Objective: To evaluate the clinical effects of concurrent and sequential therapy for middle and advanced stage non-small cell lung cancer (NSCLC) useing IMRT combined with NP regimen chemotherapy. Methods: Eighty pati...Objective: To evaluate the clinical effects of concurrent and sequential therapy for middle and advanced stage non-small cell lung cancer (NSCLC) useing IMRT combined with NP regimen chemotherapy. Methods: Eighty patients with middle and advanced stage NSCLC were randomized into two groups. Forty patients were underwent sequential therapy and other 40 patients were underwent concurrent therapy. IMRT was used in radiotherapy and NP regimen of vinorelbine+cispatin (NP) was used in chemotherapy. Results: (1) The overall response (CR+PR) rate was 75% in concurrent group and 45% in sequential group (P<0.05); (2) The treatment courses were 84 days and 140 days for concurrent group and sequential group respectively (P<0.05); (3) One-year survival rate in concurrent group was 72.4% and 52.3% in sequential group respectively; (4) The toxic effects can be tolerable by all of patients. Conclusion: The concurrent chemo-radiotherapy has better overall re- sponse, one-year survival rate and shorter treatment course than the sequential chemo-radiotherapy, so it is a better method for the treatment of middle and advanced stage NSCLC, but the long term survival rate will be studied.展开更多
Purpose: We performed both, dosimetric and positional accuracy verification of dynamic tumor tracking (DTT) intensity modulated radiation therapy (IMRT), with the Vero4DRT system using a moving phantom (QUASAR respira...Purpose: We performed both, dosimetric and positional accuracy verification of dynamic tumor tracking (DTT) intensity modulated radiation therapy (IMRT), with the Vero4DRT system using a moving phantom (QUASAR respiratory motion platform;QUASAR phantom) and system log files. Methods: The QUASAR phantom was placed on a treatment couch. Measurement of the point dose and dose distribution was performed for conventional IMRT, with the QUASAR phantom static and moving;for DTT IMRT, this was performed with the phantom moving for pyramid shaped, prostate, paranasal sinus, and pancreas targets. The QUASAR phantom was driven by a sinusoidal signal in the superior-inferior direction. Furthermore, predicted positional errors induced by the Vero4DRT system and mechanical positional errors of the gimbal head, were calculated using the system log files. Results and Conclusion: For DTT IMRT, the dose at the evaluation point was within 3% compared with the verification plan, and the dose distribution in the passing rates of γ was 97.9%, with the criteria of 3% dose and 3 mm distance to agreement. The position error calculated from the log files was within 2 mm, suggesting the feasibility of employing DTT IMRT with high accuracy using the Vero4DRT system.展开更多
Objective The aim of the study was to propose a hypothesis that local definitive intensity-modulated radiation therapy(IMRT) should be recommended for initially diagnosed metastatic nasopharyngeal carcinoma(NPC) and d...Objective The aim of the study was to propose a hypothesis that local definitive intensity-modulated radiation therapy(IMRT) should be recommended for initially diagnosed metastatic nasopharyngeal carcinoma(NPC) and demonstrate its feasibility.Methods Recently published papers on local definitive radiotherapy for initially diagnosed metastatic NPC were reviewed to propose a hypothesis.Results Several studies revealed the survival benefits of adding local definitive radiotherapy to the systemic chemotherapy in patients initially diagnosed with metastatic NPC.Conclusion We suggested that local definitive IMRT should be recommended in patients initially diagnosed with NPC with distant metastasis after an effective systemic chemotherapy, which may possibly prolong their survival time and potentially treat the disease.展开更多
Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate...Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.展开更多
This work aimed at evaluating the effect of 6- and 10-MV photon energies on intensity-modulated radiation therapy (IMRT) treatment plan outcome in different selected diagnostic cases. For such purpose, 19 patients, wi...This work aimed at evaluating the effect of 6- and 10-MV photon energies on intensity-modulated radiation therapy (IMRT) treatment plan outcome in different selected diagnostic cases. For such purpose, 19 patients, with different types of non CNS solid tumers, were selected. Clinical step-and-shoot IMRT treatment plans were designed for delivery on a Siemens Oncor accelerator with 82 leafs;multi-leaf collimators (MLCs). To ensure that the similarity or difference among the plans is due to energy alone, the same optimization constraints were applied for both energy plans. All the parameters like beam angles, number of beams, were kept constant to achieve the same clinical objectives. The Comparative evaluation was based on dose-volumetric analysis of both energy IMRT plans. Both qualitative and quantitative methods were used. Several physical indices for Planning Target Volume (PTV), the relevant Organs at Risk (OARs) as mean dose (Dmean), maximum dose (Dmax), 95% dose (D95), integral dose, total number of segments, and the number of MU were applied. Homogeneity index and conformation number were two other evaluation parameters that were considered in this study. Collectively, the use of 6 MV photons was dosimetrically comparable with 10 MV photons in terms of target coverage, homogeneity, conformity, and OAR savings. While 10-MV plans showed a significant reduction in the number of MUs that varied between 4.2% and 16.6% (P-value = 0.0001) for the different cases compared to 6-MV. The percentage volumes of each patient receiving 2 Gy and 5 Gy were compared for the two energies. The general trend was that 6-MV plans had the highest percentage volume, (P-value = 0.0001, P-value = 0.006) respectively. 10-MV beams actually decreased the integral dose (from average 183.27 ± 152.38 Gy-Kg to 178.08 ± 147.71 Gy-Kg, P-value = 0.004) compared with 6-MV. In general, comparison of the above parameters showed statistically significant differences between 6-MV and 10-MV groups. Based on the present results, the 10-MV is the optimal energy for IMRT, regardless of the concerns about a potential risk of radiation-induced malignancies. It is recommended that the choice to treat at 10 MV be taken as a risk vs. benefit as the clinical significance remains to be determined on case by case basis.展开更多
目的研究全段食管癌调强放射治疗计划设计中7野对称式布野与8野对称式布野的靶区及危及器官剂量学特点,为全段食管癌放射治疗患者的计划设计提供一定的参考。方法选择15例全段食管癌放射治疗患者,其中男性8例,女性7例;年龄45~84岁,平均...目的研究全段食管癌调强放射治疗计划设计中7野对称式布野与8野对称式布野的靶区及危及器官剂量学特点,为全段食管癌放射治疗患者的计划设计提供一定的参考。方法选择15例全段食管癌放射治疗患者,其中男性8例,女性7例;年龄45~84岁,平均年龄62.5岁;病灶直径(2.8±1.3)cm;病灶长度(14.6±3.7)cm。采用Eclipse计划系统,全组处方剂量均为50 Gy,以95%靶区体积达到100%处方剂量为基准,剂量体积直方图(DVH)比较7野对称式布野与8野对称式布野计划设计方法的主要危及器官的受量。结果靶区均匀性指数(HI),7野对称式布野与8野对称式布野差异无统计学意义(0.55±0.01 vs 0.56±0.01。t=-2.092,P>0.05)。通过比较,全段食管癌调强放射治疗8野对称式布野肺部V_(20)、V_(5)低于7野对称式布野计划[(21.56±3.26)%vs(25.72±1.65)%、(59.60±6.02)%vs(60.48±6.40)%],其他器官差异无统计学意义。结论常规全段食管癌调强放射治疗计划中使用8野对称式布野计划设计方法可有效地减少肺部高剂量区体积,从而进一步减少放射性肺炎的发生率。展开更多
We developed the first non-commercial treatment planning system for volumetric modulated arc therapy(VMAT) in the United States. Because VMAT involves multi-parameter modulations, it is imperative to develop a compreh...We developed the first non-commercial treatment planning system for volumetric modulated arc therapy(VMAT) in the United States. Because VMAT involves multi-parameter modulations, it is imperative to develop a comprehensive, rigorous and yet, practical procedure for routine patient-specific quality assurance(QA). In this paper, we presented our own approach as being currently implemented in our institution.Our patient-specific QA procedure involves multi-levels: pre-treatment QA,on-treatment QA, and posttreatment QA. The pre-treatment QA focuses on dosimetry verification, which is done with the commercial Map CHECK in Map PHAN mounted on an isocentric mounting fixture(IMF). This method is also referred to the fixed-gantry technique,i.e., the beams always remain perpendicular to the detector plane. The on-treatment QA involves in vivo optically stimulated luminescent dosimetry(OSLD).Prior to the treatment, two nano Dot TM OSLD dosimeters are placed on the patient abdomen under 1 cm bolus at the isocenter location. The irradiated dosimeters are then read by a nano Dot TM reader and the average reading of the two is calculated. The post-treatment QA involves the analysis of the Dyna Log and DLog files. The Dyna Log is a treatment log file that contains the planned and actual leaf positions at a given gantry angle. The DLog is a treatment log file that contains the planned segmented treatment table(STT) and the corresponding segment boundary samples, i.e., the actual delivered MU and gantry angle increment at each control point.展开更多
基金Supported by a grant from Health Bureau of Lianyungang City’s Fund Program (No. 05051).
文摘Objective: To evaluate the clinical effects of concurrent and sequential therapy for middle and advanced stage non-small cell lung cancer (NSCLC) useing IMRT combined with NP regimen chemotherapy. Methods: Eighty patients with middle and advanced stage NSCLC were randomized into two groups. Forty patients were underwent sequential therapy and other 40 patients were underwent concurrent therapy. IMRT was used in radiotherapy and NP regimen of vinorelbine+cispatin (NP) was used in chemotherapy. Results: (1) The overall response (CR+PR) rate was 75% in concurrent group and 45% in sequential group (P<0.05); (2) The treatment courses were 84 days and 140 days for concurrent group and sequential group respectively (P<0.05); (3) One-year survival rate in concurrent group was 72.4% and 52.3% in sequential group respectively; (4) The toxic effects can be tolerable by all of patients. Conclusion: The concurrent chemo-radiotherapy has better overall re- sponse, one-year survival rate and shorter treatment course than the sequential chemo-radiotherapy, so it is a better method for the treatment of middle and advanced stage NSCLC, but the long term survival rate will be studied.
文摘Purpose: We performed both, dosimetric and positional accuracy verification of dynamic tumor tracking (DTT) intensity modulated radiation therapy (IMRT), with the Vero4DRT system using a moving phantom (QUASAR respiratory motion platform;QUASAR phantom) and system log files. Methods: The QUASAR phantom was placed on a treatment couch. Measurement of the point dose and dose distribution was performed for conventional IMRT, with the QUASAR phantom static and moving;for DTT IMRT, this was performed with the phantom moving for pyramid shaped, prostate, paranasal sinus, and pancreas targets. The QUASAR phantom was driven by a sinusoidal signal in the superior-inferior direction. Furthermore, predicted positional errors induced by the Vero4DRT system and mechanical positional errors of the gimbal head, were calculated using the system log files. Results and Conclusion: For DTT IMRT, the dose at the evaluation point was within 3% compared with the verification plan, and the dose distribution in the passing rates of γ was 97.9%, with the criteria of 3% dose and 3 mm distance to agreement. The position error calculated from the log files was within 2 mm, suggesting the feasibility of employing DTT IMRT with high accuracy using the Vero4DRT system.
基金Supported by grants from Beijing Xisike Clinical Oncology Research Foundation(No.Y-Q201801-059)CSCO-Merck Serono Oncology Research Fund(No.Y-MT2015-007)
文摘Objective The aim of the study was to propose a hypothesis that local definitive intensity-modulated radiation therapy(IMRT) should be recommended for initially diagnosed metastatic nasopharyngeal carcinoma(NPC) and demonstrate its feasibility.Methods Recently published papers on local definitive radiotherapy for initially diagnosed metastatic NPC were reviewed to propose a hypothesis.Results Several studies revealed the survival benefits of adding local definitive radiotherapy to the systemic chemotherapy in patients initially diagnosed with metastatic NPC.Conclusion We suggested that local definitive IMRT should be recommended in patients initially diagnosed with NPC with distant metastasis after an effective systemic chemotherapy, which may possibly prolong their survival time and potentially treat the disease.
文摘Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.
文摘This work aimed at evaluating the effect of 6- and 10-MV photon energies on intensity-modulated radiation therapy (IMRT) treatment plan outcome in different selected diagnostic cases. For such purpose, 19 patients, with different types of non CNS solid tumers, were selected. Clinical step-and-shoot IMRT treatment plans were designed for delivery on a Siemens Oncor accelerator with 82 leafs;multi-leaf collimators (MLCs). To ensure that the similarity or difference among the plans is due to energy alone, the same optimization constraints were applied for both energy plans. All the parameters like beam angles, number of beams, were kept constant to achieve the same clinical objectives. The Comparative evaluation was based on dose-volumetric analysis of both energy IMRT plans. Both qualitative and quantitative methods were used. Several physical indices for Planning Target Volume (PTV), the relevant Organs at Risk (OARs) as mean dose (Dmean), maximum dose (Dmax), 95% dose (D95), integral dose, total number of segments, and the number of MU were applied. Homogeneity index and conformation number were two other evaluation parameters that were considered in this study. Collectively, the use of 6 MV photons was dosimetrically comparable with 10 MV photons in terms of target coverage, homogeneity, conformity, and OAR savings. While 10-MV plans showed a significant reduction in the number of MUs that varied between 4.2% and 16.6% (P-value = 0.0001) for the different cases compared to 6-MV. The percentage volumes of each patient receiving 2 Gy and 5 Gy were compared for the two energies. The general trend was that 6-MV plans had the highest percentage volume, (P-value = 0.0001, P-value = 0.006) respectively. 10-MV beams actually decreased the integral dose (from average 183.27 ± 152.38 Gy-Kg to 178.08 ± 147.71 Gy-Kg, P-value = 0.004) compared with 6-MV. In general, comparison of the above parameters showed statistically significant differences between 6-MV and 10-MV groups. Based on the present results, the 10-MV is the optimal energy for IMRT, regardless of the concerns about a potential risk of radiation-induced malignancies. It is recommended that the choice to treat at 10 MV be taken as a risk vs. benefit as the clinical significance remains to be determined on case by case basis.
文摘目的研究全段食管癌调强放射治疗计划设计中7野对称式布野与8野对称式布野的靶区及危及器官剂量学特点,为全段食管癌放射治疗患者的计划设计提供一定的参考。方法选择15例全段食管癌放射治疗患者,其中男性8例,女性7例;年龄45~84岁,平均年龄62.5岁;病灶直径(2.8±1.3)cm;病灶长度(14.6±3.7)cm。采用Eclipse计划系统,全组处方剂量均为50 Gy,以95%靶区体积达到100%处方剂量为基准,剂量体积直方图(DVH)比较7野对称式布野与8野对称式布野计划设计方法的主要危及器官的受量。结果靶区均匀性指数(HI),7野对称式布野与8野对称式布野差异无统计学意义(0.55±0.01 vs 0.56±0.01。t=-2.092,P>0.05)。通过比较,全段食管癌调强放射治疗8野对称式布野肺部V_(20)、V_(5)低于7野对称式布野计划[(21.56±3.26)%vs(25.72±1.65)%、(59.60±6.02)%vs(60.48±6.40)%],其他器官差异无统计学意义。结论常规全段食管癌调强放射治疗计划中使用8野对称式布野计划设计方法可有效地减少肺部高剂量区体积,从而进一步减少放射性肺炎的发生率。
文摘We developed the first non-commercial treatment planning system for volumetric modulated arc therapy(VMAT) in the United States. Because VMAT involves multi-parameter modulations, it is imperative to develop a comprehensive, rigorous and yet, practical procedure for routine patient-specific quality assurance(QA). In this paper, we presented our own approach as being currently implemented in our institution.Our patient-specific QA procedure involves multi-levels: pre-treatment QA,on-treatment QA, and posttreatment QA. The pre-treatment QA focuses on dosimetry verification, which is done with the commercial Map CHECK in Map PHAN mounted on an isocentric mounting fixture(IMF). This method is also referred to the fixed-gantry technique,i.e., the beams always remain perpendicular to the detector plane. The on-treatment QA involves in vivo optically stimulated luminescent dosimetry(OSLD).Prior to the treatment, two nano Dot TM OSLD dosimeters are placed on the patient abdomen under 1 cm bolus at the isocenter location. The irradiated dosimeters are then read by a nano Dot TM reader and the average reading of the two is calculated. The post-treatment QA involves the analysis of the Dyna Log and DLog files. The Dyna Log is a treatment log file that contains the planned and actual leaf positions at a given gantry angle. The DLog is a treatment log file that contains the planned segmented treatment table(STT) and the corresponding segment boundary samples, i.e., the actual delivered MU and gantry angle increment at each control point.
