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
AIM:To evaluate impact of radiation therapy dose escalation through intensity modulated radiation therapy with simultaneous integrated boost(IMRT-SIB).METHODS:We retrospectively reviewed the patients who underwent fou...AIM:To evaluate impact of radiation therapy dose escalation through intensity modulated radiation therapy with simultaneous integrated boost(IMRT-SIB).METHODS:We retrospectively reviewed the patients who underwent four-dimensional-based IMRT-SIBbased neoadjuvant chemoradiation protocol.During the concurrent chemoradiation therapy,radiation therapy was through IMRT-SIB delivered in 28 consecutive daily fractions with total radiation doses of 56 Gy to tumor and 5040 Gy dose-painted to clinical tumor volume,with a regimen at the discretion of the treating medical oncologist.This was followed by surgical tumor resection.We analyzed pathological completion response(p CR) rates its relationship with overall survival and event-freesurvival.RESULTS:Seventeen patients underwent dose escalation with the IMRT-SIB protocol between 2007 and 2014 and their records were available for analysis.Among the IMRT-SIB-treated patients,the toxicity appeared mild,the most common side effects were grade 1-3 esophagitis(46%) and pneumonitis(11.7%).There were no cardiac events.The Ro resection rate was 94%(n = 16),the p CR rate was 47%(n = 8),and the postoperative morbidity was zero.There was one mediastinal failure found,one patient had local failure at the anastomosis site,and the majority of failures were distant in the lung or bone.The 3-year diseasefree survival and overall survival rates were 41%(n = 7) and 53%(n = 9),respectively.CONCLUSION:The dose escalation through IMRT-SIB in the chemoradiation regimen seems responsible for down-staging the distal esophageal with well-tolerated complications.展开更多
Aim: The simultaneous irradiation of target volumes of different total dose levels using intensity modulated radiotherapy leads to reduced doses per fraction and longer treatment times in target volumes of 2nd?to 4th?...Aim: The simultaneous irradiation of target volumes of different total dose levels using intensity modulated radiotherapy leads to reduced doses per fraction and longer treatment times in target volumes of 2nd?to 4th?order. Does the thereby caused reduced biological effectiveness induce an increased recurrence risk? The current work deals with the problem of recurrences of patients with head and neck carcinomas treated either with an intensitiy (IMRT) or with a volumetric modulated (VMAT) irradiation technique. Methods: From October 2002 to September 2014, 699 patients with carcinomas of the head and neck were irradiated using IMRT or VMAT. The median follow up of the patients was 21.9 months (2 to 145 months). Primary tumor regions (1st?order target volume) of 565 patients were treated with doses per fraction of 2 Gy. Accordingly, further 133 target volumes of the primary tumor received reduced doses per fraction. In 1 patient, the lymphatic drainage was treated solely without irradiation of the primary region. For the lympatic drainage, 854 1st?order target volumes were treated with a dose per fraction of 2 Gy. Reduced doses per fraction were applied to further 1780 target volumes. Results: 54 of 699 patients developed a recurrence in the primary tumor region after radio-(chemo) therapy, 4 patients developed a recurrence of the primary tumor and a unilateral recurrence of the lymphatic drainage, 2 patients a recurrence of the primary tumor and a bilateral lymph node recurrence. 18 patients showed an isolated unilateral recurrence and additionally 2 patients a bilateral recurrence of the lymphatic drainage. 619 patients stayed recurrence free. In primary tumor regions, receiving a dose per fraction of 2 Gy 55 patients (9.7%) developed a recurrence, whereas in target volumes receiving a reduced dose per fraction 5 patients (3.8%) developed a recurrence (p < 0.001). In lympatic drainage target volumes receiving a dose per fraction of 2 Gy, 25 target volumes (2.9%) developed a recurrence, whereas in target volumes receiving a reduced dose per fraction, 5 patients (0.3%) developed a recurrence (p = 0.001). Conclusion: The recurrence risk in target volumes of 2nd?to 4th?order was not increased due to reduced doses per fraction deposited by means of a simultaneous integrated boost technique. Therefore, the simultaneous irradiation of target volumes with different dose levels is safely applicable within one treatment plan.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.
文摘AIM:To evaluate impact of radiation therapy dose escalation through intensity modulated radiation therapy with simultaneous integrated boost(IMRT-SIB).METHODS:We retrospectively reviewed the patients who underwent four-dimensional-based IMRT-SIBbased neoadjuvant chemoradiation protocol.During the concurrent chemoradiation therapy,radiation therapy was through IMRT-SIB delivered in 28 consecutive daily fractions with total radiation doses of 56 Gy to tumor and 5040 Gy dose-painted to clinical tumor volume,with a regimen at the discretion of the treating medical oncologist.This was followed by surgical tumor resection.We analyzed pathological completion response(p CR) rates its relationship with overall survival and event-freesurvival.RESULTS:Seventeen patients underwent dose escalation with the IMRT-SIB protocol between 2007 and 2014 and their records were available for analysis.Among the IMRT-SIB-treated patients,the toxicity appeared mild,the most common side effects were grade 1-3 esophagitis(46%) and pneumonitis(11.7%).There were no cardiac events.The Ro resection rate was 94%(n = 16),the p CR rate was 47%(n = 8),and the postoperative morbidity was zero.There was one mediastinal failure found,one patient had local failure at the anastomosis site,and the majority of failures were distant in the lung or bone.The 3-year diseasefree survival and overall survival rates were 41%(n = 7) and 53%(n = 9),respectively.CONCLUSION:The dose escalation through IMRT-SIB in the chemoradiation regimen seems responsible for down-staging the distal esophageal with well-tolerated complications.
文摘Aim: The simultaneous irradiation of target volumes of different total dose levels using intensity modulated radiotherapy leads to reduced doses per fraction and longer treatment times in target volumes of 2nd?to 4th?order. Does the thereby caused reduced biological effectiveness induce an increased recurrence risk? The current work deals with the problem of recurrences of patients with head and neck carcinomas treated either with an intensitiy (IMRT) or with a volumetric modulated (VMAT) irradiation technique. Methods: From October 2002 to September 2014, 699 patients with carcinomas of the head and neck were irradiated using IMRT or VMAT. The median follow up of the patients was 21.9 months (2 to 145 months). Primary tumor regions (1st?order target volume) of 565 patients were treated with doses per fraction of 2 Gy. Accordingly, further 133 target volumes of the primary tumor received reduced doses per fraction. In 1 patient, the lymphatic drainage was treated solely without irradiation of the primary region. For the lympatic drainage, 854 1st?order target volumes were treated with a dose per fraction of 2 Gy. Reduced doses per fraction were applied to further 1780 target volumes. Results: 54 of 699 patients developed a recurrence in the primary tumor region after radio-(chemo) therapy, 4 patients developed a recurrence of the primary tumor and a unilateral recurrence of the lymphatic drainage, 2 patients a recurrence of the primary tumor and a bilateral lymph node recurrence. 18 patients showed an isolated unilateral recurrence and additionally 2 patients a bilateral recurrence of the lymphatic drainage. 619 patients stayed recurrence free. In primary tumor regions, receiving a dose per fraction of 2 Gy 55 patients (9.7%) developed a recurrence, whereas in target volumes receiving a reduced dose per fraction 5 patients (3.8%) developed a recurrence (p < 0.001). In lympatic drainage target volumes receiving a dose per fraction of 2 Gy, 25 target volumes (2.9%) developed a recurrence, whereas in target volumes receiving a reduced dose per fraction, 5 patients (0.3%) developed a recurrence (p = 0.001). Conclusion: The recurrence risk in target volumes of 2nd?to 4th?order was not increased due to reduced doses per fraction deposited by means of a simultaneous integrated boost technique. Therefore, the simultaneous irradiation of target volumes with different dose levels is safely applicable within one treatment plan.
