TY  - JOUR
AB  - Objective: To analyze and compare the radiation dose and image quality of kilo-voltage cone beam CT systems on different Varian accelerator platforms, providing data to support clinical decisions on selecting optimal protocols for image-guided radiotherapy based on cost-effective ratio (image quality / radiation dose). Methods: The radiation dose and image quality of various CBCT systems and scanning protocols on Varian Edge, Truebeam and ix (new and old) LINACs were obtained using a CT dose index (CTDI) phantom combined with a CT ionization chamber and a Catphan604 phantom, respectively. Figure of merit (FOM) was used to evaluate the cost-effective ratio of the image guidance schemes. Results: Considerable inter-system varieties of FOMs were observed, varying from 0.65 (Image Gently-full trajectory) to 48.46 (Image Gently-half trajectory). The inter-protocol varieties were also large, where the mean±SD was 22.14±13.47. Conclusions: Considering the explicit inter-system and inter-protocol varieties, it is clinically favorable to evaluate the image guidance schemes based on machine-specific measurement. For instance, parameters and equipment with low CTDIw can be beneficial for dose-sensitive patients. High CNR regimen favors patients with high image quality requirements. For ordinary patients, cost-effective ratio in terms of FOM can be very helpful to guide the decision-making of clinical image-guided radiotherapy.
AU  - Li, Y.*
AU  - Wu, H.*
AU  - Yang, J.*
AU  - Li, T.*
AU  - Yu, S.*
AU  - Lu, Z.*
AU  - Wang, M.*
AU  - Li, C.*
AU  - Li, W.B.
AU  - Zhang, Y.*
C1  - 60153
C2  - 49001
SP  - 595-599
TI  - Evaluation of cost-effective ratio (imaging quality vs. radiation dose) of Varian cone beam CT based on figure of merit (FOM).
JO  - Chin. J. Rad. Med. Prot.
VL  - 40
IS  - 8
PY  - 2020
SN  - 0254-5098
ER  - 

TY  - JOUR
AB  - Objective: To explore the feasibility and 
      optimization effect of modifying the Henry Ford Hospital (HFHS) 
      RapidPlan model for stereotactic body radiation therapy planning based 
      on local requirements. Methods: The following changes were made based on
       Henry Ford Health System(HFHS) Rapid Plan Lung SBRT model, taking the 
      latest clinical guideline evidence and local clinical practice into 
      account: Internal gross target volume(IGTV) and organ at risk(OAR) 
      structure, lung, were added and set corresponding parameters.The upper 
      value of planning target volume (PTV) was adjusted from 109% to 125%. 
      The original training library was replaced with 73 local historical 
      simultaneous integrated boosting plans, and statistical verification and
       outlier cleaning of the initial trained model were performed using 
      Model Analytics software. Totally 10 cases not included in the model 
      library were selected for independent verification, and automatic 
      optimization result of the models before and after modifying were 
      compared under the same beam condition. The following dosimetric 
      parameters were compared after target dose normalization: conformal 
      index (CI) of target volume, the mean doses, maximum doses and 
      dose-volume parameters of OARs. Results: The " tail" of the PTV's DVH 
      and the " shoulder" and " tail" of the IGTV's DVH of model M(local) 
      validation plan (M(local)_P) performs higher than the original model 
      HFHS (HFHS_P). The PTV_CI (1.07±0.13) of Mlocal_P were significantly 
      smaller than HFHS_P (1.25±0.24) (Z=-2.497, P<0.05). Except for 
      Heart_D15 cm3 and Heart_Dmax, most of the Mlocal_P dosimetric parameters
       of OARs were lower than HFHS_P, and the standard deviation was smaller.
       However, the difference of between two plans was no more than 3.06%. 10
       HFHS_P plans don't satisfy dose parameters requirement, two of which 
      PTV_CI values are 1.52 and 1.74, far beyond the clinically acceptable 
      range. Conclusions: Commercial model HFHS could be localized by 
      replacing training library and adjusting parameters. Moreover, plans 
      optimized by the modified model are local clinical acceptable in the 
      aspects of target volume conformity and hotspots, and have a better 
      performance in terms of OAR sparing and plan consistency.
AU  - Wang, H.*
AU  - Wu, H.*
AU  - Xiang, X.*
AU  - Huang, Y.*
AU  - Li, C.*
AU  - Hu, Q.*
AU  - Gong, J.*
AU  - Li, W.B.
AU  - Zhang, Y.B.*
C1  - 59017
C2  - 48468
SP  - 203-208
TI  - A feasibility study of local adaptation of HFHS Lung SBRT Rapid Plan commercial model.
JO  - Chin. J. Rad. Med. Prot.
VL  - 40
IS  - 3
PY  - 2020
SN  - 0254-5098
ER  -