scholarly journals Comprehensive comparison of Local Effect Model IV predictions with the Particle Irradiation Data Ensemble

2021 ◽  
Author(s):  
Tabea Pfuhl ◽  
Thomas Friedrich ◽  
Michael Scholz
Keyword(s):  
Local Effect ◽  
Particle Irradiation ◽  
Effect Model ◽  
Comprehensive Comparison

scholarly journals A local effect model-based interpolation framework for experimental nanoparticle radiosensitisation data

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Jeremy M. C. Brown ◽  
Fred J. Currell
Keyword(s):  
Local Effect ◽  
Model Based ◽  
Effect Model

scholarly journals RBE-weighted dose conversions for patients with recurrent nasopharyngeal carcinoma receiving carbon-ion radiotherapy from the local effect model to the microdosimetric kinetic model

2020 ◽  
Author(s):  
Liwen Zhang ◽  
Weiwei Wang ◽  
Jiyi Hu ◽  
Jiade Lu ◽  
Lin Kong
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Kinetic Model ◽  
Target Volume ◽  
Local Effect ◽  
Carbon Ion Radiotherapy ◽  
Carbon Ion ◽  
Effect Model ◽  
Target Volumes ◽  
Treatment Plans ◽  
Recurrent Nasopharyngeal Carcinoma

Abstract Background We sought to establish a conversion curve to convert the local effect model I (LEM) based RBE-weighted doses (LEM doses) in patients with locally recurrent nasopharyngeal carcinoma (rNPC) to the microdosimetric kinetic model (MKM) based RBE-weighted dose (MKM doses) model. We also converted the relevant organ at risk (OAR) constraints based on this curve. Methods Data from 13 patients with rNPC receiving carbon-ion radiotherapy (CIRT) in our hospital were collected. LEM in Raystation (V8A, Raystation, Sweden) was used to generate treatment plans. Clinical target volume CTV1(GTV+5mm)was given 63 Gy (RBE) in 21 fractions. Ninety-nine percent of target volumes should be covered by 95% of the prescriptions; the maximum doses of the brainstem and spinal cord were < 45 Gy (RBE) and < 30 Gy (RBE), respectively. The doses covering 20% volumes of optical nerves/chiasms D20 were < 30 Gy (RBE). Then physical doses of the LEM plans were recalculated by using MKM in Raystation to generate MKM plans. A series of the ratio of LEM dose to MKM dose was obtained as the conversion factor to obtain the conversion curve by using an isovolumetric dose method. Using prescriptions and OAR, constraints were converted to MKM doses with this curve. Results Conversion factors (LEM dose/MKM dose) from 1.37±0.02 to 3.09±0.09 corresponded to the LEM fractionated doses from 0.24 Gy (RBE) to 2.86 Gy (RBE), including the doses constraining upon OARs. LEM doses of 30 Gy (RBE) and 45 Gy (RBE) in 21 fractions were converted to MKM doses of 16.64 Gy (RBE) and 30.98 Gy (RBE) in 16 fractions. Conclusions This conversion curve could be used to convert LEM doses to MKM doses for patients with rNPC receiving CIRT, providing dose references for re-irradiation therapy.

scholarly journals RBE-weighted dose conversions for patients with recurrent nasopharyngeal carcinoma receiving carbon-ion radiotherapy from the local effect model to the microdosimetric kinetic model

2020 ◽  
Author(s):  
Liwen Zhang ◽  
Weiwei Wang ◽  
Jiyi Hu ◽  
Jiade Lu ◽  
Lin Kong
Keyword(s):  
Spinal Cord ◽  
Nasopharyngeal Carcinoma ◽  
Kinetic Model ◽  
Local Effect ◽  
Carbon Ion Radiotherapy ◽  
Conversion Factors ◽  
Carbon Ion ◽  
Effect Model ◽  
Recurrent Nasopharyngeal Carcinoma ◽  
Dose Constraints

Abstract Background: We sought to establish a conversion curve to convert the RBE-weighted doses calculated by local effect model I (LEM) (LEM RBE-weighted doses) in patients with locally recurrent nasopharyngeal carcinoma (rNPC) to the RBE-weighted doses calculated by microdosimetric kinetic model (MKM) (MKM RBE-weighted doses). We also converted the LEM dose constraints (RBE-weighted dose constraints in LEM plans) for the brain stem, spinal cord, and optic nerve based on this curve.Methods: Data from 20 patients with rNPC receiving carbon-ion radiotherapy (CIRT) in our hospital were collected. LEM in Raystation (V8A, Raystation, Sweden) was used to generate treatment plans. The clinical target volume CTV1（GTV+5mm）was given 3 Gy (RBE) per fraction. Ninety-nine percent of target volumes should be covered by 95% of the prescriptions; the maximum doses of the brainstem and spinal cord were < 45 Gy (RBE) and < 30 Gy (RBE), respectively. The doses covering 20% volumes of optical nerves/chiasms D20 were < 30 Gy (RBE). Then physical doses of the LEM plans were recalculated by using MKM in Raystation to generate MKM plans. A series of conversion factors (i.e., the ratio of LEM RBE-weighted dose to MKM RBE-weighted dose) was then obtained by using an isovolumetric dose method. The LEM plan prescriptions (LEM prescription) and dose constraints of the organs at risk (OARs) (OAR constraints) were converted to the corresponding MKM prescriptions and dose constraints using this conversion curve. Results: For the CTV1 fractional RBE-weighted dose prescription of 3.00 Gy (RBE) and CTV2 of 2.70 Gy (RBE) in LEM plans, the conversion factors (LEM RBE-weighted dose/MKM RBE-weighted dose) were 1.37 (CI 95％ 1.35–1.39) and 1.46 (1.41–1.51), respectively. The average conversion factors from 1.37(CI 95％ 1.33–1.41) to 3.09 (2.94–3.24) corresponded to the LEM fractionated doses from 2.86 Gy (RBE) to 0.24 Gy (RBE), including the doses constraining upon OARs. LEM RBE-weighted doses of 30 Gy (RBE) and 45 Gy (RBE) in 21 fractions were converted to MKM RBE-weighted doses of 16.64 Gy (RBE) and 30.72 Gy (RBE) in 16 fractions. Conclusions: This conversion curve could be used to convert LEM RBE-weighted doses to MKM RBE-weighted doses for patients with rNPC receiving CIRT, providing dose references for re-irradiation therapy.

scholarly journals Conversion and Validation of Rectal Constraints for Prostate Carcinoma Receiving Hypofractionated Carbon-ion Radiotherapy With a Local Effect Model

2020 ◽  
Author(s):  
Weiwei Wang ◽  
Ping Li ◽  
Yinxiangzi Sheng ◽  
Zhijie Huang ◽  
Jingfang Zhao ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Prostate Carcinoma ◽  
Local Effect ◽  
Carbon Ion Radiotherapy ◽  
Study Objective ◽  
Carbon Ion ◽  
Conversion Model ◽  
Biophysical Models ◽  
Effect Model

Abstract Purpose: The study objective was to convert the microdosimetric kinetic model (MKM) rectum constraints for 16-fraction carbon-ion radiotherapy (CIRT) to local effect model (LEM) constraints for 12-fraction, 8-fraction, and 4-fraction CIRT for prostate carcinoma patients (PCAs).Methods: Two strategies were employed. To understand the fractionation effects, MKM linear-quadric (LQ) strategy first converted MKM rectum constraints for 16-fraction CIRT to 12-fraction, 8-fraction, and 4-fraction CIRT. To examine the differences in the biophysical models, MKM constraints were converted to LEM constraints using an RBE-conversion model. The LEM LQ strategy first converted MKM rectum constraints for 16-fraction CIRT to LEM constraints using the RBE-conversion model. Then, the LEM constraints converted the 16-fraction constraints to the rectum constraints for 12-fraction, 8-fraction, and 4-fraction CIRT using the LQ model. The LEM rectum constraints for 16 and 12-fraction CIRTs were compared to the rectum doses and the clinical follow-ups in 40 patients.Results: The 16-fraction NIRS rectum constraint Dmax < 60.8 Gy(RBE) and CNAO rectum constraint D1cc < 66.00 Gy(RBE) were converted by MKM LQ strategy to LEM constraints 58.01 and 55.97 Gy(RBE) (12fx), 45.47 and 43.97 Gy(RBE) (8fx), and 29.64 and 28.67 Gy(RBE) (4fx) and by LEM LQ strategy to 61.73 and 59.69 Gy(RBE) (12fx), 53.03 and 51.33 Gy(RBE) (8fx), and 40.10 and 38.88 Gy(RBE) (4fx). Differences of 36.13% were found. No late rectum complications were reported.Conclusions: The LEM rectum constraints from MKM LQ strategy were more conservative and can be used as the reference constraints for starting the hypofractionated CIRT.

scholarly journals RBE-weighted dose conversions for patients with recurrent nasopharyngeal carcinoma receiving carbon-ion radiotherapy from the local effect model to the microdosimetric kinetic model

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Liwen Zhang ◽  
Weiwei Wang ◽  
Jiyi Hu ◽  
Jiade Lu ◽  
Lin Kong
Keyword(s):  
Spinal Cord ◽  
Nasopharyngeal Carcinoma ◽  
Kinetic Model ◽  
Local Effect ◽  
Carbon Ion Radiotherapy ◽  
Conversion Factors ◽  
Carbon Ion ◽  
Effect Model ◽  
Recurrent Nasopharyngeal Carcinoma ◽  
Dose Constraints

Abstract Background We sought to establish a conversion curve to convert the RBE-weighted doses calculated by local effect model I (LEM) (LEM RBE-weighted doses) in patients with locally recurrent nasopharyngeal carcinoma (rNPC) to the RBE-weighted doses calculated by microdosimetric kinetic model (MKM) (MKM RBE-weighted doses). We also converted the LEM dose constraints (RBE-weighted dose constraints in LEM plans) for the brain stem, spinal cord, and optic nerve based on this curve. Methods Data from 20 patients with rNPC receiving carbon-ion radiotherapy (CIRT) in our hospital were collected. LEM in Raystation (V8A, Raystation, Sweden) was used to generate treatment plans. The clinical target volume CTV1 (GTV + 5 mm) was given 3 Gy (RBE) per fraction. Ninety-nine percent of target volumes should be covered by 95% of the prescriptions; the maximum doses of the brainstem and spinal cord were < 45 Gy (RBE) and < 30 Gy (RBE), respectively. The doses covering 20% volumes of optical nerves/chiasms D20 were < 30 Gy (RBE). Then physical doses of the LEM plans were recalculated by using MKM in Raystation to generate MKM plans. A series of conversion factors (i.e., the ratio of LEM RBE-weighted dose to MKM RBE-weighted dose) was then obtained by using an isovolumetric dose method. The LEM plan prescriptions (LEM prescription) and dose constraints of the organs at risk (OARs) (OAR constraints) were converted to the corresponding MKM prescriptions and dose constraints using this conversion curve. Results For the CTV1 fractional RBE-weighted dose prescription of 3.00 Gy (RBE) and CTV2 of 2.70 Gy (RBE) in LEM plans, the conversion factors (LEM RBE-weighted dose/MKM RBE-weighted dose) were 1.37 (CI 95% 1.35–1.39) and 1.46 (1.41–1.51), respectively. The average conversion factors from 1.37 (CI 95% 1.33–1.41) to 3.09 (2.94–3.24) corresponded to the LEM fractionated doses from 2.86 Gy (RBE) to 0.24 Gy (RBE), including the doses constraining upon OARs. LEM RBE-weighted doses of 30 Gy (RBE) and 45 Gy (RBE) in 21 fractions were converted to MKM RBE-weighted doses of 16.64 Gy (RBE) and 30.72 Gy (RBE) in 16 fractions. Conclusions This conversion curve could be used to convert LEM RBE-weighted doses to MKM RBE-weighted doses for patients with rNPC receiving CIRT, providing dose references for re-irradiation therapy.

Analysis of the reliability of the local effect model for the use in carbon ion treatment planning systems

2010 ◽  
Vol 143 (2-4) ◽  
pp. 497-502 ◽  
Author(s):  
G. Russo ◽  
A. Attili ◽  
F. Bourhaleb ◽  
F. Marchetto ◽  
C. Peroni ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Local Effect ◽  
Planning Systems ◽  
Carbon Ion ◽  
Treatment Planning Systems ◽  
Effect Model ◽  
Ion Treatment

scholarly journals A DNA Double-Strand Break Kinetic Rejoining Model Based on the Local Effect Model

2013 ◽  
Vol 180 (5) ◽  
pp. 524-538 ◽  
Author(s):  
F. Tommasino ◽  
T. Friedrich ◽  
U. Scholz ◽  
G. Taucher-Scholz ◽  
M. Durante ◽  
...  
Keyword(s):  
Strand Break ◽  
Double Strand Break ◽  
Local Effect ◽  
Model Based ◽  
Effect Model ◽  
Dna Double Strand Break

Local effect model development for the steam generator three dimensional thermal hydraulics analysis code

2020 ◽  
Vol 136 ◽  
pp. 107020 ◽  
Author(s):  
Xi Wang ◽  
Mingjun Wang ◽  
Ge Wu ◽  
Jing Zhang ◽  
Suizheng Qiu ◽  
...  
Keyword(s):  
Steam Generator ◽  
Model Development ◽  
Three Dimensional ◽  
Local Effect ◽  
Thermal Hydraulics ◽  
Effect Model
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