scholarly journals Comparison of Ray Tracing and Monte Carlo Calculation Algorithms for Spine Lesions Treated with CyberKnife

2021 ◽  
Author(s):  
Jun Li ◽  
Xile Zhang ◽  
Yuxi Pan ◽  
Hongqing Zhuang ◽  
Ruijie Yang
Keyword(s):  
At Risk ◽  
Monte Carlo ◽  
Ray Tracing ◽  
Thoracic Spine ◽  
Organs At Risk ◽  
Target Coverage ◽  
Dose Volume Histograms ◽  
Percentage Volume ◽  
Calculation Algorithms ◽  
Sacral Spine

Abstract Purpose: This study attempts to evaluate Ray Tracing (RT) and Monte Carlo (MC) algorithm for CyberKnife treatments of spine lesions and determine whether MC algorithm is necessary for all spine treatment and analyze which sites of spine lesion for which RT algorithm is comparable to MC algorithm. Methods: The CyberKnife is used for stereotactic body radiotherapy for lesions in the cervical spine (30), thoracic spine (50), lumbar spine (30) and sacral spine (15). Dose was calculated using RT and MC algorithms for patients planned with the same beam angles and monitor units. Dose-volume histograms of the target and selected critical structures are evaluated. Results: The average target coverage of prescribed dose with MC algorithms was 94.80%, 88.47%, 92.52% and 93.41% respectively in cervical, thoracic, lumbar and sacral spine. For thoracic spine, RT algorithm significantly overestimates the percentage volume of target covered by the prescribed dose, as well as overestimates doses to organs at risk in most cases, including lung, spinal cord and esophagus. For cervical, lumbar and sacral spine, the differences of the target coverage of prescription dose were generally less than 3% between the RT and MC algorithms. The differences of doses to organs at risk varied with lesion sites and surrounding organs. Conclusions: In the thoracic spine lesions with beams through air cavities, RT algorithm should be limited and verified with MC algorithm, but the RT algorithm is adequate for treatment of cervical, lumbar and sacral spine lesions without or small amount of beams passing through the lungs.

Evaluation of plan optimisers in prostate VMAT using the dose distribution index

2019 ◽  
Vol 18 (4) ◽  
pp. 323-328 ◽  
Author(s):  
James C. L. Chow ◽  
Runqing Jiang ◽  
Lu Xu
Keyword(s):  
At Risk ◽  
Dose Distribution ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Weighting Factor ◽  
Target Coverage ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Distribution Index

AbstractPurpose:Dose distribution index (DDI) is a treatment planning evaluation parameter, reflecting dosimetric information of target coverage that can help to spare organs at risk (OARs) and remaining volume at risk (RVR). The index has been used to evaluate and compare prostate volumetric modulated arc therapy (VMAT) plans using two different plan optimisers, namely photon optimisation (PO) and its predecessor, progressive resolution optimisation (PRO).Materials and methods:Twenty prostate VMAT treatment plans were created using the PO and PRO in this retrospective study. The 6 MV photon beams and a dose prescription of 78 Gy/39 fractions were used in plans with the same dose–volume criteria for plan optimisation. Dose–volume histograms (DVHs) of the planning target volume (PTV), as well as of OARs such as the rectum, bladder, left and right femur were determined in each plan. DDIs were calculated and compared for plans created by the PO and PRO based on DVHs of the PTV and all OARs.Results:The mean DDI values were 0·784 and 0·810 for prostate VMAT plans created by the PO and PRO, respectively. It was found that the DDI of the PRO plan was about 3·3% larger than the PO plan, which means that the dose distribution of the target coverage and sparing of OARs in the PRO plan was slightly better. Changing the weighting factors in different OARs would vary the DDI value by ∼7%. However, for plan comparison based on the same set of dose–volume criteria, the effect of weighting factor can be neglected because they were the same in the PO and PRO.Conclusions:Based on the very similar DDI values calculated from the PO and PRO plans, with the DDI value in the PRO plan slightly larger than that of the PO, it may be concluded that the PRO can create a prostate VMAT plan with slightly better dose distribution regarding the target coverage and sparing of OARs. Moreover, we found that the DDI is a simple and comprehensive dose–volume parameter for plan evaluation considering the target, OARs and RVR.

A deep learning model to predict dose–volume histograms of organs at risk in radiotherapy treatment plans

2020 ◽  
Vol 47 (11) ◽  
pp. 5467-5481
Author(s):  
Zhiqiang Liu ◽  
Xinyuan Chen ◽  
Kuo Men ◽  
Junlin Yi ◽  
Jianrong Dai
Keyword(s):  
At Risk ◽  
Deep Learning ◽  
Organs At Risk ◽  
Learning Model ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Treatment Plans ◽  
Deep Learning Model ◽  
Radiotherapy Treatment

scholarly journals Comparison of treatment plans calculated by Ray Tracing and Monte Carlo algorithms for head and thorax radiotherapy with Cyberknife

2017 ◽  
Vol 3 (2) ◽  
pp. 647-650 ◽  
Author(s):  
Kirsten Galonske ◽  
Martin Thiele ◽  
Iris Ernst ◽  
Ralph Lehrke ◽  
Waldemar Zylka
Keyword(s):  
Monte Carlo ◽  
Ray Tracing ◽  
Stereotactic Radiotherapy ◽  
Calculation Algorithm ◽  
Monte Carlo Algorithms ◽  
Body Regions ◽  
Calculation Algorithms ◽  
Treatment Plans ◽  
Homogeneous Regions ◽  
Tumor Types

AbstractThis study investigates differences between treatment plans generated by Ray Tracing (RT) and Monte Carlo (MC) calculation algorithms in homogeneous and heterogeneous body regions. Particularly, we focus on the head and on the thorax, respectively, for robotic stereotactic radiotherapy and radiosurgery with Cyberknife. Radiation plans for tumors located in the head and in the thorax region have been calculated and compared to each other in 47 cases and several tumor types.Assuming MC as the algorithm of highest accuracy it is shown that based on selected dose parameters, RT slightly underestimates the dose in homogeneous regions and overestimates in heterogeneous regions. In addition, deviations occur due to tumor size rendering large differences for small tumors. We conclude that dose prescriptions for radiotherapy treatments should differentiate between RT and MC calculation algorithm. This is especially important for small tumors in heterogeneous body regions.

The Advantages of Active Breathing Coordinator Device During Left-Sided Breast Cancer Radiation Therapy: A Dosimetric Comparison Study

2020 ◽  
Author(s):  
Nadia Pasinetti ◽  
Lilia Bardoscia ◽  
Luigi Spiazzi ◽  
Barbara Ghedi ◽  
Sara Pedretti ◽  
...  
Keyword(s):  
Breast Cancer ◽  
At Risk ◽  
Side Effects ◽  
Organs At Risk ◽  
Left Lung ◽  
Normal Tissue Complication Probability ◽  
Left Breast ◽  
Breath Hold ◽  
Deep Inspiration Breath Hold ◽  
Dose Volume Histograms

Abstract Background: Radiotherapy (RT) improves local control and survival in breast cancer (BC) patients. However, risk of heart and lung side effects after post-operative left breast RT for breast cancer remain despite technological and technical RT advances. In a retrospective cohort we investigated if Active Breathing Coordinator (ABC) device can reduce risk of cardiopulmonary morbidity.Methods: we performed two different dosimetric analyses by Normal Tissue Complication Probability (NTCP) and Bio-Dose-Volume Histograms (Bio-DVH) in order to determine whether left breast RT using moderating deep inspiration breath-hold (mDIBH) with the Active Breathing Coordinator (ABC) device, may significantly reduce heart, left anterior descending coronary artery (LADCA) and lung radiation exposure during left breast RT performed with 3d-CRT technique.Results: Several dosimetric parameters were used in the present study to compare the treatment plans generated by FB and mDIBH images of sixty-nine consecutive patients treated between May 2012 and April 2016 at the Istituto del Radio Radiation Oncology Dept. All data derived by Bio-DVH and the heart NTCP calculation showed that ABC led to significant sparing of organs at risk compared with FB, expecially for the heart and LADCA. We also showed that the mDIBH technique significantly reduced left lung dose: in fact, through inflation, only low density lung tissue remains within the tangential field, thus avoiding its deterioration.Conclusions: Use of mDIBH gives a real advantage on breast cancer RT by reducing the radiation to the organs at risk (OARs) and consequently, the risk of cardiac and pulmonary late side effects.

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