Objective： The aim of the work was to compare the dosimetric results that were obtained by using two treatment planning systems （TPS） Siemens KonRad version 2.2.23, Elekta XiO version 4.4 to perform a simultaneous ...Objective： The aim of the work was to compare the dosimetric results that were obtained by using two treatment planning systems （TPS） Siemens KonRad version 2.2.23, Elekta XiO version 4.4 to perform a simultaneous integrated boost （SIB） for head and neck and central nervous system （CNS） cases in paediatric patients. Methods： The CT scan data for five paediatric patients, with head and neck and CNS tumors, were transferred into both of the TPSs. Clinical step-and-shoot intensity-modulated radiotherapy （IMRT） treatment plans were designed using 6 MV photon beam for delivery on a Siemens Oncor Accelerator with multileaf collimator MLC （82 leaf）. Plans were optimized to achieve the same clinical objectives using the same beam energy, number and direction of beams. The analysis was based on isodose distributions, the dose volume histogram （DVH） for planning target volume （PTV） and the relevant organs at risk （OARs） as well as volume receiving 2 Gy and 5 Gy, also total number of segments, MU/segment, and the number of MU/cGy had been investigated. Treatment delivery time and conformation number were two other parameters in this study. Results： The segmentation using KonRad was more efficient, resulting in fewer segments （reduction between 13.2% and 48.3%）, fewer M Us （reduction between 10.7% and 33%） and that reflected on treatment delivery times to be shorter by up to 8 rain or 46%. In most of the cases KonRad had the highest volume receiving in excess of 2 and 5 Gy, and XiO showed the lowest. Also KonRad achieved slightly better conformality （0.76 ± 0.054） than XiO （0.73 ± 0.05） while XiO presented a higher modulation factor value （3.3 MU/cGy） than KonRad （2.4 MU/cGy）. Conclusion： The KonRad treatment planning system was found to be superior to the XiO treatment planning system. This is true for the possible increase of radiation-induced secondary malignancies as well as for the local control.展开更多
Objective:The aim of this study was to assess the long-term effect of breast conservation with breast intensitymodulated radiotherapy (IMRT) for early-stage breast cancers.Methods:Pub Med,EMBASE,Cochrane Library,Chine...Objective:The aim of this study was to assess the long-term effect of breast conservation with breast intensitymodulated radiotherapy (IMRT) for early-stage breast cancers.Methods:Pub Med,EMBASE,Cochrane Library,Chinese Biomedical Literature Database were searched to identify relevant original published trails,and the references of eligible studies were manually screened.Randomized controlled trails reported in any language,comparing breast IMRT with conventional radiotherapy (RT) in patients with early-stage breast cancer were eligible for inclusion.Two investigators independently assessed the quality of included trials and extracted data.The RevMan 5.0 software was used for statistical analysis.Results:Four trials involving 1440 patients were included.The results showed that in the IMRT group,the occurrence of acute moist dermatitis,the edema of the mammary gland and the occurrence of hyperpigmentation were lower than those of RT group,the pooled risk ratio value and 95% confidence interval were 0.28 (0.17-0.48),0.03 (0.00-0.21) and 0.06 (0.02-0.15) respectively.The use of IMRT did not correlate with pain and quality of life,but the presence of moist desquamation did significantly correlate with pain and reduced quality of life.Conclusion:The currently available evidence showed that IMRT significantly reduces the occurrence of moist acute dermatitis anywhere in the breast and alleviates the suffering of patients and improves the quality of life of patients.Future large-scale,high-quality,double-blind trials are needed.展开更多
Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional thr...Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional three-dimensional conformal radiotherapy （3DCRT） in the radiotherapy of rectal cancer. Methods： Fifteen patients with rectal cancer treated with radio- therapy （RT） were retrospectively analyzed. Among the patients, seven received RT preoperatively and 8 postoperatively. The target volume and the OARs such as the small bowel, bladder and femoral heads were contoured for each patient. 3DCRT-plan and IMRT-plan were performed for each patient respectively, with the prescribed dose covering at least 95% of the planning target volume （PTV）. The conformity index （CI） and homogeneity index （HI） were used for evaluation of the dose distribution in the target volume, and the Dx% （the lowest dose to the x% volume of the OARs that received the highest dose of irradiation） and the mean dose were used for evaluation of the dose to OARs. Paired-T test was used for companson of the difference between the two plans. Results： In the IMRT-plan and 3DCRT-plan, the CI were 0.94 and 0.87 （P = 0.000） and the HI were 1.13 and 1.17, respectively （P = 0.001）. For small bowel, the D30%, D50% and the mean dose were 19.67 Gy, 15.13 Gy and 18.81 Gy in the IMRT-plan and 25.20 Gy, 22.20 Gy and 22.89 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For bladder, the D30%, D50%, and the mean dose were 24.80 Gy, 34.20 Gy and 28.70 Gy in the IMRT- plan, and 35.07 Gy, 44.67 Gy and 35.68 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For femoral heads, the D5% in the IMRT-plan and 3DCRT-plan were 40.6 Gy and 40.47 Gy, respectively （P = 0.936）, and the mean dose were 30.14 Gy and 25.57 Gy, respectively （P = 0.001）. Conclusion： Five-field IMRT-plan is better than 3DCRT-plan in the conformity and the dose homogeneity within target volume and also better in sparing the small bowel and bladder.展开更多
Objective The aim of the study was to compare tomotherapy-based bone marrow-sparing intensity-mod- ulated radiotherapy （BMS-IMRT） with intensity-modulated radiotherapy （IMRT） without entering the pelvic bone marro...Objective The aim of the study was to compare tomotherapy-based bone marrow-sparing intensity-mod- ulated radiotherapy （BMS-IMRT） with intensity-modulated radiotherapy （IMRT） without entering the pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IMRT and IMRT plans were designed for a cohort of nine patients. The prescribed dose was 45 Gy in 1.8 Gy daily fractions, and 95% of the planned target volume received this dose. The doses were computed using a commercially available treatment planning system with the convolution/superposition algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices （HI and CI） as well as organ at risk dose and volume parameters. Results BMS-IMRT had advantages over IMRT in terms of CI, but was equivalent to the latter in H1. V5, V10, V20, V30, and V40 of pelvic bone marrow in BMS-IMRT decreased by 0.06%, 17.33%, 22.19%, 13.85%, and 16.46%, respectively, compared with IMRT. Except for V30 of the small bowel and V30 and V40 of the bladder, no statistically significant differences were found between BMS-IMRT and IMRT in the small bowel, bladder, and rectum. Conclusion For cervical cancer patients receiving tomotherapy-based radiotherapy after hysterectomy, BMS-IMRT reduced pelvic bone marrow volume receiving low-dose radiation, and it may be conducive to preventing acute hematologic toxicity.展开更多
Objective The aim of this study was to investigate tumor volume changes with kilovoltage cone-beam computed tomography （kV-CBCT） and their dosimetric consequences for non-operative lung cancer during intensity-modul...Objective The aim of this study was to investigate tumor volume changes with kilovoltage cone-beam computed tomography （kV-CBCT） and their dosimetric consequences for non-operative lung cancer during intensity-modulated radiotherapy （IMRT） or fractionated stereotactic radiotherapy. Methods Eighteen patients with non-operative lung cancer who received IMRT consisting of 1.8-2.2 Gy/fraction and five fractions per week or stereotactic radiotherapy with 5-8 Gy/fraction and three fractions a week were studied, kV-CBCT was performed once per week during IMRT and at every fraction during stereotactic radiotherapy. The gross tumor volume （GTV） was contoured on the kV-CBCT images, and adaptive treatment plans were created using merged kV-CBCT and primary planning computed tomogra- phy image sets. Tumor volume changes and dosimetric parameters, including the minimum dose to 95% （D95） or 1% （D1） of the planning target volume （PTV）, mean lung dose （MLD）, and volume of lung tissue that received more than 5 （Vs）, 10 （Vl0）, 20 （V20）, and 30 （V30） Gy were retrospectively analyzed. Results The average maximum change in GTV observed during IMRT or fractionated stereotactic radio- therapy was -25.85% （range, -13.09% --56.76%）. The D95 and Dr of PTV for the adaptive treatment plans in all patients were not significantly different from those for the initial or former adaptive treatment plans. In patients with tumor volume changes of 〉20% in the third or fourth week of treatment during IMRT, adap- tive treatment plans offered clinically meaningful decreases in MLD and V5, V10, V20, and V30; however, in patients with tumor volume changes of 〈 20% in the third or fourth week of treatment as well as in patients with stereotactic radiotherapy, there were no significant or clinically meaningful decreases in the dosimetric parameters. Conclusion Adaptive treatment planning for decreasing tumor volume during IMRT may be beneficial for patients who experience tumor volume changes of 〉20% in the third or fourth week of treatment.展开更多
Objective: The study is a comparative study, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating nasopharyngeal carcinomas; dosimetricall...Objective: The study is a comparative study, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating nasopharyngeal carcinomas; dosimetrically evaluating and comparing both techniques as regard target coverage and doses to organs at risk (OAR). Methods: Twenty patients with nasopharyngeal carcinoma were treated by 3D-CRT technique and another 20 patients were treated by IMRT. A dosimetric comparison was done by performing two plans for the same patient using Eclipse planning system (version 8.6). Results: IMRT had a better tumor coverage and conformity index compared to 3D-CRT plans (P value of 0.001 and 0.004), respectively. As for the dose homogeneity it was also better in the IMRT plans and the reason for this was attributed to the dose inhomogeneity at the photon/electron junction in the 3D-CRT plans (P value 0.032). Also, doses received by the risk structures, particularly parotids, was significantly less in the IMRT plans than those of 3D-CRT (P value 0.001). Conclusion: IMRT technique was clearly able to increase the dose delivery to the target volume, improve conformity and homogeneity index and spare the parotid glands in comparison to 3D-CRT technique.展开更多
文摘Objective： The aim of the work was to compare the dosimetric results that were obtained by using two treatment planning systems （TPS） Siemens KonRad version 2.2.23, Elekta XiO version 4.4 to perform a simultaneous integrated boost （SIB） for head and neck and central nervous system （CNS） cases in paediatric patients. Methods： The CT scan data for five paediatric patients, with head and neck and CNS tumors, were transferred into both of the TPSs. Clinical step-and-shoot intensity-modulated radiotherapy （IMRT） treatment plans were designed using 6 MV photon beam for delivery on a Siemens Oncor Accelerator with multileaf collimator MLC （82 leaf）. Plans were optimized to achieve the same clinical objectives using the same beam energy, number and direction of beams. The analysis was based on isodose distributions, the dose volume histogram （DVH） for planning target volume （PTV） and the relevant organs at risk （OARs） as well as volume receiving 2 Gy and 5 Gy, also total number of segments, MU/segment, and the number of MU/cGy had been investigated. Treatment delivery time and conformation number were two other parameters in this study. Results： The segmentation using KonRad was more efficient, resulting in fewer segments （reduction between 13.2% and 48.3%）, fewer M Us （reduction between 10.7% and 33%） and that reflected on treatment delivery times to be shorter by up to 8 rain or 46%. In most of the cases KonRad had the highest volume receiving in excess of 2 and 5 Gy, and XiO showed the lowest. Also KonRad achieved slightly better conformality （0.76 ± 0.054） than XiO （0.73 ± 0.05） while XiO presented a higher modulation factor value （3.3 MU/cGy） than KonRad （2.4 MU/cGy）. Conclusion： The KonRad treatment planning system was found to be superior to the XiO treatment planning system. This is true for the possible increase of radiation-induced secondary malignancies as well as for the local control.
基金Supported by a grant from the National Nature Science Foundation of China(No. 096RJZA036)
文摘Objective:The aim of this study was to assess the long-term effect of breast conservation with breast intensitymodulated radiotherapy (IMRT) for early-stage breast cancers.Methods:Pub Med,EMBASE,Cochrane Library,Chinese Biomedical Literature Database were searched to identify relevant original published trails,and the references of eligible studies were manually screened.Randomized controlled trails reported in any language,comparing breast IMRT with conventional radiotherapy (RT) in patients with early-stage breast cancer were eligible for inclusion.Two investigators independently assessed the quality of included trials and extracted data.The RevMan 5.0 software was used for statistical analysis.Results:Four trials involving 1440 patients were included.The results showed that in the IMRT group,the occurrence of acute moist dermatitis,the edema of the mammary gland and the occurrence of hyperpigmentation were lower than those of RT group,the pooled risk ratio value and 95% confidence interval were 0.28 (0.17-0.48),0.03 (0.00-0.21) and 0.06 (0.02-0.15) respectively.The use of IMRT did not correlate with pain and quality of life,but the presence of moist desquamation did significantly correlate with pain and reduced quality of life.Conclusion:The currently available evidence showed that IMRT significantly reduces the occurrence of moist acute dermatitis anywhere in the breast and alleviates the suffering of patients and improves the quality of life of patients.Future large-scale,high-quality,double-blind trials are needed.
文摘Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional three-dimensional conformal radiotherapy （3DCRT） in the radiotherapy of rectal cancer. Methods： Fifteen patients with rectal cancer treated with radio- therapy （RT） were retrospectively analyzed. Among the patients, seven received RT preoperatively and 8 postoperatively. The target volume and the OARs such as the small bowel, bladder and femoral heads were contoured for each patient. 3DCRT-plan and IMRT-plan were performed for each patient respectively, with the prescribed dose covering at least 95% of the planning target volume （PTV）. The conformity index （CI） and homogeneity index （HI） were used for evaluation of the dose distribution in the target volume, and the Dx% （the lowest dose to the x% volume of the OARs that received the highest dose of irradiation） and the mean dose were used for evaluation of the dose to OARs. Paired-T test was used for companson of the difference between the two plans. Results： In the IMRT-plan and 3DCRT-plan, the CI were 0.94 and 0.87 （P = 0.000） and the HI were 1.13 and 1.17, respectively （P = 0.001）. For small bowel, the D30%, D50% and the mean dose were 19.67 Gy, 15.13 Gy and 18.81 Gy in the IMRT-plan and 25.20 Gy, 22.20 Gy and 22.89 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For bladder, the D30%, D50%, and the mean dose were 24.80 Gy, 34.20 Gy and 28.70 Gy in the IMRT- plan, and 35.07 Gy, 44.67 Gy and 35.68 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For femoral heads, the D5% in the IMRT-plan and 3DCRT-plan were 40.6 Gy and 40.47 Gy, respectively （P = 0.936）, and the mean dose were 30.14 Gy and 25.57 Gy, respectively （P = 0.001）. Conclusion： Five-field IMRT-plan is better than 3DCRT-plan in the conformity and the dose homogeneity within target volume and also better in sparing the small bowel and bladder.
基金Supported by a grant of the Military Medical Metrology Project(No.2011-JL2-005)
文摘Objective The aim of the study was to compare tomotherapy-based bone marrow-sparing intensity-mod- ulated radiotherapy （BMS-IMRT） with intensity-modulated radiotherapy （IMRT） without entering the pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IMRT and IMRT plans were designed for a cohort of nine patients. The prescribed dose was 45 Gy in 1.8 Gy daily fractions, and 95% of the planned target volume received this dose. The doses were computed using a commercially available treatment planning system with the convolution/superposition algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices （HI and CI） as well as organ at risk dose and volume parameters. Results BMS-IMRT had advantages over IMRT in terms of CI, but was equivalent to the latter in H1. V5, V10, V20, V30, and V40 of pelvic bone marrow in BMS-IMRT decreased by 0.06%, 17.33%, 22.19%, 13.85%, and 16.46%, respectively, compared with IMRT. Except for V30 of the small bowel and V30 and V40 of the bladder, no statistically significant differences were found between BMS-IMRT and IMRT in the small bowel, bladder, and rectum. Conclusion For cervical cancer patients receiving tomotherapy-based radiotherapy after hysterectomy, BMS-IMRT reduced pelvic bone marrow volume receiving low-dose radiation, and it may be conducive to preventing acute hematologic toxicity.
文摘Objective The aim of this study was to investigate tumor volume changes with kilovoltage cone-beam computed tomography （kV-CBCT） and their dosimetric consequences for non-operative lung cancer during intensity-modulated radiotherapy （IMRT） or fractionated stereotactic radiotherapy. Methods Eighteen patients with non-operative lung cancer who received IMRT consisting of 1.8-2.2 Gy/fraction and five fractions per week or stereotactic radiotherapy with 5-8 Gy/fraction and three fractions a week were studied, kV-CBCT was performed once per week during IMRT and at every fraction during stereotactic radiotherapy. The gross tumor volume （GTV） was contoured on the kV-CBCT images, and adaptive treatment plans were created using merged kV-CBCT and primary planning computed tomogra- phy image sets. Tumor volume changes and dosimetric parameters, including the minimum dose to 95% （D95） or 1% （D1） of the planning target volume （PTV）, mean lung dose （MLD）, and volume of lung tissue that received more than 5 （Vs）, 10 （Vl0）, 20 （V20）, and 30 （V30） Gy were retrospectively analyzed. Results The average maximum change in GTV observed during IMRT or fractionated stereotactic radio- therapy was -25.85% （range, -13.09% --56.76%）. The D95 and Dr of PTV for the adaptive treatment plans in all patients were not significantly different from those for the initial or former adaptive treatment plans. In patients with tumor volume changes of 〉20% in the third or fourth week of treatment during IMRT, adap- tive treatment plans offered clinically meaningful decreases in MLD and V5, V10, V20, and V30; however, in patients with tumor volume changes of 〈 20% in the third or fourth week of treatment as well as in patients with stereotactic radiotherapy, there were no significant or clinically meaningful decreases in the dosimetric parameters. Conclusion Adaptive treatment planning for decreasing tumor volume during IMRT may be beneficial for patients who experience tumor volume changes of 〉20% in the third or fourth week of treatment.
文摘Objective: The study is a comparative study, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating nasopharyngeal carcinomas; dosimetrically evaluating and comparing both techniques as regard target coverage and doses to organs at risk (OAR). Methods: Twenty patients with nasopharyngeal carcinoma were treated by 3D-CRT technique and another 20 patients were treated by IMRT. A dosimetric comparison was done by performing two plans for the same patient using Eclipse planning system (version 8.6). Results: IMRT had a better tumor coverage and conformity index compared to 3D-CRT plans (P value of 0.001 and 0.004), respectively. As for the dose homogeneity it was also better in the IMRT plans and the reason for this was attributed to the dose inhomogeneity at the photon/electron junction in the 3D-CRT plans (P value 0.032). Also, doses received by the risk structures, particularly parotids, was significantly less in the IMRT plans than those of 3D-CRT (P value 0.001). Conclusion: IMRT technique was clearly able to increase the dose delivery to the target volume, improve conformity and homogeneity index and spare the parotid glands in comparison to 3D-CRT technique.
