with 27 ILNM were treated by Cyberknife from May 2010 to May 2016.Tumor volume range from 0.88 to 125.66 cm3 (median 18.87 cm3).The total doses ranged from 21 to 51 Gy (median 39 Gy) and biological effective doses from 35.7 to 100 Gy (median 72.6 Gy) in 3-8 fractions (median 5).Sixty-four percent to eighty-two percent (median 72％) isodose line covered planning target.The survival rates were calculated by Kaplan-Meier method and compared with Log-rank test.Results Follow-up time ranged from 8 to 97 months (median 33 months).The complete response,partial response,stable disease and progression disease rates were 37％,48％,7.5％,48％,respectively.In addition,effective rate was 92.5％.Overall survival range from 4 to 68 months (median 21 months).The 1-,2-,3-year local control rate was all 90.6％ and the survival rates were 78.8％,60.6％ and 43.3％,respectively.Adverse reactions after treatment were gastrointestinal reactions such as nausea,vomiting,fatigue.The chemotherapy before Cyberknife helped to improve overall survival.The patients with backache or edema of lower extremity got rapid relief after treatment.Conclusion The treatment of ILNM with Cyberknife has provided a high response rate with minimal side effects.Cyberknife is a safe and effective local treatment method for ILNM.

Biologically effective dose calculation of radioactive seed implantation brachytherapy and its clinical application / 中华放射医学与防护杂志

Objective To establish a model for the calculation of biologically effective dose (BED) and EQD2 (Equivalent dose in 2 Gy fractions) in radioactive seed implantation brachytherapy.Methods The BED formula for EBRT(external beam radiotherapy) and for continuous low dose-rate irradiation established under the L-Q model were introduced.The EDQ2 formula for the continuous low dose-rate irradiation (radioactive seed implantation) was established according to the definition of EQD2 and the formula of BED.The α/β values of common tissues and the Tr 1/2 values reported in the literature were summarized.The EDQ2 formula were further simplified by using the actual values.The empirical formula of EDQ2 for early reaction tissues and late reaction tissues were proposed,named as Wang-Peng empirical formula.EDQ2≈ (10/12) D (Wang-Peng Formula 1) was fit for early response tissue,and EDQ2≈ D/2 (Wang-Peng Formula 2) for late reaction tissues.Further examples on the clinical applications of the proposed formula were given,including primary lung cancer,supraclavicular lymph node metastasis of esophageal cancer and celic lymph node metastasis of cervical carcinoma.Results According to the Wang-Peng empirical formula,the EDQ2 of the late reaction tissue adjacent to the tumor was only about half that of the tumor tissue,so the radioactive seed implantation brachytherapy naturally protected the late reaction tissue by the biological equivalent dose.The actual calculation,showed that the empirical formula of early reaction tissue was more accurate,but the empirical formula of late reaction orgtissue was less inaccurate and could only be roughly estimated.Conclusions The BED calculation formula introduced here and the set of EQD2 calculation formula and Wang-Peng empirical formula established here were theoretically feasible and could be used for the conversion and superposition between the physical dose of radioactive seed implantation brachytherapy and the external irradiation dose.But it should be careful to apply the formula,pay attention to the default conditions,and carefully interpret the calculated results.

A study of influencing factors and predictors for radiation encephalic necrosis after CyberKnife radiotherapy / 中华放射肿瘤学杂志

Objective To investigate the influencing factors and predictors for radiation encephalic necrosis after CyberKnife radiotherapy.Methods Ninety-four patients (104 targets) with primary or metastatic intracranial tumors who were treated with CyberKnife radiotherapy from 2006 to 2011 were retrospectively analyzed.All surgeries adopted skull tracking modes with a dose of 12-45 Gy in 1-8 fractions prescribed to 60％-87％ isodose line.Radiation encephalic necrosis was determined by imaging or pathological examination.Logistic regression analysis was used to analyze the relationship between radiation encephalic necrosis and factors including diabetes,cardio-cerebrovascular diseases,target volume,isodose line,prescribed dose,number of fractions,combination with whole-brain irradiation (WBI),and biologically equivalent dose (BED).Predictability and critical threshold of all influencing factors for radiation encephalic necrosis were determined by the receiver operating characteristic (ROC) curve.Results Twelve targets (11.54％) had radiation encephalic necrosis.According to the result of logistic regression analysis,BED,combination with WBI,and number of fractions were influencing factors for radiation encephalic necrosis.In the ROC curves,the areas under curves for the above three factors were 0.892 ± 0.034,0.650± 0.072,and 0.712 ± 0.064,respectively,indicating that only BED can well predict radiation encephalic necrosis after CyberKnife radiotherapy with a dose threshold of ＞ 7410 cGy.Conclusions BED,combination with WBI,and number of fractions are influencing factors for radiation encephalic necrosis.BED is the best predictor of radiation encephalic necrosis with a dose threshold of ＞ 7 410 cGy.

Clinical efficacy of CyberKnife radiotherapy for locally advanced pancreatic carcinoma / 中华放射肿瘤学杂志

Objective To assess the efficacy and safety of CyberKnife radiotherapy in the treatment of locally advanced pancreatic carcinoma. Methods The data of 59 patients with locally advanced pancreatic carcinoma who were treated with CyberKnife radiotherapy from 2006 to 2014 were retrospectively analyzed. The tumor volume ranged from 13?? 0 cm3 to 125?? 1 cm3 with a median value of 27?? 1 cm3 . A dose of 35?50 Gy (median value= 45 Gy) in 3?8 fractions (median value = 5 fractions) was prescribed. The tumor progression was evaluated based on computed tomography. The overall survival (OS) and local progression?free survival ( LPFS) rates were calculated using the Kaplan?Meier method. Results The 1?and 2?year sample sizes were 26 and 17, respectively. The 1?and 2?year OS rates were 54% and 35%, respectively, while the 1?and 2?year LPFS rates were 91% and 70%, respectively. The median OS and LPFS times were 12?? 5 and 10?? 9 months, respectively. The overall incidence of grade 1?2 acute and late gastrointestinal toxicity was 61%. One patient with grade 3 late gastrointestinal toxicity had incomplete intestinal obstruction. Conclusions CyberKnife radiotherapy can achieve excellent treatment outcomes and mild complications in the treatment of locally advanced pancreatic carcinoma.

Robotic stereotactic irradiation and reirradiation for spinal metastases: safety and efficacy assessment / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Spine is the most common site of bone metastases in patients with cancer. Conventional external beam radiotherapy lacks precision to allow delivery of large fraction radiation but simultaneously limit the dose to spinal cord. The purpose of this study was to evaluate the safety and efficacy of CyberKnife(®) radiation therapy for spinal metastases.</p><p><b>METHODS</b>Seventy-three lesions in 62 patients treated with CyberKnife radiotherapy from September 2006 to June 2010 for spinal metastases were retrospectively reviewed. Thirteen tumors in 12 patients had received prior radiation. Patients were followed clinically and radiographically for at least 12 months or until death. In all patients, the spinal cord and thecal sac were contoured for dose-volume constraints, and maximum doses to 0.1, 0.5, 1, 2, and 5-ml volumes were analyzed.</p><p><b>RESULTS</b>Using the CyberKnife System, 20-48 Gy in one to five fractions for unirradiated patients, and 21-38 Gy in one to five fractions for the previously irradiatied patients, were delivered. Median 2-Gy normalized Biological Equvalent Dose (nBED) of unirradiated targets and irradiated targets were 49.6 Gy10/2 (range, 31.25-74.8 Gy10/2) and 46.9 Gy10/2 (range, 29.8-66 Gy10/2), respectively. With a median follow-up of 9.4 months (range, 2.5-45 months), twenty-nine patients (46.7%) were alive, whereas the others died of progressive disease. Fifty-six patients (93.3%) reported complete or partial reduction of pain after CyberKnife radiotherapy at one-month follow-up, 17 patients (28.3%) reported some degree of pain relief after first fraction of the treatment course. Two patients experienced local recurrence at fifth and ninth months post-radiotherapy. Median maximum nBED for spinal cord and thecal sac of naive targets were 68.6 Gy2/2 (range, 8.3-154.5 Gy2/2) and 83.5 Gy2/2 (range, 10.5-180.5 Gy2/2), respectively. Median maximum nBED for spinal cord and thecal sac for the re-irradiated targets were 58.6 Gy2/2 (range, 17.7-140 Gy2/2) and 70.5 Gy2/2 (range, 21.7-141.3 Gy2/2), respectively. No patient developed radiation related myelopathy during the follow-up period.</p><p><b>CONCLUSION</b>Cyberknife radiotherapy is clinically effective and safe for spinal metastases, even in previously irradiated patients.</p>

Evaluation of extra absorbed dose generated by image guided system of the Cyberknife / 中华放射肿瘤学杂志

Objective To evaluate quantitatively the extra absorbed dose generated by image guided system of the Cyberknife.Methods The exposure parameters and the average frequency of images acquisition during the treatments with G3 Cyberknife in 300 cases with various tumor locations and tracking modes were collected for analysis ;The measurements of the absorbed doses in the phantom with 5 points after single exposure generated by image guided system in various exposure parameters were performed with equipment of phantom CIRS Model 002LFC and 002 PRA with ion chamber PTW30010 included.Based on the data we collected andmeasured,the conclusion of how much extra absorbed dose generated by image guided system of Cyberknife the patients received during Cyberknife treatments was drawn.Results With an average fractions of 3.94(the median was 4),the average exposure frequency was 36.5 times for static tracking per patient per fraction,while it was 49.2 times for dynamic tracking.The experimental results with various exposure parameters,positions and tissue densities showed that the minimum absorbed dose after single exposure was 0.5 μGy,while the maximum was 385 μGy.Conclusions The image guided system of the Cyberknife can induce quite low absorbed dose in patient,while providing all three types of image guided function.

Impacts of different tracking methods on short-term therapeutic effect of cyberknife in treatment of lung cancer / 中华放射肿瘤学杂志

Objective To investigate the impacts of fiducial tracking and X-sight tracking on the short-term therapeutic effect of cybernikife in the treatment of lung cancer.Methods Retrospective analysis was performed on 64 lung cancer patients (72 lesions),including 40 primary tumor patients (41 lesions) and 24 metastatic tumor patients (31 lesions),who were treated with cyberknife.Fiducial tracking was used for 45 lesions,while X-sight tracking was used for 27 lesions.The planning target volume was covered by 70％-94％ (median 80％) isodose contour.The irradiation dose was 60 Gy/3 fractions.The relationship between short-term therapeutic effect and tracking method was determined.Results Overall,the lesions undergoing fiducial tracking showed significantly higher response rate than those undergoing X-sight tracking (93％ vs.74％,x2 =6.84,P=0.033),and so was in lower lung lesions (15％ vs.7％,x2 ＝7.18,P=0.028).But the two tracking methods achieved similar effects in upper lung lesions (28％ vs.12％,x2 =2.36,P =0.310).In the lesions with treatment volumes smaller than 15 cm3,the fiducial tracking achieved significantly higher response rate than the X-sight tracking (25 ％ vs.12％,x2 =6.53,P =0.038),but the two tracking methods achieved similar effects in the lesions with treatment volumes not smaller than 15 cm3 (17％ vs 8％,x2 =1.57,P =0.460).Overall,the lesions undergoing X-sight tracking had significantly highertreatment failure rate than fiducial tracking (1 9 ％ vs.2 ％,x2 =6.33,P =0.021).Conclusions Different tracking methods may lead to different therapeutic effects of cyberknife in the treatment of lung cancer,which are related to lesion location and treatment volume.

Value of local progression-free survival for evaluating local outcome of peripheral lung cancer treated by cyberknife / 中华放射肿瘤学杂志

Objective To investigate the value of local progression-free survival (LPFS) for evaluating the local long-term outcome of peripheral lung cancer treated by cyberknife.Methods Retrospective analysis was performed on the clinical records of 81 cyberknife-treated lung cancer patients (90 foci),including 43 primary lung cancer patients (43 foci) and 38 metastatic lung cancer patients (47 foci).Of all the patients,58(63 foci) were treated at a dose of 60 Gy/3 fractions (20 Gy/fraction),and 23 (27 foci) at a dose of 54 Gy/3 fractions (18 Gy/fraction).The short-term treatment outcome and LPFS were used as the indices for observation;a logistic regression was used for analyzing the predictive value of LPFS for local long-term treatment outcome.Results After the evaluation of short-term treatment outcome,63％ of all the foci needed further evaluation.As the follow-up lasted,the number of foci which needed further evaluation decreased,most rapidly during 0.5-2 years after treatment.Re-evaluation results had predictive value for the treatment outcome in the subsequent follow-up,but the predictive value declined as the follow-up lasted.Conclusions LPFS is a recommendable index for evaluating the local outcome of primary or metastatic lung cancer treated by cyberknife,and it also has predicative value for local long-term treatment outcome.

Clinical observation on the therapeutic efficacy of cyberknife for primary or metastastic retroperitoneal tumors / 中华放射肿瘤学杂志

ObjectiveTo evaluate the early response rate and radiation toxicity of cyberknife in the treatment of primary or metastasticretroperitoneal tumors.MethodsTwenty-eightpatientswith retroperitoneal tumors were treated with cyberknife.The total doses were 2000-6000 cGy ( median 4500 cGy) and biological effective doses were 3750-10080 cGy (median 7680 cGy) in 2-10 fractions (median 5).Of all patients,3 received three dimensional conformal radiotherapy (3DCRT) or intensity modulated radiotherapy (IMRT) boost,1 was treated as second-course radiotherapy,and others were treated with cyberknife only.The survival rates were calculated by Kaplan-Meier method and compared with Logrank test.ResultsThe complete response,partial response,stable disease and progression disease rates were 43％(12/28),6％ ( 10/28),18％ ( 5/28 ),4％ ( 1/28 ),respectively.The overall response rate was 96％.The number of patients who were followed up more than 1,2,3 years were 17,9,7,respectively.The 1-,2-and 3-year local control rates were 92％,86％ and 86％,respectively.The 1-,2-and 3-year overall survival rates were 60％,49％ and 49％,respectively.The difference between local progression-free survival and overall survival was not significant ( median 9.5 and 12.0 months,x2 =0.17,P =0.680).Moreover,if the patients did not have metastasis elsewhere and local treatment was effective,there was no significant difference between local progression-free survival and progression free survival (median 17 and 11 months,x2 =0.13,P=0.720).Acute radiation-induced side effects (≥ 2 grade) such as fatigue,anorexia,nausea,vomiting and epigastric discomfort occurred in 9,9,7,7 and 2 patients,respectively.Intestinal stenosis of 1 grade occurred in 1 patient.Conclusions Radiotherapy for retroperitoneal tumors with cyberknife has provided a high response rate with minimal side effects.It is a safe and effective local treatment method for retroperitoneal tumors.

Results and prognostic factors of CyberKnife for lung metastasis / 中华放射肿瘤学杂志

ObjectiveTo investigate the effectiveness and toxicity of CyberKnife in the treatment of lung metastases.MethodsTreatment details and outcomes were reviewed for 93 targets of 48 histologically verified patients treated by CyberKnife at the CyberKnife Center of Tianjin between September 2006 and June 2010.The median tumor volume was 6.0(0.2 - 135.2) cm3,the median biological equivalent dose was 140.8(53 - 180) cGy (α/β =10),the median fraction was 3(1-7) times and the median isodose line was 81％ (71％-91％ ).ResultsThe rate of follow-up is 96％.33 cases were followed up for more than 2years.The effective rate was 90.3％.Two targets of 2 patients locally progressed.The 1-and 2-year local control rates,overall survival (OS) rates and progression-free survival (PFS) rates were 98％ and 98％,83％ and 63％,and 64％ and 37％,respectively.Univariate analyses showed that age older than 60 versus ≤60 years tended to be predictor for PFS ( x2 =3.45,P =0.063 ) ;The PFS of patients who had single lesion was better than patients with multiple lesions ( x2 =4.49,P =0.034 ) ; patients with disease-free interval longer than 18 months had better OS ( x2 =6.50,P =0.011 ).Five patients were reported to experience treatment-related grade 1 radiation pulmonary injury,and one each for subcutaneous fibrosis with pigmentation,grade 2 and grade 3 adverse event.ConclusionsFor patients with lung metastatic lesion,CyberKnife is an effective option with high local control rate and little acute reaction.The long-term outcome and toxicity need further study.

Enhancement of radiation sensitivity by erlotinib and celecoxib in A549 human lung cancer cell line / 中华放射医学与防护杂志

Objective To investigate the role of epidermal growth factor receptor and cyclooxygenase-2 pathways in the erlotinib and celecoxib enhanced radiation sensitivity in A549 human lung cancer cell line. Methods IC20 of erlotinib and celecoxibon in A549 human lung cancer cells was measured by MTT assay,Clonogenic assays were used to evaluate the antitumor effects of the drugs and Xirradiation.Flow cytometry was used to assess the apoptosis and cell cycle alteration,and Western blot was used for the detection of Akt and phospho-Akt.Results Both erlotinib and celecoxib could inhibit the proliferation of A549 cells in vitro in a dose-dependent manner and their values of IC20 were (5.15 ± 0.14)and (40.32 ± 1.26) μmol/L,respectively. For radiation survival,the values of Dq,Do,SF2 of the combination of two drugs were lower than those of either drug ( t =6.62,P ＜ 0.05).The SER of celecoxib,erlotinib and their combination were 1.299,1.503 and 2.217,respectively.Flow cytometry assay showed that both celecoxib and erlotinib could enhance radiation-induced G0/G1 arrest,reduce the cell numbmer in S phase,and enhance radiation-induced apoptosis,especially for the combination of drugs.Western blot assay showed that the expressions of Akt protein were similar in all groups.However,pAkt expression was suppresssed by erlotinib and celecoxib,but promoted by radiation.pAkt had the lowest expression in the radiated cells with the treatment of two drugs ( t =4.89,P ＜ 0.05 ).Conclusions The edotinib and/or celecoxib could enhance radiosensitivity probably by increasing cell apoptosis and reducing the number of Sphase cells with low radiosensitivity.

Gefitinib at different administration time in radiosensitizing lung adenocarcinoma cells in vitro / 中华放射肿瘤学杂志

Objective To investigate the radiosensitizing effects of gefitinib at different administration time. Methods Gefitinib was administered to A549 lung cancer cells in three different ways (method 1, 24 h before irradiation ;method 2, upon irradiation and method 3, 24 h after irradiation). Cell-surviving rates were evaluated by the colony-forming assays. Cell apoptnsis and cell-cycle distributions were detected by the flow cytometry (FCM). Protein expression of p21, Cdc25c, Bcl-2, Bax, Rad51 and phosphorylated DNA - PKcs (phnspho - DNA - PK) were measured with the Western blot analysis. Results The sensitizing effect ratio (ratio of D_0 value) was 2.23, 1.51 and 1.30 with method 1, 2 and 3, respectively. A higher apoptosis rate and more G_2/M phase arrest were observed with method 1 when compare with method 2 or 3. With the similar tendency, the protein level of p21, Cdc25c, Bcl-2, Bax, RadSl and phospho-DNA-PK changed distinctly. Conclusions Radiosensitizing effects are obtained in all three methods, with gefitinib delivered before irradiation being the best.

EGFR antibody radiosensitivity enhancement on CL187 cancer cells after continous low dose rate irradiation / 中华放射医学与防护杂志

Objective To investigate the radiosensitivity enhancement on CL187 cancer cell lines after continous low-dose-rate irradiation of 125I seeds blocked by EGFR antibody.Methods There were control group,the irradiation or plus EGFR antibody group,with 3 samples in each group.Clongenic assay was used to detect the survival of cells.The cell cycle distribution and apoptosis were analyzed by flow cytometry.Results The survival fraction of CL187 cells were lower after blocked by EGFR antibody at the same dose irradiation.The SER were 1.34,1.59 and 1.98 when the antibody concentration were 2,5 and 10 nmol/L,respectively.The irradiation plus antibody led to more apoptosis(39.86%±4.38%)of CL187 cells than the irradiation (21.57%±2.97%)plused antibody(12.49%±1.59%)worked alone.Comparison of the low dose rate irradiation related to G2/M cell cycle arrest(46.41%±4.48%),More G1 cell cycle arrest(84.51%±3.42%)walked together along with the EGFR antibody.Conclusions EGFR antibody could enhance the cell radiosensitivity after continuous low-dose-rate.irradiation.The cell cycle redistribution and apoptosis might be the main mechanism of the radiosensitivity enhancement.