目的:探讨及评价不同准直器(Fixed/Iris)的选择对治疗计划剂量学特点的影响。方法:选取12例肝癌患者影像数据,统一给予靶区剂量50 Gy/5 F,在相同条件下分别对每例患者选择Fixed与Iris准直器进行治疗计划设计,通过靶区适形度指数(CI)、...目的:探讨及评价不同准直器(Fixed/Iris)的选择对治疗计划剂量学特点的影响。方法:选取12例肝癌患者影像数据,统一给予靶区剂量50 Gy/5 F,在相同条件下分别对每例患者选择Fixed与Iris准直器进行治疗计划设计,通过靶区适形度指数(CI)、均匀性指数(HI)、梯度指数(GI)、正常肝脏平均受量以及治疗时间等参数,分析评估计划优化质量及实施效率。结果:Iris组计划执行的平均治疗时间明显优于Fix组[(48.33±1.92)min vs(51.50±1.88)min,t=4.23,P=0.001],而CI(0.79±0.07 vs 0.80±0.08,t=0.52,P=0.613)、HI(0.42±0.14 vs 0.41±0.14,t=0.35,P=0.733)、GI(3.66±0.61 vs 3.60±0.50,t=1.15,P=0.273)、处方剂量归一值[(76.92±6.55)%vs(77.00±6.34)%,t=0.18,P=0.857]以及正常肝脏平均受量[(5.15±1.25)Gy vs(5.16±1.27)Gy,t=0.63,P=0.542]则无统计学差异。结论:CyberKnife系统中使用Iris相对Fixed准直器而言,除治疗时间明显缩短外,没有显著的剂量学差异。而对于其他部位肿瘤患者的治疗计划有无差异,还需进一步探讨和研究。展开更多
AIM To compare therapeutic outcomes and adverseevents in initial solitary hepatocellular carcinoma（HCC） treated with radiofrequency ablation （RFA） andCyberKnife？.METHODS： Seventy three consecutive patients withi...AIM To compare therapeutic outcomes and adverseevents in initial solitary hepatocellular carcinoma（HCC） treated with radiofrequency ablation （RFA） andCyberKnife？.METHODS： Seventy three consecutive patients withinitial solitary HCC treated with RFA （38 patients;RFA group） and CyberKnife （35 patients; CK group）were enrolled in this study. Background factorswere compared between the two groups. Local andintrahepatic distant recurrence control, and cumulativesurvival rates were compared between the two groups.These were determined using the Kaplan-Meier method,and the significance of differences was analyzed by log-rank test. The presence of more grade 3 on CTCAE ver.4.0 early and late adverse events was investigated.RESULTS： In background factors, age was significantlyhigher （P = 0.005） and the tumor diameter wassignificantly larger （P = 0.001） in the CK group. The1-year local recurrence control rates were 97.4%and 97.1% in the RFA and CK groups, respectively （P= 0.71）; the 1-year intrahepatic distant recurrencecontrol rates were 85.6% and 86.1%, respectively （P= 0.91）; and the 1-year cumulative survival rates were100% and 95.2%, respectively （P = 0.075）, showingno significant difference in any rate between the twogroups. There were no late adverse event in the RFAgroup, but 11.4% in the CK group had late adverseevents. In the CK group, the Child-Pugh score at 12 moafter treatment was significantly higher than that in theRFA group （P = 0.003） and significantly higher than thescore before treatment （P = 0.034）.CONCLUSION： The occurrence of adverse events is aconcern, but CyberKnife treatment is likely to becomean important option for local treatment of early HCC.展开更多
This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welh&...This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welhöfer Scanditronix with different serial numbers. The correction factor,, was studied using a Varian iX linac and the Cyberknife system. The measurements in the Varian iX were performed in a 10 × 10 cm2 field, 10 cm depth in liquid water at 90 cm and 70 cm SSD and in a 5.4 × 5.4 cm2 field, 10 cm depth at 70 cm SSD to simulate the Cyberknife conditions. In the Cyberknife system, measurements were performed using ionization chambers and both film types at 70 cm SSD and 10 cm depth in its 6 cm diameter reference field. The results indicate that ?is independent of the dosimeters and the evaluation methods. Maximum differences of 0.22% - 0.55% (combined uncertainties of 1.22% - 1.98%, k = 1) are obtained on ?using Varian iX, whereas discrepancies of 2.08% - 2.09% (combined uncertainties of 1.87% - 2.13%, k = 1) are observed using the Cyberknife system. Given the agreement between detectors and the combined standard uncertainties, the data from Varian iX could be considered the most accurate and consequently a weighted average factor of 0.902 ± 0.006 could be used for the Cyberknife VSI system reference field. Within measurement uncertainties, the absorbed dose rate measured in the Cyberknife VSI system reference field was found to be independent of the dosimeters used. These results suggest that the absorbed dose measured at a point within a given field size should be the same, regardless the dosimeter used, if their dosimetric characteristics are well known. This highlighted the importance of performing dosimetry by controlling all parameters that could affect the dosimeter response. One can conclude that radiochromic film dosimetry can be considered as an appropriate alternative for measuring absorbed dose to water rate.展开更多
Objective: To evaluate the treatments’ outcomes in brain metastatic tumors after CyberKnife treatment according to magnetic resonance imaging (MRI) findings and improvement of symptoms. Methods: A retrospective analy...Objective: To evaluate the treatments’ outcomes in brain metastatic tumors after CyberKnife treatment according to magnetic resonance imaging (MRI) findings and improvement of symptoms. Methods: A retrospective analysis of CyberKnife treatment;63 cases of patients with brain metastases;the use of CyberKnife treatment;short-term outcome evaluation after treatment and the MRI findings and measured before treatment and underwent diffusion-weighted imaging MRI scan of apparent diffusion coefficient (ADC) values. Results: 3 months after CyberKnife treatment and effectiveness were 82.5% and 96.8% respectively;6 months and one year survival rates were 82.5% and 55.6% respectively;the median survival time was 16 months. MRI of 52 patients (67 lesions) ADC values after treatment increased to some extent than before treatment. There are 38 lesions volume to shrink or disappear, no enhancement or slight enhancement in the lesion, no edema zone;27 lesions does not change in volume, no edema (18 lesions significantly weakened the degree of enhancement;6 lesions showed no obvious change enhancement;3 lesions showed ring enhancement, internal cystic);2 lesions volume were larger, heterogeneous enhancement, peripheral edema. Conclusion: CyberKnife is an effective method for treating brain metastatic tumor. MRI can accurately evaluate tumor lesions after treatment.展开更多
目的分析比较Cyberknife实施立体定向放射治疗(Stereotactic Body Radiation Therapy,SBRT)技术治疗椎体转移瘤时在不同方向的剂量跌落趋势。方法利用Cyberknife治疗8例胸椎转移瘤患者,4例患者给予靶区剂量40 Gy/5次,另外4例患者给予靶...目的分析比较Cyberknife实施立体定向放射治疗(Stereotactic Body Radiation Therapy,SBRT)技术治疗椎体转移瘤时在不同方向的剂量跌落趋势。方法利用Cyberknife治疗8例胸椎转移瘤患者,4例患者给予靶区剂量40 Gy/5次,另外4例患者给予靶区剂量33 Gy/3次,用Multi Plan4.0.2治疗计划系统设计优化治疗计划,使其能够满足临床治疗要求。就绝对剂量跌落梯度、相对剂量跌落梯度以及单位距离剂量跌落梯度3个方面统计比较Cyberknife治疗计划中剂量在4个不同方向的跌落趋势。结果在脊髓方向:单位绝对剂量跌落速度为(0.26±0.087)mm/100 c Gy,相对剂量跌落为(0.78±0.416)mm/5%Dmax,单位距离跌落速度为(309.95±127.45)c Gy/mm,且40 Gy组优于33 Gy组。在非脊髓方向,绝对剂量跌落平均速度为(0.725±0.223)mm/100 c Gy,相对剂量跌落为(1.476±0.553)mm/5%Dmax,单位距离跌速度为(217.930±36.493)c Gy/mm,各个方向的跌落速度无统计学差异。结论 Cyberknife治疗椎体转移瘤时,脊髓方向跌落快,加之其独特的追踪系统,对脊髓有较好的保护;而且等剂量线在各方向跌落较均匀,可以在给予大剂量治疗时更好的保护正常组织器官。Cyberknife应用于椎体转移瘤的立体定向放疗安全、有效。展开更多
BACKGROUND Paragangliomas(PG)are rare neoplasms of neuroendocrine origin that tend to be highly vascularized,slow-growing,and usually sporadic.To date,common treatment options are surgical resection(SR),with or withou...BACKGROUND Paragangliomas(PG)are rare neoplasms of neuroendocrine origin that tend to be highly vascularized,slow-growing,and usually sporadic.To date,common treatment options are surgical resection(SR),with or without radiation therapy(RT),and a watch-and-wait approach.AIM To evaluate the local control and effectiveness of exclusive fractionated stereotactic RT(FSRT)treatment in unresectable PG(uPG).METHODS We retrospectively evaluated patients with uPG(medically inoperable or refused SR)treated with FSRT with a Cyberknife System(Accuray Incorporated,Sunnyvale,California).Toxicity and initial efficacy were evaluated.RESULTS From May 2009 to January 2023,6 patients with a median age of 68(range 20-84)were treated with FSRT.The median delivered dose was 21 Gy(range 20-30 Gy)at a median isodose line of 75.5%(range 70%-76%)in 4 fractions(range 3-5 fractions).The median volume was 13.6 mL(range 12.4-65.24 mL).The median cumulative biological effective dose and equivalent dose in 2-Gy fractions were 70 Gy and 37.10 Gy respectively.Site of origin involved were the timpa-nojugular glomus(4/6),temporal bone,and cervical spine.In 1 of the 6 patients,the follow-up was insufficient;5 of 6 patients showed a 5-year overall survival and 5-year progression-free survival of 100%.We observed negligible toxicities during and after RT.The majority of patients showed stable symptoms during follow-up.Only 1 patient developed spine metastases.CONCLUSION Our preliminary results on this small cohort of patients suggest that FSRT could be an effective and safe alternative to SR.展开更多
Background Cyberknife can greatly raise the fractional dose of stereotactic radiosurgery, thus improving its clinical efficacy. We retrospectively analyzed clinical outcomes of brain metastasis treated with Cyberknife...Background Cyberknife can greatly raise the fractional dose of stereotactic radiosurgery, thus improving its clinical efficacy. We retrospectively analyzed clinical outcomes of brain metastasis treated with Cyberknife. Methods We analyzed 40 cases of brain metastases treated with Cyberknife in the Tianjin Cancer Hospital from August 1, 2006 to August 1, 2007, for a total of 68 lesions with maximal diameter of 0.4-7.5 cm （average 1.88 cm）. Total hypofractional radiated dosage was 18-36 Gy （5-25 Gy/F, 1-5 F） by Cyberknife. We evaluated the remission rate of clinical symptoms, correlation factors to new foci, 3-month local control rates, and 3-month and 1-year survival rates. All patients were followed up for more than 14 months. Results After 1 week, clinical remission was 90.0% （36/40）. After 3 months, the local control rate and therapeutic effective rate were 77.9% （53/68） and 94.1% （64/68）, respectively, as observed by cranium augmentation CT or MRI. The three-month, six-month and 1-year survival rates were 97.5% （39/40）, 82.5% （33/40） and 67.5% （27/40）, respectively. Fourteen patients had neopathy outside the original lesion after 3 months. Neopathy was not correlated with age, whole-brain radiotherapy, number of original lesions, maximum diameter of the original lesion, therapeutic dose per fraction, therapeutic frequency or total therapeutic dose. Conclusions Cyberknife got perfect clinical outcomes by higher dosage per fraction. It is an appropriate and valid treatment shortcut for brain metastasis.展开更多
Objective This study aims to quantify the uncertainties of CyberKnife Synchrony fiducial tracking for liver stereotactic body radiation therapy(SBRT)cases,and evaluate the required planning target volume(PTV)margins.M...Objective This study aims to quantify the uncertainties of CyberKnife Synchrony fiducial tracking for liver stereotactic body radiation therapy(SBRT)cases,and evaluate the required planning target volume(PTV)margins.Methods A total of 11 liver tumor patients with a total of 57 fractions,who underwent SBRT with synchronous fiducial tracking,were enrolled for the present study.The correlation/prediction model error,geometric error,and beam targeting error were quantified to determine the patient-level and fraction-level individual composite treatment uncertainties.The composite uncertainties and multiple margin recipes were compared for scenarios with and without rotation correction during treatment.Results The correlation model error-related uncertainty was 4.3±1.8,1.4±0.5 and 1.8±0.7 mm in the superior-inferior(SI),left-right,and anterior-posterior directions,respectively.These were the primary contributors among all uncertainty sources.The geometric error significantly increased for treatments without rotation correction.The fraction-level composite uncertainties had a long tail distribution.Furthermore,the generally used 5-mm isotropic margin covered all uncertainties in the left-right and anterior-posterior directions,and only 75%of uncertainties in the SI direction.In order to cover 90%of uncertainties in the SI direction,an 8-mm margin would be needed.For scenarios without rotation correction,additional safety margins should be added,especially in the superior-inferior and anterior-posterior directions.Conclusion The present study revealed that the correlation model error contributes to most of the uncertainties in the results.Most patients/fractions can be covered by a 5-mm margin.Patients with large treatment uncertainties might need a patient-specific margin.展开更多
文摘目的:探讨及评价不同准直器(Fixed/Iris)的选择对治疗计划剂量学特点的影响。方法:选取12例肝癌患者影像数据,统一给予靶区剂量50 Gy/5 F,在相同条件下分别对每例患者选择Fixed与Iris准直器进行治疗计划设计,通过靶区适形度指数(CI)、均匀性指数(HI)、梯度指数(GI)、正常肝脏平均受量以及治疗时间等参数,分析评估计划优化质量及实施效率。结果:Iris组计划执行的平均治疗时间明显优于Fix组[(48.33±1.92)min vs(51.50±1.88)min,t=4.23,P=0.001],而CI(0.79±0.07 vs 0.80±0.08,t=0.52,P=0.613)、HI(0.42±0.14 vs 0.41±0.14,t=0.35,P=0.733)、GI(3.66±0.61 vs 3.60±0.50,t=1.15,P=0.273)、处方剂量归一值[(76.92±6.55)%vs(77.00±6.34)%,t=0.18,P=0.857]以及正常肝脏平均受量[(5.15±1.25)Gy vs(5.16±1.27)Gy,t=0.63,P=0.542]则无统计学差异。结论:CyberKnife系统中使用Iris相对Fixed准直器而言,除治疗时间明显缩短外,没有显著的剂量学差异。而对于其他部位肿瘤患者的治疗计划有无差异,还需进一步探讨和研究。
文摘AIM To compare therapeutic outcomes and adverseevents in initial solitary hepatocellular carcinoma（HCC） treated with radiofrequency ablation （RFA） andCyberKnife？.METHODS： Seventy three consecutive patients withinitial solitary HCC treated with RFA （38 patients;RFA group） and CyberKnife （35 patients; CK group）were enrolled in this study. Background factorswere compared between the two groups. Local andintrahepatic distant recurrence control, and cumulativesurvival rates were compared between the two groups.These were determined using the Kaplan-Meier method,and the significance of differences was analyzed by log-rank test. The presence of more grade 3 on CTCAE ver.4.0 early and late adverse events was investigated.RESULTS： In background factors, age was significantlyhigher （P = 0.005） and the tumor diameter wassignificantly larger （P = 0.001） in the CK group. The1-year local recurrence control rates were 97.4%and 97.1% in the RFA and CK groups, respectively （P= 0.71）; the 1-year intrahepatic distant recurrencecontrol rates were 85.6% and 86.1%, respectively （P= 0.91）; and the 1-year cumulative survival rates were100% and 95.2%, respectively （P = 0.075）, showingno significant difference in any rate between the twogroups. There were no late adverse event in the RFAgroup, but 11.4% in the CK group had late adverseevents. In the CK group, the Child-Pugh score at 12 moafter treatment was significantly higher than that in theRFA group （P = 0.003） and significantly higher than thescore before treatment （P = 0.034）.CONCLUSION： The occurrence of adverse events is aconcern, but CyberKnife treatment is likely to becomean important option for local treatment of early HCC.
文摘This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welhöfer Scanditronix with different serial numbers. The correction factor,, was studied using a Varian iX linac and the Cyberknife system. The measurements in the Varian iX were performed in a 10 × 10 cm2 field, 10 cm depth in liquid water at 90 cm and 70 cm SSD and in a 5.4 × 5.4 cm2 field, 10 cm depth at 70 cm SSD to simulate the Cyberknife conditions. In the Cyberknife system, measurements were performed using ionization chambers and both film types at 70 cm SSD and 10 cm depth in its 6 cm diameter reference field. The results indicate that ?is independent of the dosimeters and the evaluation methods. Maximum differences of 0.22% - 0.55% (combined uncertainties of 1.22% - 1.98%, k = 1) are obtained on ?using Varian iX, whereas discrepancies of 2.08% - 2.09% (combined uncertainties of 1.87% - 2.13%, k = 1) are observed using the Cyberknife system. Given the agreement between detectors and the combined standard uncertainties, the data from Varian iX could be considered the most accurate and consequently a weighted average factor of 0.902 ± 0.006 could be used for the Cyberknife VSI system reference field. Within measurement uncertainties, the absorbed dose rate measured in the Cyberknife VSI system reference field was found to be independent of the dosimeters used. These results suggest that the absorbed dose measured at a point within a given field size should be the same, regardless the dosimeter used, if their dosimetric characteristics are well known. This highlighted the importance of performing dosimetry by controlling all parameters that could affect the dosimeter response. One can conclude that radiochromic film dosimetry can be considered as an appropriate alternative for measuring absorbed dose to water rate.
文摘Objective: To evaluate the treatments’ outcomes in brain metastatic tumors after CyberKnife treatment according to magnetic resonance imaging (MRI) findings and improvement of symptoms. Methods: A retrospective analysis of CyberKnife treatment;63 cases of patients with brain metastases;the use of CyberKnife treatment;short-term outcome evaluation after treatment and the MRI findings and measured before treatment and underwent diffusion-weighted imaging MRI scan of apparent diffusion coefficient (ADC) values. Results: 3 months after CyberKnife treatment and effectiveness were 82.5% and 96.8% respectively;6 months and one year survival rates were 82.5% and 55.6% respectively;the median survival time was 16 months. MRI of 52 patients (67 lesions) ADC values after treatment increased to some extent than before treatment. There are 38 lesions volume to shrink or disappear, no enhancement or slight enhancement in the lesion, no edema zone;27 lesions does not change in volume, no edema (18 lesions significantly weakened the degree of enhancement;6 lesions showed no obvious change enhancement;3 lesions showed ring enhancement, internal cystic);2 lesions volume were larger, heterogeneous enhancement, peripheral edema. Conclusion: CyberKnife is an effective method for treating brain metastatic tumor. MRI can accurately evaluate tumor lesions after treatment.
文摘BACKGROUND Paragangliomas(PG)are rare neoplasms of neuroendocrine origin that tend to be highly vascularized,slow-growing,and usually sporadic.To date,common treatment options are surgical resection(SR),with or without radiation therapy(RT),and a watch-and-wait approach.AIM To evaluate the local control and effectiveness of exclusive fractionated stereotactic RT(FSRT)treatment in unresectable PG(uPG).METHODS We retrospectively evaluated patients with uPG(medically inoperable or refused SR)treated with FSRT with a Cyberknife System(Accuray Incorporated,Sunnyvale,California).Toxicity and initial efficacy were evaluated.RESULTS From May 2009 to January 2023,6 patients with a median age of 68(range 20-84)were treated with FSRT.The median delivered dose was 21 Gy(range 20-30 Gy)at a median isodose line of 75.5%(range 70%-76%)in 4 fractions(range 3-5 fractions).The median volume was 13.6 mL(range 12.4-65.24 mL).The median cumulative biological effective dose and equivalent dose in 2-Gy fractions were 70 Gy and 37.10 Gy respectively.Site of origin involved were the timpa-nojugular glomus(4/6),temporal bone,and cervical spine.In 1 of the 6 patients,the follow-up was insufficient;5 of 6 patients showed a 5-year overall survival and 5-year progression-free survival of 100%.We observed negligible toxicities during and after RT.The majority of patients showed stable symptoms during follow-up.Only 1 patient developed spine metastases.CONCLUSION Our preliminary results on this small cohort of patients suggest that FSRT could be an effective and safe alternative to SR.
文摘Background Cyberknife can greatly raise the fractional dose of stereotactic radiosurgery, thus improving its clinical efficacy. We retrospectively analyzed clinical outcomes of brain metastasis treated with Cyberknife. Methods We analyzed 40 cases of brain metastases treated with Cyberknife in the Tianjin Cancer Hospital from August 1, 2006 to August 1, 2007, for a total of 68 lesions with maximal diameter of 0.4-7.5 cm （average 1.88 cm）. Total hypofractional radiated dosage was 18-36 Gy （5-25 Gy/F, 1-5 F） by Cyberknife. We evaluated the remission rate of clinical symptoms, correlation factors to new foci, 3-month local control rates, and 3-month and 1-year survival rates. All patients were followed up for more than 14 months. Results After 1 week, clinical remission was 90.0% （36/40）. After 3 months, the local control rate and therapeutic effective rate were 77.9% （53/68） and 94.1% （64/68）, respectively, as observed by cranium augmentation CT or MRI. The three-month, six-month and 1-year survival rates were 97.5% （39/40）, 82.5% （33/40） and 67.5% （27/40）, respectively. Fourteen patients had neopathy outside the original lesion after 3 months. Neopathy was not correlated with age, whole-brain radiotherapy, number of original lesions, maximum diameter of the original lesion, therapeutic dose per fraction, therapeutic frequency or total therapeutic dose. Conclusions Cyberknife got perfect clinical outcomes by higher dosage per fraction. It is an appropriate and valid treatment shortcut for brain metastasis.
基金This project was supported by the National Key R&D Program of China(No.2016YFC105300).
文摘Objective This study aims to quantify the uncertainties of CyberKnife Synchrony fiducial tracking for liver stereotactic body radiation therapy(SBRT)cases,and evaluate the required planning target volume(PTV)margins.Methods A total of 11 liver tumor patients with a total of 57 fractions,who underwent SBRT with synchronous fiducial tracking,were enrolled for the present study.The correlation/prediction model error,geometric error,and beam targeting error were quantified to determine the patient-level and fraction-level individual composite treatment uncertainties.The composite uncertainties and multiple margin recipes were compared for scenarios with and without rotation correction during treatment.Results The correlation model error-related uncertainty was 4.3±1.8,1.4±0.5 and 1.8±0.7 mm in the superior-inferior(SI),left-right,and anterior-posterior directions,respectively.These were the primary contributors among all uncertainty sources.The geometric error significantly increased for treatments without rotation correction.The fraction-level composite uncertainties had a long tail distribution.Furthermore,the generally used 5-mm isotropic margin covered all uncertainties in the left-right and anterior-posterior directions,and only 75%of uncertainties in the SI direction.In order to cover 90%of uncertainties in the SI direction,an 8-mm margin would be needed.For scenarios without rotation correction,additional safety margins should be added,especially in the superior-inferior and anterior-posterior directions.Conclusion The present study revealed that the correlation model error contributes to most of the uncertainties in the results.Most patients/fractions can be covered by a 5-mm margin.Patients with large treatment uncertainties might need a patient-specific margin.
