scholarly journals Volume-based algorithm of lung dose optimization in novel dynamic arc radiotherapy for esophageal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kuan-Heng Lin ◽  
Chen-Xiong Hsu ◽  
Shan-Ying Wang ◽  
Greta S. P. Mok ◽  
Chiu-Han Chang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Esophageal Cancer ◽  
Maximum Dose ◽  
Treatment Plan ◽  
Conformity Index ◽  
Lung Dose ◽  
Heart Dose ◽  
The Mean ◽  
Mean Lung Dose ◽  
Mean Heart Dose

AbstractThis study aims to develop a volume-based algorithm (VBA) that can rapidly optimize rotating gantry arc angles and predict the lung V5 preceding the treatment planning. This phantom study was performed in the dynamic arc therapy planning systems for an esophageal cancer model. The angle of rotation of the gantry around the isocenter as defined as arc angle (θA), ranging from 360° to 80° with an interval of 20°, resulting in 15 different θA of treatment plans. The corresponding predicted lung V5 was calculated by the VBA, the mean lung dose, lung V5, lung V20, mean heart dose, heart V30, the spinal cord maximum dose and conformity index were assessed from dose–volume histogram in the treatment plan. Correlations between the predicted lung V5 and the dosimetric indices were evaluated using Pearson’s correlation coefficient. The results showed that the predicted lung V5 and the lung V5 in the treatment plan were positively correlated (r = 0.996, p < 0.001). As the θA decreased, lung V5, lung V20, and the mean lung dose decreased while the mean heart dose, V30 and the spinal cord maximum dose increased. The V20 and the mean lung dose also showed high correlations with the predicted lung V5 (r = 0.974, 0.999, p < 0.001). This study successfully developed an efficient VBA to rapidly calculate the θA to predict the lung V5 and reduce the lung dose, with potentials to improve the current clinical practice of dynamic arc radiotherapy.

Dosimetric evaluation of organs at risk to toxicities between multicatheter accelerated partial-breast irradiation and whole-breast external beam radiotherapy.

2014 ◽  
Vol 32 (26_suppl) ◽  
pp. 94-94
Author(s):  
Tabitha Y Chan ◽  
Poh Wee Tan ◽  
Chek Wee Tan ◽  
Johann I Tang
Keyword(s):  
External Beam Radiotherapy ◽  
Accelerated Partial Breast Irradiation ◽  
Partial Breast Irradiation ◽  
Lung Dose ◽  
Ipsilateral Lung ◽  
Heart Dose ◽  
Peak Dose ◽  
The Mean ◽  
Mean Lung Dose ◽  
Mean Heart Dose

94 Background: This study aims to quantify the dosimetric reduction to the heart and lung when comparing Whole Breast External Beam Radiotherapy(WBEBRT) with Multicatheter Accelerated Partial Breast Irradiation(MCAPBI) for early stage left sided breast cancer. Methods: Planning CT data sets of 13 patients with left breast cancer receiving multicatheter brachytherapy post breast conserving surgery were used to create two independent treatment plans – WBEBRT prescribed to 50Gy/25fractions and MCAPBI prescribed to 34Gy/10fractions. Dose parameters for (i) heart, (ii) left anterior descending(LAD) artery and (iii) ipsilateral lung were calculated and compared between the two treatment modalities. Results: After adjusting for Equivalent Dose in 2Gy Fractions(EQD2), comparing MCAPBI with WBEBRT, the largest dose reduction was for the LAD artery whose point dose differed by a factor of 4.9. Although somewhat less pronounced, this was also true for the mean lung dose of the ipsilateral lung and mean heart dose with a factor of 3.8 and 2.1 respectively. Compared to WBEBRT, the mean MCAPBI heart D0.1cc (representing the dose received by the most highly exposed 0.1 cc of the risk organ, i.e. the dose peak) was significantly lower(16.43Gy vs 48.82Gy;p<0.01) as well as mean heart dose(MHD) was significantly lower(2.33Gy vs 4.85Gy; p<0.01). Similarly, mean point dose for MCAPBI LAD was significantly lower compared to WBEBRT(9.85Gy vs 47.92Gy; p<0.05). Peak dose and mean lung dose(MLD) for ipsilateral lung was also lower for MCAPBI compared to WBEBRT (Peak dose: 22.19Gy vs 50.45Gy(p<0.05); MLD: 2.31Gy vs 8.73Gy(p<0.05). Conclusions: Compared to WBEBRT, MCAPBI showed a significant reduction in radiation dose for the heart and lung. This may translate into better cardiac and pulmonary toxicities for patients undergoing MCAPBI.

scholarly journals Analysis of cardiac toxicity after definitive chemoradiotherapy for esophageal cancer using a biological dose–volume histogram

2020 ◽  
Vol 61 (2) ◽  
pp. 298-306
Author(s):  
Yuki Takeuchi ◽  
Yuji Murakami ◽  
Tsubasa Kameoka ◽  
Masanori Ochi ◽  
Nobuki Imano ◽  
...  
Keyword(s):  
Risk Factors ◽  
Esophageal Cancer ◽  
Cardiac Toxicity ◽  
Dose Volume Histogram ◽  
Definitive Chemoradiotherapy ◽  
Heart Dose ◽  
Dose Volume ◽  
The Mean ◽  
Mean Heart Dose ◽  
The Relationship

Abstract This study aimed to evaluate the relationship between cardiac toxicity after definitive chemoradiotherapy (CRT) for esophageal cancer and the dose–volume histogram (DVH) of organs at risk (OARs) [using biological effective dose (BED)]. We analyzed the data of 83 patients with esophageal cancer treated using definitive CRT between 2001 and 2016. Furthermore, we evaluated pericardial effusion (PE) as a measure of cardiac toxicity. The median total irradiation dose was 60 (50.4–71) Gy. Symptomatic PE was observed in 12 (14%) patients. The heart and pericardium V5–V100-BED were significantly higher in patients with symptomatic PE than in those without symptomatic PE (heart: V5–V95-BED, P &lt; 0.001; V100-BED, P = 0.0053, and pericardium: V5–V40-BED, V55–V95-BED, P &lt; 0.001; V45–50-BED, V100-BED, P &lt; 0.05, respectively). Receiver operating characteristic curve analysis showed that the dose–volume parameter of the pericardium and the heart that was most strongly associated with an adverse cardiac event was V80-BED, and the mean dose and the cut-off value were 27.38% and 61.7 Gy-BED, respectively. Multivariate analysis showed that the pericardium V80-BED and the mean heart dose-BED were risk factors for symptomatic PE (P &lt; 0.001, respectively). We revealed the relationship between the irradiated dose of the OARs and symptomatic PE using a BED-based dose–volume histogram. Pericardium V80-BED and mean heart dose-BED were the most relevant risk factors for symptomatic PE.

Method of predicting the mean lung dose based on a patient׳s anatomy and dose-volume histograms

2017 ◽  
Vol 42 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Anna Zawadzka ◽  
Marta Nesteruk ◽  
Beata Brzozowska ◽  
Paweł F. Kukołowicz
Keyword(s):  
Lung Dose ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
The Mean ◽  
Mean Lung Dose

Tree-based exploration of the optimization objectives for automatic cervical cancer IMRT treatment planning

2021 ◽  
pp. 20210214
Author(s):  
Hanlin Wang ◽  
Ruoxi Wang ◽  
Jiacheng Liu ◽  
Jian Zhang ◽  
Kaining Yao ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Spinal Cord ◽  
Femoral Head ◽  
Treatment Planning ◽  
Planning Process ◽  
Conformity Index ◽  
Plan Quality ◽  
The Mean ◽  
Automatic Treatment ◽  
Better Than

Objectives: To develop and evaluate a practical automatic treatment planning method for Intensity-Modulated Radiation Therapy (IMRT) in cervical cancer cases. Methods: A novel algorithm named as Optimization Objectives Tree Search Algorithm (OOTSA) was proposed to emulate the planning optimization process and achieve a progressively improving IMRT plan, based on the Eclipse Scripting Application Programming Interface (ESAPI). Thirty previously treated cervical cancer cases were selected from the clinical database and comparison was made between the OOTSA-generated plans and clinical treated plans and RapidPlan-based (RP) plans. Results: In clinical evaluation, compared with plan scores of the clinical plans and the RP plans, 22 and 26 of the OOTSA plans were considered as clinically improved in terms of plan quality, respectively. The average conformity index (CI) for the PTV in the OOTSA plans was 0.86 ± 0.01 (mean ± 1 standard deviation), better than those in the RP plans (0.83 ± 0.02) and the clinical plans (0.71 ± 0.11). Compared with the clinical plans, the mean doses of femoral head, rectum, spinal cord and right kidney in the OOTSA plans were reduced by 2.34 ± 2.87 Gy, 1.67 ± 2.10 Gy, 4.12 ± 6.44 Gy and 1.15 ± 2.67 Gy. Compared with the RP plans, the mean doses of femoral head, spinal cord, right kidney and small intestine in the OOTSA plans were reduced by 3.31 ± 1.55 Gy, 4.25 ± 3.69 Gy, 1.54 ± 2.23 Gy and 3.33 ± 1.91 Gy, respectively. In the OOTSA plans, the mean dose of bladder was slightly increased, with 2.33 ± 2.55 Gy (versus clinical plans) and 1.37 ± 1.74 Gy (versus RP plans). The average elapsed time of OOTSA and clinical planning were 59.2 ± 3.47 min and 76.53 ± 5.19 min. Conclusions: The plans created by OOTSA have been shown marginally better than the manual plans, especially in preserving OARs. In addition, the time of automatic treatment planning has shown a reduction compared to a manual planning process, and the variation of plan quality was greatly reduced. Although improvement on the algorithm is warranted, this proof-of-concept study has demonstrated that the proposed approach can be a practical solution for automatic planning. Advances in knowledge: The proposed method is novel in the emulation strategy of the physicists’ iterative operation during the planning process. Based on the existing optimizers, this method can be a simple yet effective solution for automated IMRT treatment planning.

scholarly journals Dosimetric and radiobiological comparison of treatment plan between CyberKnife and EDGE in stereotactic body radiotherapy for pancreatic cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhi-tao Dai ◽  
Li Ma ◽  
Ting-ting Cao ◽  
Lian Zhu ◽  
Man Zhao ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Spinal Cord ◽  
Stereotactic Body Radiotherapy ◽  
Dose Distribution ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Locally Advanced ◽  
Conformity Index ◽  
Homogeneous Dose

AbstractTo perform a comparison of the different stereotactic body radiotherapy (SBRT) plans between the Varian EDGE and CyberKnife (CK) systems for locally advanced unresectable pancreatic cancer. Fifteen patients with pancreatic cancer were selected in this study. The median planning target volume (PTV) was 28.688 cm3 (5.736–49.246 cm3). The SBRT plans for the EDGE and CK were generated in the Eclipse and Multiplan systems respectively with the same contouring and dose constrains for PTV and organs at risk (OARs). Dose distributions in PTV were evaluated in terms of coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), and gradient index (GI). OARs, including spinal cord, bowel, stomach, duodenum and kidneys were statistically evaluated by different dose-volume metrics and equivalent uniform dose (EUD). The volume covered by the different isodose lines (ISDL) ranging from 10 to 100% for normal tissue were also analyzed. All SBRT plans for EDGE and CK met the dose constraints for PTV and OARs. For the PTV, the dosimetric metrics in EDGE plans were lower than that in CK, except that D99 and GI were slightly higher. The EDGE plans with lower CI, nCI and HI were superior to generate more conformal and homogeneous dose distribution for PTV. For the normal tissue, the CK plans were better at OARs sparing. The radiobiological indices EUD of spinal cord, duodenum, stomach, and kidneys were lower for CK plans, except that liver were higher. The volumes of normal tissue covered by medium ISDLs (with range of 20–70%) were lower for CK plans while that covered by high and low ISDLs were lower for EDGE plans. This study indicated that both EDGE and CK generated equivalent plan quality, and both systems can be considered as beneficial techniques for SBRT of pancreatic cancer. EDGE plans offered more conformal and homogeneous dose distribution for PTV, while the CK plans could minimize the exposure of OARs.

scholarly journals Dose Volume Relationship in Estimating Cardiac Doses in Breast Cancer Radiotherapy

2020 ◽  
Author(s):  
Lucy Pattanayak ◽  
Swodeep Mohanty ◽  
Deepak Kumar Sahu ◽  
Tapas Kumar Dash ◽  
Itishree Priyadarsini
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Conformal Radiotherapy ◽  
Free Breathing ◽  
P Value ◽  
Carcinoma Breast ◽  
Heart Dose ◽  
Cardiac Dose ◽  
The Mean ◽  
Mean Heart Dose

Introduction: Radiation therapy is an integral part of adjuvant treatment for breast cancer which reduces local recurrence and significantly increases survival. But, radiation therapy also has the propensity to increase cardiac morbidity and mortality due to dose received by the heart which is more in left-sided breast cancer. Mean Heart dose and Maximum Heart Distance (MHD) are two parameters to study dose received by the heart. Aim: The purpose of this study was to determine individual doses received by the heart and to correlate MHD with the mean heart dose received by heart in carcinoma breast patients receiving radiotherapy. Materials and Methods: Ninety patients of histologically proven carcinoma breast who attended the Department of Radiotherapy, Acharya Harihar Regional Cancer, Cuttack from January 2017 to January 2019 were selected for a prospective observational study. All patients were treated with 3D Conformal Radiotherapy technique using free breathing multi slice Computed Tomography (CT) scans to contour target and vital organs. Parallel opposed tangential treatment plans were generated for each patient. Individual dose received by the heart and MHD was assessed for each case. SPSS version 21 used for statistical analysis. The Spearman’s Rho test was used for correlation of MHD with Mean heart dose. The Mann-Whitney U test was used for comparing mean of MHD in left-sided and right-sided breast cancer. The Independent t-test was used for comparing means of Mean heart dose in left-sided and right-sided breast cancer. A p-value <0.05 was considered as statistically significant. Results: The Mean Heart Dose was 4.63 Gy for left-sided breast carcinoma patients and 0.846 Gy for right-sided breast cancer and there was a significant difference (p<0.001). Mean MHD for left-sided breast cancer was 2.974 cm while for right-sided it was 0.017 cm, the difference was statistically significant (p-value <0.001). MHD also correlated positively with Mean Heart Dose with correlation coefficient of 0.849 and p-value <0.001. Conclusion: MHD and Mean Heart dose were significantly higher in left-sided breast cancer receiving radiotherapy. MHD was also found to be positively related to Mean Heart dose and therefore found to be an important predictor of cardiac dose. For right-sided breast carcinoma receiving radiotherapy, free breathing technique using 3-Dimensional Conformal Radiotherapy (3DCRT) will suffice in terms of cardiac dose.

PO-1074 Is the mean heart dose the best predictor of cardiac toxicity after Hodgkin Lymphoma irradiation?

2021 ◽  
Vol 161 ◽  
pp. S894
Author(s):  
R. Moujahed ◽  
M. Ben Rejeb ◽  
S. Ghorbel ◽  
A. Hamdoun ◽  
Z. Naimi ◽  
...  
Keyword(s):  
Hodgkin Lymphoma ◽  
Cardiac Toxicity ◽  
Heart Dose ◽  
The Mean ◽  
Mean Heart Dose

Effect of Radiotherapy and Chemotherapy on Pulmonary Function After Treatment for Breast Cancer and Lymphoma: A Follow-Up Study

1999 ◽  
Vol 17 (10) ◽  
pp. 3091-3100 ◽  
Author(s):  
Jacqueline C.M. Theuws ◽  
Sara H. Muller ◽  
Yvette Seppenwoolde ◽  
Stefan L.S. Kwa ◽  
Liesbeth J. Boersma ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Three Dimensional ◽  
Forced Expiratory Volume ◽  
Lung Dose ◽  
Alveolar Volume ◽  
Initial Reduction ◽  
The Mean ◽  
Mean Lung Dose

PURPOSE: To determine the changes in pulmonary function tests (PFTs) 0 to 48 months after treatment for breast cancer and lymphoma. PATIENTS AND METHODS: The alveolar volume (VA), vital capacity, forced expiratory volume in 1 second, and corrected transfer factor of carbon monoxide (TL,COc) were measured in 69 breast cancer and 41 lymphoma patients before treatment and 3, 18, and 48 months after treatment with radiotherapy alone or radiotherapy in combination with chemotherapy (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine; cyclophosphamide, epidoxorubicin, fluorouracil; cyclophosphamide, thiotepa, carboplatin; cyclophosphamide, methotrexate, fluorouracil). The three-dimensional dose distribution in the lung of each patient was converted to the mean lung dose. Statistical analysis was used to evaluate the changes in PFT values over time in relation to age, sex, smoking, chemotherapy, and the mean lung dose. RESULTS: After an initial reduction in PFT values at 3 months, significant recovery was seen at 18 months for all patients. Thereafter, no further improvement could be demonstrated. Reductions in spirometry values and VA were related to the mean lung dose only (0.9% per Gy at 3 months and 0.4% per Gy mean dose at 18 months). TL,COc decreased 1.1% per Gy mean dose and additionally decreased 6% when chemotherapy was given after radiotherapy. Chemotherapy administered before radiotherapy reduced baseline TL,COc values by 8% to 21%. All patients showed an improvement of 5% at 18 months. CONCLUSION: On the basis of the mean lung dose and the chemotherapy regimen, the changes in PFT values can be estimated before treatment within 10% of the values actually observed in 72% to 85% of our patients with healthy lungs.

O114 TUMOR VOLUME REGRESSION DURING NEOADJUVANT CHEMORADIOTHERAPY FOR ESOPHAGEAL CANCER: A PROSPECTIVE STUDY WITH WEEKLY MRI

2019 ◽  
Vol 32 (Supplement_2) ◽  
Author(s):  
Ingmar L Defize ◽  
Mick R Boekhoff ◽  
Alicia S Borggreve ◽  
Noriyoshi Takahashi ◽  
Jelle P Ruurda ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Tumor Volume ◽  
Tumor Regression ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Neoadjuvant Chemoradiotherapy ◽  
Linear Process ◽  
Relative Volume ◽  
Mri Scans ◽  
The Mean

Abstract Aim To assess changes in tumor volume during neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer with weekly MRI. Background & Methods Neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer can cause tumor regression, however data on the magnitude of the volumetric changes during nCRT are scarce. Tumor regression can induce changes in the thoracic anatomy, with smaller target volumes and displacement of organs at risk (OARs) in close proximity to the tumor target as a result. Adaptation of the radiotherapy treatment plan according to volumetric changes during treatment might reduce dose to the OARs while maintaining adequate target coverage. In the current study patients with histologically proven esophageal cancer undergoing nCRT for esophageal cancer underwent 6 MRI scans: 1 scan prior to nCRT and 5 weekly scans during treatment. Tumors were delineated on T2 weighted images by two gastrointestinal radiation oncologists and volumetric changes were assessed. Results A total of 164 MRI scans of 28 patients were included. The mean tumor volume at baseline was 45ml (SD ± 23ml). Tumor volume regression started after the first week of nCRT and appeared to be a linear process with significant declines in tumor volume every subsequent week (p-values <0.05). The mean relative volume regression was 25% (SD ±15) between baseline and the fifth week of treatment (Figure 1.) Conclusion This study shows a significant linear decrease in tumor volume after the first week of nCRT for esophageal cancer on weekly MRI. These findings suggest the possible benefit of radiotherapy plan adaptations during nCRT.

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