scholarly journals The effect of 6 and 15 MV on intensity-modulated radiation therapy prostate cancer treatment: plan evaluation, tumour control probability and normal tissue complication probability analysis, and the theoretical risk of secondary induced malignancies

2012 ◽  
Vol 85 (1012) ◽  
pp. 423-432 ◽  
Author(s):  
M Hussein ◽  
S Aldridge ◽  
T Guerrero Urbano ◽  
A Nisbet
Keyword(s):  
Normal Tissue ◽  
Treatment Plan ◽  
Intensity Modulated Radiation Therapy ◽  
Normal Tissue Complication Probability ◽  
Prostate Cancer Treatment ◽  
Plan Evaluation ◽  
Tumour Control ◽  
Tumour Control Probability ◽  
Treatment Plan Evaluation ◽  
Theoretical Risk

scholarly journals Analysis of NTCP Based Radiobiological Models: A Systematic Review of Literatures

2019 ◽  
Vol 4 (4) ◽  
Keyword(s):  
Normal Tissue ◽  
Treatment Plan ◽  
Parallel Architecture ◽  
Critical Volume ◽  
Planning System ◽  
Critical Element ◽  
Plan Evaluation ◽  
Response Models ◽  
Radiobiological Models ◽  
Treatment Plan Evaluation

To achieve the optimal treatment goal, radiobiological parameters have to evaluate and predict the outcome of this treatment plan in terms of both TCP and NTCP. Different types of radiobiological model were used to achieve prescribed treatment dose of radiation during the tumor control. Where TCP models play an important role in order to achieve desired dose to the tumor. A suitable NTCP model was theoretically found among different models that can be used in treatment plan evaluation. Theoretically, six different radiobiological dose response models were analyzed in this project. Lyman–Kutcher–Burman, Critical element, critical volume, Relative Seriality, Parallel architecture, Weibull distribution models were analyzed from the derivation. All models were discussed elaborately with its various parameters and were used in the calculation of normal tissue complication probability during the treatment in radiotherapy. Further, all models were compared with each other. The models denote the dose for 50% complication probability (D50) parameters is the most commonly used radiobiological models for the normal tissues. The functional subunit response models (critical element & Relative seriality, Critical Volume, parallel architecture) are used in the derivation of the formulae for the normal tissue. Since all complicated NTCP model predict same as the simple NTCP model that is Lyman–Kutcher–Burman model as well as it is computationally efficient. Also Lyman–Kutcher–Burman model can be used in different treatment planning system incorporating with other model. For this reason, our suggested model is Lyman–Kutcher–Burman NTCP model which can be used in treatment plan evaluation. After analyzing six different model of NTCP, finding of the study is the treatment plan evaluation in where Lyman–Kutcher–Burman model is the best model for biological plan evaluation.

scholarly journals Monte Carlo Calculation of Radioimmunotherapy with90Y-,177Lu-,131I-,124I-, and188Re-Nanoobjects: Choice of the Best Radionuclide for Solid Tumour Treatment by Using TCP and NTCP Concepts

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
S. Lucas ◽  
O. Feron ◽  
B. Gallez ◽  
B. Masereel ◽  
C. Michiels ◽  
...  
Keyword(s):  
Treatment Efficacy ◽  
Solid Tumour ◽  
Normal Tissue ◽  
Monte Carlo Calculation ◽  
Normal Tissue Complication Probability ◽  
Small Cell ◽  
Small Cell Lung ◽  
Tumour Control ◽  
Improve Treatment ◽  
Tumour Control Probability

Radioimmunotherapy has shown that the use of monoclonal antibodies combined with a radioisotope like131I or90Y still remains ineffective for solid and radioresistant tumour treatment. Previous simulations have revealed that an increase in the number of90Y labelled to each antibody or nanoobject could be a solution to improve treatment output. It now seems important to assess the treatment output and toxicity when radionuclides such as90Y,177Lu,131I,124I, and188Re are used. Tumour control probability (TCP) and normal tissue complication probability (NTCP) curves versus the number of radionuclides per nanoobject were computed with MCNPX to evaluate treatment efficacy for solid tumours and to predict the incidence of surrounding side effects. Analyses were carried out for two solid tumour sizes of 0.5 and 1.0 cm radius and for nanoobject (i.e., a radiolabelled antibody) distributed uniformly or nonuniformly throughout a solid tumour (e.g., Non-small-cell-lung cancer (NSCLC)).90Y and188Re are the best candidates for solid tumour treatment when only one radionuclide is coupled to one carrier. Furthermore, regardless of the radionuclide properties, high values of TCP can be reached without toxicity if the number of radionuclides per nanoobject increases.

scholarly journals Methods to calculate normal tissue complication and tumour control probabilities for fractionated inhomogeneous dose distribution of intensity-modulated radiation therapy

2008 ◽  
Vol 7 (3) ◽  
pp. 151-157 ◽  
Author(s):  
T.S. Kehwar ◽  
Anup K. Bhardwaj
Keyword(s):  
Radiation Therapy ◽  
Cell Density ◽  
Normal Tissue ◽  
Intensity Modulated Radiation Therapy ◽  
Normal Tissue Complication Probability ◽  
Tumour Control ◽  
Intensity Modulated ◽  
Cell Densities ◽  
Clonogenic Cell ◽  
Radio Sensitivity

AbstractObjectives: This study is designed to present and evaluate radiobiological-based dose–volume histogram (DVH) reduction schemes to calculate normal tissue complication probability (NTCP) and tumour control probability (TCP) for intensity-modulated radiation therapy (IMRT).Methods: The proposed DVH reduction schemes were derived for 2 Gy per fraction and prescribed dose per fraction for critical organs and tumours, respectively. Sample computed tomography scans were used to generate two IMRT plans to deliver 54 Gy to PTV1 and 24 Gy to PTV2 via sequential IMRT boost (SqIB) and simultaneous integrated IMRT boost (SIB) plans. Differential DVHs were used to calculate effective volumes using published values of related parameters of critical organs and prostate.Results: NTCP values for bladder were almost zero for both IMRT plans. The plots between k and NTCP for rectum and femurs (k = 0.1–1.0) show higher NTCP for SqIB than that for SIB. The TCP decreases with increasing clonogenic cell density and is higher for SIB than that for SqIB for all clonogenic cell densities. The value of α proposed by Brenner and Hall shows very low radio sensitivity of clonogens of the prostate, which gives very low TCP for conventional doses of 70–80 Gy delivered in 7–8 weeks, even for very low clonogenic cell density in the prostate.Conclusion: The presented DVH reduction schemes have radiobiological bearing and therefore seem to be effective in calculating fairly accurate NTCP and TCP.

scholarly journals Theoretical derivation and clinical dose-response quantification of a unified multi-activation (UMA) model of cell survival from a logistic equation

BJR|Open ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Shidong Li
Keyword(s):  
Cell Survival ◽  
Normal Tissue ◽  
Dose Range ◽  
Normal Tissue Complication Probability ◽  
Order Reaction ◽  
Second Order Reaction ◽  
X Ray ◽  
Tumour Control ◽  
Tumour Control Probability ◽  
X Ray Imaging

Objective: To theoretically derive a unified multiactivation (UMA) model of cell survival after ionising radiation that can accurately assess doses and responses in radiotherapy and X-ray imaging. Methods: A unified formula with only two parameters in fitting of a cell survival curve (CSC) is first derived from an assumption that radiation-activated cell death pathways compose the first- and second-order reaction kinetics. A logit linear regression of CSC data is used for precise determination of the two model parameters. Intrinsic radiosensitivity, biologically effective dose (BED), equivalent dose to the traditional 2 Gy fractions (EQD2), tumour control probability, normal-tissue complication probability, BED50 and steepness (Γ50) at 50% of tumour control probability (or normal-tissue complication probability) are analytical functions of the model and treatment (or imaging) parameters. Results: The UMA model has almost perfectly fit typical CSCs over the entire dose range with R2≥0.99. Estimated quantities for stereotactic body radiotherapy of early stage lung cancer and the skin reactions from X-ray imaging agree with clinical results. Conclusion: The proposed UMA model has theoretically resolved the catastrophes of the zero slope at zero dose for multiple target model and the bending curve at high dose for the linear quadratic model. More importantly, it analytically predicts dose–responses to various dose–fraction schemes in radiotherapy and to low dose X-ray imaging based on these preclinical CSCs. Advances in knowledge: The discovery of a unified formula of CSC over the entire dose range may reveal a common mechanism of the first- and second-order reaction kinetics among multiple CD pathways activated by ionising radiation at various dose levels.

scholarly journals Influence of Urethra Sparing on Tumor Control Probability and Normal Tissue Complication Probability in Focal Dose Escalated Hypofractionated Radiotherapy: A Planning Study Based on Histopathology Reference

2021 ◽  
Vol 11 ◽  
Author(s):  
Simon K. B. Spohn ◽  
Ilias Sachpazidis ◽  
Rolf Wiehle ◽  
Benedikt Thomann ◽  
August Sigle ◽  
...  
Keyword(s):  
Dose Escalation ◽  
Normal Tissue ◽  
Normal Tissue Complication Probability ◽  
Tumor Control ◽  
Planning Study ◽  
Tumour Control ◽  
Tumour Control Probability ◽  
Psma Pet ◽  
Pet Ct ◽  
Dose Constraints

PurposeMultiparametric magnetic resonance tomography (mpMRI) and prostate specific membrane antigen positron emission tomography (PSMA-PET/CT) are used to guide focal radiotherapy (RT) dose escalation concepts. Besides improvements of treatment effectiveness, maintenance of a good quality of life is essential. Therefore, this planning study investigates whether urethral sparing in moderately hypofractionated RT with focal RT dose escalation influences tumour control probability (TCP) and normal tissue complication probability (NTCP).Patients and Methods10 patients with primary prostate cancer (PCa), who underwent 68Ga PSMA-PET/CT and mpMRI followed by radical prostatectomy were enrolled. Intraprostatic tumour volumes (gross tumor volume, GTV) based on both imaging techniques (GTV-MRI and -PET) were contoured manually using validated contouring techniques and GTV-Union was created by summing both. For each patient three IMRT plans were generated with 60 Gy to the whole prostate and a simultaneous integrated boost up to 70 Gy to GTV-Union in 20 fractions by (Plan 1) not respecting and (Plan 2) respecting dose constraints for urethra as well as (Plan 3) respecting dose constraints for planning organ at risk volume for urethra (PRV = urethra + 2mm expansion). NTCP for urethra was calculated applying a Lyman-Kutcher-Burman model. TCP-Histo was calculated based on PCa distribution in co-registered histology (GTV-Histo). Complication free tumour control probability (P+) was calculated. Furthermore, the intrafractional movement was considered.ResultsMedian overlap of GTV-Union and PRV-Urethra was 1.6% (IQR 0-7%). Median minimum distance of GTV-Histo to urethra was 3.6 mm (IQR 2 – 7 mm) and of GTV-Union to urethra was 1.8 mm (IQR 0.0 – 5.0 mm). The respective prescription doses and dose constraints were reached in all plans. Urethra-sparing in Plans 2 and 3 reached significantly lower NTCP-Urethra (p = 0.002) without significantly affecting TCP-GTV-Histo (p = p > 0.28), NTCP-Bladder (p > 0.85) or NTCP-Rectum (p = 0.85), resulting in better P+ (p = 0.006). Simulation of intrafractional movement yielded even higher P+ values for Plans 2 and 3 compared to Plan 1.ConclusionUrethral sparing may increase the therapeutic ratio and should be implemented in focal RT dose escalation concepts.

scholarly journals A Brachytherapy Plan Evaluation Tool for Interstitial Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Surega Anbumani ◽  
N. Arunai Nambiraj ◽  
Sridhar Dayalan ◽  
Kalaivany Ganesh ◽  
Pichandi Anchineyan ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Treatment Plan ◽  
Predictive Ability ◽  
Normal Tissue Complication Probability ◽  
Tumor Control ◽  
Tumor Control Probability ◽  
Evaluation Tool ◽  
Equivalent Uniform Dose ◽  
Plan Evaluation ◽  
Dose Volume Histograms

Radiobiological metrics such as tumor control probability (TCP) and normal tissue complication probability (NTCP) help in assessing the quality of brachytherapy plans. Application of such metrics in clinics as well as research is still inadequate. This study presents the implementation of two indigenously designed plan evaluation modules: Brachy_TCP and Brachy_NTCP. Evaluation tools were constructed to compute TCP and NTCP from dose volume histograms (DVHs) of any interstitial brachytherapy treatment plan. The computation module was employed to estimate probabilities of tumor control and normal tissue complications in ten cervical cancer patients based on biologically effective equivalent uniform dose (BEEUD). The tumor control and normal tissue morbidity were assessed with clinical followup and were scored. The acute toxicity was graded using common terminology criteria for adverse events (CTCAE) version 4.0. Outcome score was found to be correlated with the TCP/NTCP estimates. Thus, the predictive ability of the estimates was quantified with the clinical outcomes. Biologically effective equivalent uniform dose-based formalism was found to be effective in predicting the complexities and disease control.

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