scholarly journals Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) in Mono and Dual-isocentric Techniques of Breast Cancer Radiation Therapy

2021 ◽  
pp. 192-202
Author(s):  
Kaveh Shirani Tak Abi ◽  
Sediqeh Habibian ◽  
Marzieh Salimi ◽  
Ahmad Shakeri ◽  
Mohammad Mehdi Mojahed ◽  
...  
Keyword(s):  
Breast Cancer ◽  
At Risk ◽  
Radiation Therapy ◽  
Normal Tissue ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Normal Tissue Complication Probability ◽  
The Other ◽  
Tumor Control ◽  
Tumor Control Probability

Background: Nowadays, radiation therapy plays an important role in the treatment of breast cancer. The important point is the optimal control of the tumor along with the protection of organs at risk. This study aims to investigate and compare the radiobiological factors of the tumor and organs at risk in two different radiation therapy techniques of breast cancer.Methods: Ten left-sided breast cancer patients with breast-conservative surgery were selected for this study. Three-dimensional treatment planning was performed using CT scan images of the patients using PCRT 3D software. Two different tangential external beam techniques were compared: first, dual-isocentric technique (DIT) with two isocentre, one on the breast tissue, and the other one on the supraclavicular lymph nodes and second, a mono-isocentric technique (MIT) with one isocentre at the intersection of the tangential and the supraclavicular field. The total prescribed dose was 5000 cGy per 25 fractions. Dose-volume histograms (DVHs), Tumor control probability (TCP), and normal tissue complication probability (NTCP) curves were used to compare the dosimetric and radiobiological parameters of the tissues in the prementioned techniques. Results: The results showed that the maximum doses in planning target volume (PTV) with mean values of 109% and 110% in the SI and DIT were not significantly different in both techniques and that they were indeed at the optimum level based on the RTOG 1005 protocol. The dose homogeneity index in MMIT was more than that in DIT, while the conformity index and the mean TCP did not show a significant difference in the two techniques. Furthermore, minimum, mean, and maximum dose in the lung and the probability of pneumonitis decreased in MIT. On the other hand, the maximum dose, the dose of 33%, 66%, and 100% of the heart, and the probability of pericarditis in MIT were lower than the figure in DIT. Conclusion: Due to the absence of hot spots at the intersection of tangential and supraclavicular fields and the reduction of mechanical movements of the coach and collimator in MIT, the superiority of this method was confirmed.

scholarly journals Evaluation of various common prostate IMRT techniques based on estimated tumor control and normal tissue complication probabilities in correlation with patients anatomical parameters derived from the CT scans

2019 ◽  
Vol 25 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Amin Banaei ◽  
Bijan Hashemi ◽  
Mohsen Bakhshandeh ◽  
Bahram Mofid
Keyword(s):  
Normal Tissue ◽  
Organs At Risk ◽  
Normal Tissue Complication Probability ◽  
Ct Scans ◽  
Tumor Control ◽  
P Value ◽  
Target Tissue ◽  
Tumor Control Probability ◽  
Radiobiological Effects ◽  
Anatomical Parameters

Abstract Background: The relationship between the prostate IMRT techniques and patients anatomical parameters has been rarely investigated. Objective: to evaluate various prostate IMRT techniques based on tumor control and normal tissue complication probability (TCP and NTCP) values and also the correlation of such techniques with patients anatomical parameters. Methods: Four IMRT techniques (9, 7 and 5 fields and also automatic) were planned on the CT scans of 63 prostate cancer patients. The sum of distances between the organs at risk (OARs) and target tissue and also their average joint volumes were measured and assumed as anatomical parameters. Selected dosimetric and radiobiological parameters (TCP and NTCP) values were compared among various techniques and the correlation with the above anatomical parameters were assessed using Pearsons’ correlation. Results: High correlations were found between the dosimetric/radiobiological parameters of OARs with the joint volumes and with the distances between the OARs and target tissue in all the techniques. The TCP and complication free tumor control probability (P+) values were decreased with increasing the joint volume and decreasing the distances between the OARs and target tissue (as poly-nominal functions). The NTCP values were increased with increasing the joint volumes and decreasing the distances (3-degree poly-nominal functions). For the low percent joint volumes (<20%) and high distances (>7 cm), The TCP, NTCP and P+ showed no statistical differences between various techniques (P-value>0.07). However, 9 and 7 fields techniques indicated better radiobiological results (P-value<0.05) in almost other ranges (>20% joint volumes and <7 cm distances). Conclusion: Based on our results, it would be possible to compare radiobiological effects of various common IMRT techniques and choose the best one regarding to patients anatomical parameters derived from the CT scans.

scholarly journals Investigation of whether in-room CT-based adaptive intracavitary brachytherapy for uterine cervical cancer is robust against interfractional location variations of organs and/or applicators

2016 ◽  
Vol 57 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Yoshifumi Oku ◽  
Hidetaka Arimura ◽  
Tran Thi Thao Nguyen ◽  
Yoshiyuki Hiraki ◽  
Masahiko Toyota ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Radiation Treatment ◽  
Organs At Risk ◽  
Normal Tissue Complication Probability ◽  
Uterine Cervical Cancer ◽  
Intracavitary Brachytherapy ◽  
Conformity Index ◽  
Tumor Control ◽  
Tumor Control Probability ◽  
Target Volumes

Abstract This study investigates whether in-room computed tomography (CT)-based adaptive treatment planning (ATP) is robust against interfractional location variations, namely, interfractional organ motions and/or applicator displacements, in 3D intracavitary brachytherapy (ICBT) for uterine cervical cancer. In ATP, the radiation treatment plans, which have been designed based on planning CT images (and/or MR images) acquired just before the treatments, are adaptively applied for each fraction, taking into account the interfractional location variations. 2D and 3D plans with ATP for 14 patients were simulated for 56 fractions at a prescribed dose of 600 cGy per fraction. The standard deviations (SDs) of location displacements (interfractional location variations) of the target and organs at risk (OARs) with 3D ATP were significantly smaller than those with 2D ATP (P &lt; 0.05). The homogeneity index (HI), conformity index (CI) and tumor control probability (TCP) in 3D ATP were significantly higher for high-risk clinical target volumes than those in 2D ATP. The SDs of the HI, CI, TCP, bladder and rectum D2cc, and the bladder and rectum normal tissue complication probability (NTCP) in 3D ATP were significantly smaller than those in 2D ATP. The results of this study suggest that the interfractional location variations give smaller impacts on the planning evaluation indices in 3D ATP than in 2D ATP. Therefore, the 3D plans with ATP are expected to be robust against interfractional location variations in each treatment fraction.

Normal-tissue toxicities of thoracic radiation therapy: esophagus, lung, and spinal cord as organs at risk

2004 ◽  
Vol 18 (1) ◽  
pp. 131-160 ◽  
Author(s):  
Maria Werner-Wasik ◽  
Xiaoli Yu ◽  
Lawrence B Marks ◽  
Timothy E Schultheiss
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Radiation Therapy ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Thoracic Radiation

scholarly journals Can volumetric modulated arc radiation therapy reduce organ at risk dose in stage 4 sinonasal tumors in dogs treated with boost irradiation?

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0259112
Author(s):  
Valeria Meier ◽  
Felicitas Czichon ◽  
Linda Walsh ◽  
Carla Rohrer Bley
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Degrees Of Freedom ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
Normal Tissue Complication Probability ◽  
Lacrimal Glands ◽  
Stage 4

Intensity modulated radiation therapy (IMRT) introduced marked changes to cancer treatment in animals by reducing dose to organs at risk (OAR). As the next technological step, volumetric modulated arc therapy (VMAT) has advantages (increased degrees-of-freedom, faster delivery) compared to fixed-field IMRT. Our objective was to investigate a possible advantage of VMAT over IMRT in terms of lower OAR doses in advanced-disease sinonasal tumors in dogs treated with simultaneously-integrated boost radiotherapy. A retrospective, analytical, observational study design was applied using 10 pre-existing computed tomography datasets on dogs with stage 4 sinonasal tumors. Each dataset was planned with both, 5-field IMRT and 2 arc VMAT with 10x4.83 Gy to the gross tumor volume and 10x4.2 Gy to the planning target volume. Adequate target dose coverage and normal tissue complication probability of brain ≤5% was required. Dose constraints aspired to were D60 <15 Gy for eyes, D2 <35.4 Gy for corneae, and Dmean <20 Gy for lacrimal glands. OAR dose was statistically significantly higher in IMRT plans than in VMAT plans. Median eye D60% was 18.5 Gy (interquartile range (IQR) 17.5) versus 16.1 Gy (IQR 7.4) (p = 0.007), median lacrimal gland dose 21.8 Gy (IQR 20.5) versus 18.6 Gy (IQR 7.0) (p = 0.013), and median cornea D2% 45.5 Gy (IQR 6.8) versus 39.9 Gy (IQR 10.0) (p<0.005) for IMRT versus VMAT plans, respectively. Constraints were met in 21/40 eyes, 7/40 corneae, and 24/40 lacrimal glands. Median delivery time was significantly longer for IMRT plans than for VMAT plans (p<0.01). Based on these results, VMAT plans were found to be superior in sparing doses to eyes, lacrimal glands, corneae. However, not all ocular OAR constraints could be met while ensuring adequate dose coverage and restricting brain toxicity risk for both planning techniques.

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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