ABSTRACT
Objective To assess the feasibility of secondary check by LinaTech TiGRT treatment planning systems.Methods Choosing the Linatech TiGRT treatment planning system,researched and developed by Linatech company,as the third-party check tools.First,using Linatech TPS for recomputing treatment plans for geometrical phantoms designed in TG-119 and patients.after computation,compared the point dose with the measured data of phantoms (Using chameber No.2571 to measure point dose) and original plans.Using PTW verisoft with a criteria of 3% dose difference and 5 mm distance to agreement to assess the dose distribution on center level.After then,you can assess the accuracy of treatment plans.Results Tiny volume changes were found in ROI,especially in small size phantoms orcuspidal regions.For comparing measured data with recomputed plans and original plans,the dose data were found basically identical in TG-119 phantoms.And for patients,the differences between recomputed plans and AAA original plans or AXB original plans were smaller in breast cancer,but they were even bigger innasopharynx cancer,all patient cases showed a gamma passing rate more than 90%.The gamma passing rate of AAA original plans and AXB original plans were 95.6% and 97.53% for breast cancer,and 94.67% and 96.83% for nasopharynx cancer.Conclusions The method of utilizing the LinaTech TiGRT treatment planning system as a third-party check tools to assess the accuracy of plans is feasible,and the validation process is convenient,but some functions still need to improve and the scope of differences still need more patient cases to determine.
ABSTRACT
Objective To assess the outcomes of involved field irradiation (IFI) and elective nodal irradiation (ENI) in patients older than 70 years with esophageal squamous-cell carcinoma(SCC) receiving radical IMRT,and to determine whether IFI is feasible in these patients.Methods Totally 79 patients older than 70 years diagnosed with SCC of esophagus without distant metastases were collected.48 patients were received IFI,and the other 31 patients were treated with ENI.With a median follow-up time of 24 months,disease-free survival,overall survival,patterns of failure,irradiated lung dose and radiation pneumonitis were observed and compared between IFI and ENI groups.Results In IFI and ENI arm,the disease-free survival rates of 1,2,3 years were 60.4％,34.9％,29.7％ and 64.5％,54.0％,35.0％,respectively(P ＞0.05).The 1-,2-,and 3-year survival rates were 72.9％,43.4％,31.5％ for the IFI arm,and 73.0％,53.0％,38.3％ for the ENI arm(P ＞ 0.05).The ENI arm had a tendency to expand survival,but the two arms had no significant difference (P ＞ 0.05).The patterns of failure also had no difference between the two arms.Distant failure,local failure,uninvolved nodal failure in IFI arm were 22.9％,27.0％,4.2％,while in ENI arm were 25.8％,0,19.4％,all of them had no significant difference (P ＞ 0.05).However,the lung V5,V20,mean lung dose in ENI arm were higher than that in IFI and all of them had a significantly difference (t =4.66,29.90,15.63,P ＜ 0.05).The radiation pneumonitis rates were higher in ENI than in IFI arm.The rates of degree 1-2 and degree 3 were 22％,19％,and 13％ and 4％ in the two arms,respectively,with a significantly difference(x2 =4.55,4.77,P ＜ 0.05).Conclusions It is feasible that IFI for definitive IMRT in the elderly patients older than 70 years with SCC,because it got similar disease-free survival and overall survival but with less lung doses along with decreased radio-pulmonary lesion when compared with ENI.