scholarly journals A comparative dosemetric study of bilateral breast cancer after modified radical mastectomy with HT and VMAT

2021 ◽  
Author(s):  
Xuhong Liu ◽  
Yaoxiong Xia ◽  
Li Chang ◽  
Xiao Chen
Keyword(s):  
Breast Cancer ◽  
Spinal Cord ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Bilateral Breast Cancer ◽  
Radical Mastectomy ◽  
Target Volume ◽  
Conformity Index ◽  
Modified Radical Mastectomy ◽  
Synchronous Bilateral Breast Cancer

Abstract Background: The purpose of this study was to compare the dosimetric differences in helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) plans of bilateral breast cancer after modified radical mastectomy.Methods: Ten patients with synchronous bilateral breast cancer (SBBC) who received modified radical mastectomy were selected for study. Two radiotherapy treatment plans, including HT and VMAT, were created for each patient. The prescribed doses of bilateral breast cancer and dual target volumes were given 25 times at 50Gy. The dosemetric parameters of planning target volume (PTV) and organs at risk (OARs) between HT and VMAT plans were compared and evaluated. Results: For PTV, HT had a higher V95 than that of VMAT plans (99.23 ± 0.61 % vs 98.17± 1.08 %, p=0.024). The conformity index (CI) between two techniques was statistically equivalent (0.812 ± 0.03 vs 0.793 ± 0.04, p=0.322) and the homogeneity index (HI) was reduced from 0.127 to 0.105 (p=0.007) when compared with that of VMAT. For OARs, HT had significantly lower Dmax for spinal cord and V5 for heart when compared with those of VMAT plans (16.68 Gy and 20.93% vs 38.82 Gy and 30.26%, respectively) (p<0.001). HT plans showed significantly lower V5, V10 and V20, that resulted in lower Dmean for the lungs (13.38 Gy vs 14.28Gy, p=0.013). However, VMAT showed specific advantages on V10, V20 and V30 for the heart and V5 and V10 for the liver when compared with those of HT plans (p<0.01). The Dmean for the heart and liver between the two techniques was not significantly different (p>0.05). HT plans also showed greater monitor units (MUs) and beam on time. Conclusion: HT had better PTV coverage and HI and showed better protections for the spinal cord and lungs compared with those of VMAT plans. HT plans effectively reduced the low-dose volume (V5) of the heart, while VMAT plans reduced V10, V20 and V30 for the heart. Both HT and VMAT plans exhibited similar Dmean for the heart and liver. The treatment efficiency of VMAT is higher than that of HT plans, and therefore, physicians need to choose a reasonable radiotherapy plan according to patient's conditions.

scholarly journals Quantitative and dosimetric analysis for treating synchronous bilateral breast cancer using two radiotherapy planning techniques

2021 ◽  
Vol 27 (3) ◽  
pp. 201-206
Author(s):  
Özlem Mermut ◽  
Aysun Ozsoy Ata ◽  
Didem Can Trabulus
Keyword(s):  
Breast Cancer ◽  
Early Stage ◽  
Organs At Risk ◽  
Bilateral Breast Cancer ◽  
Radiotherapy Planning ◽  
Conformity Index ◽  
Treatment Unit ◽  
Significant Difference ◽  
Synchronous Bilateral Breast Cancer ◽  
The Right

Abstract Objective: We compared mono-isocenter and dual-isocenter plans in synchronous bilateral breast cancer (SBBC), which is defined as tumours occurring simultaneously in both breasts, and evaluated the effects of these differences in plans on organs-at-risk (OARs). Materials and methods: We evaluated 10 women with early stage, nod negative (Tis-2N0M0) SBBC. The treatment dose was determined to be 50 Gy. We used mean dose and VXGy to evaluate the OARs. To evaluate the effectiveness of treatment plans, Homogeneity index (HI), conformity index (CI) and sigma index (SI) and monitor units (MU) of monoisocenter (MIT) and dual-isocenter (DIT) plans were compared. During bilateral breast planning, for the single-centre plan, the isocenter was placed at the center of both breasts at a depth of 3-4 cm. For the two-center plan, dual-isocenters were placed on the right and left breasts. Results: No significant difference between the techniques in terms of the scope of the target volume was observed. Statistically significant results were not achieved in MIT and DIT plans for OARs. Upon comparing MIT and DIT, the right-side monitor unit (MU) value in DIT (p = 0.011) was statistically significantly lower than that in MIT. Upon comparing right-left side MIT and DIT, the MU value (p = 0.028) was significantly lower in DIT than MIT. Conclusion: SBBC irradiation is more complex than unilateral breast radiotherapy. No significant difference between both techniques and OARs was observed. However, we recommend MIT as a priority technique due to the ability to protect OARs, ease of administration during treatment, and the fact that the patient stays in the treatment unit for a shorter period of time.

scholarly journals Dosimetric Comparison of Three Radiotherapy Techniques in Irradiation of Left-Sided Breast Cancer Patients after Radical Mastectomy

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jian Hu ◽  
Guang Han ◽  
Yu Lei ◽  
Ximing Xu ◽  
Wei Ge ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Radical Mastectomy ◽  
Target Volume ◽  
Conformity Index ◽  
Breast Cancer Patients ◽  
Ipsilateral Lung ◽  
Significant Difference

Introduction. This study is aimed at evaluating the dosimetric differences among target segmented planning (TSP), conventional 9-field intensity modulated radiation therapy (9FIMRT) planning, and volumetric modulated arc therapy (VMAT) planning for postmastectomy radiotherapy of left-sided breast cancer patients. Material and Methods. Fifteen left-sided breast cancer patients who underwent radical mastectomy were enrolled. In TSP, the planning target volume (PTV) was divided into four regions (supra/infraclavicular, chest wall, external mammary region, and internal mammary region), and each individual PTV region was treated with respective fixed fields. Results. The VMAT plans showed superior to PTV dose conformity index (CI), homogeneity index (HI), protection of the ipsilateral lung, monitor units (MUs), and maximum dose (Dmax) to the contralateral breast compared with TSP and 9FIMRT plans. The TSP provided better protection for Dmean of the heart and left ventricle (p<0.05). A dose for left anterior descending artery from the three techniques had no significant difference. Compared with the 9FIMRT plans, the V5Gy (%) and V10Gy (%) for the ipsilateral lung were significantly reduced with TSP and VMAT (p<0.05). The V5Gy (%) and V10Gy (%) for the ipsilateral lung turned out to be similar between VMAT and TSP techniques. Conclusions. Our study indicates that VMAT should be a better choice of radiotherapy for left-sided breast cancer patients after radical mastectomy. If VMAT is unavailable, 9FIMRT can achieve better CI and HI values and be more MU-efficient compared with TSP; however, TSP can effectively reduce the low dose volume of the ipsilateral lungs and heart.

scholarly journals Hybrid volumetric-modulated arc therapy for postoperative breast cancer including regional lymph nodes: the advantage of dosimetric data and safety of toxicities

2020 ◽  
Vol 61 (5) ◽  
pp. 747-754
Author(s):  
Yoshiko Doi ◽  
Minoru Nakao ◽  
Hideharu Miura ◽  
Shuichi Ozawa ◽  
Masahiro Kenjo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Lymph Nodes ◽  
Irradiation Dose ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Conformity Index ◽  
Regional Lymph Nodes ◽  
Dosimetric Data ◽  
Arc Therapy

ABSTRACT To improve the homogeneity and conformity of the irradiation dose for postoperative breast cancer including regional lymph nodes, we planned Hybrid volumetric-modulated arc therapy (VMAT), which combines conventional tangential field mainly for the chest area and VMAT mainly for the supraclavicular area and marginal zone. In this study, we compared the dosimetric impact between traditional 3D conformal radiotherapy (3DCRT) and Hybrid VMAT and observed toxicities following Hybrid VMAT. A total of 70 patients indicated between October 2016 and December 2017 were included. The prescribed dose was 50 Gy/25 fractions. For the dosimetric impact, 3DCRT and Hybrid VMAT plans were compared in each patient with respect to the dosimetric parameters. Toxicities were followed using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up duration was 319 days. For the dosimetric impact, the homogeneity index (HI) and conformity index (CI) of PTV were significantly improved in the Hybrid VMAT plan compared with that in the 3DCRT plan (HI, 0.15 ± 0.07 in Hybrid VMAT vs 0.41 ± 0.19 in 3DCRT, P &lt; 0.001; CI, 1.61 ± 0.44 in Hybrid VMAT vs 2.10 ± 0.56 in 3DCRT, P &lt; 0.001). The mean irradiated ipsilateral lung dose was not significantly different in both plans (12.0 ± 2.4 Gy in Hybrid VMAT vs 11.8 ± 2.8 Gy in 3DCRT, P &lt; 0.533). Regarding toxicity, there were no patients who developed ≥grade 3 acute toxicity and ≥grade 2 pneumonitis during the follow-up. Hybrid VMAT for postoperative breast cancer including regional lymph nodes was a reasonable technique that improved the homogeneity and conformity of the irradiation dose to the planning target volume while keeping the irradiation dose to organs at risk to a minimum.

scholarly journals Non-coplanar volumetric modulated arc therapy for locoregional radiotherapy of left-sided breast cancer including internal mammary nodes

2021 ◽  
Vol 55 (4) ◽  
pp. 499-507
Author(s):  
Yuan Xu ◽  
Pan Ma ◽  
Zhihui Hu ◽  
Yuan Tian ◽  
Kuo Men ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Coronary Artery ◽  
Volumetric Modulated Arc Therapy ◽  
Left Lung ◽  
Target Volume ◽  
Conformity Index ◽  
Internal Mammary Nodes ◽  
Arc Therapy ◽  
Internal Mammary ◽  
The Mean

Abstract Background Non-coplanar volumetric modulated arc therapy (ncVMAT) is proposed to reduce toxicity in heart and lungs for locoregional radiotherapy of left-sided breast cancer, including internal mammary nodes (IMN). Patients and methods This retrospective study included 10 patients with left-sided breast cancer who underwent locoregional radiotherapy after breast-conserving surgery. For each patient, the ncVMAT plan was designed with four partial arcs comprising two coplanar arcs and two non-coplanar arcs, with a couch rotating to 90°. The prescribed dose was normalized to cover 95% of planning target volume (PTV), with 50 Gy delivered in 25 fractions. For each ncVMAT plan, dosimetric parameters were compared with the coplanar volumetric modulated arc therapy (coV-MAT) plan. Results T here were improvements in conformity index, homogeneity index and V55 of total target volume (PTVall) comparing ncVMAT to coVMAT (p < 0.001). Among the organs at risk, the average V30, V20, V10, V5, and mean dose (Dmean) of the heart decreased significantly (p < 0.001). Furthermore, ncVMAT significantly reduced the mean V20, V10, V5, and Dmean of left lung and the mean V10 and V5 and Dmean of contralateral lung (p < 0.001). An improved sparing of the left anterior descending coronary artery and right breast were also observed with ncVMAT (p < 0.001). Conclusions Compared to coVMAT, ncVMAT provides improved conformity and homogeneity of whole P TV, better dose sparing of the heart, bilateral lungs, left anterior descending coronary artery (LAD), and right breast for locoregional radiotherapy of left-sided breast cancer with IMN, potentially reducing the risk of normal tissue damage.

Volumetric modulated arc therapy: a dosimetric comparison with dynamic IMRT and step-and-shoot IMRT

2019 ◽  
Vol 19 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Payal Raina ◽  
Sudha Singh ◽  
Rajanigandha Tudu ◽  
Rashmi Singh ◽  
Anup Kumar
Keyword(s):  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Delivery Time ◽  
Arc Therapy ◽  
Step And Shoot

AbstractAim:The aim of this study was to compare volumetric modulated arc therapy (VMAT) with dynamic intensity-modulated radiation therapy (dIMRT) and step-and-shoot IMRT (ssIMRT) for different treatment sites.Materials and methods:Twelve patients were selected for the planning comparison study. This included three head and neck, three brain, three rectal and three cervical cancer patients. Total dose of 50 Gy was given for all the plans. Plans were done for Elekta synergy with Monaco treatment planning system. All plans were generated with 6 MV photons beam. Plan evaluation was based on the ability to meet the dose volume histogram, dose homogeneity index, conformity index and radiation delivery time, and monitor unit needs to deliver the prescribed dose.Results:The VMAT and dIMRT plans achieved the better conformity (CI98% = 0·965 ± 0·023) and (CI98% = 0·939 ± 0·01), respectively, while ssIMRT plans were slightly inferior (CI98% = 0·901 ± 0·038). The inhomogeneity in the planning target volume (PTV) was highest with ssIMRT with HI equal to 0·097 ± 0·015 when compared to VMAT with HI equal to 0·092 ± 0·0369 and 0·095 ± 0·023 with dIMRT. The integral dose is found to be inferior with VMAT 105·31 ± 53·6 (Gy L) when compared with dIMRT 110·75 ± 52·9 (Gy L) and ssIMRT 115 38 ± 55·1(Gy L). All the techniques respected the planning objective for all organs at risk. The delivery time per fraction for VMAT was much lower than dIMRT and ssIMRT.Findings:Our results indicate that dIMRT and VMAT provide better sparing of normal tissue, homogeneity and conformity than ssIMRT with reduced treatment delivery time.

scholarly journals Deep Learning-Aided Automatic Contouring of Clinical Target Volumes for Radiotherapy in Breast Cancer After Modified Radical Mastectomy

2022 ◽  
Vol 9 ◽  
Author(s):  
Jinqiang You ◽  
Qingxin Wang ◽  
Ruoxi Wang ◽  
Qin An ◽  
Jing Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Data Augmentation ◽  
Radical Mastectomy ◽  
Qualitative Evaluation ◽  
Breast Conserving Surgery ◽  
Target Volume ◽  
Superior Performance ◽  
Dice Similarity Coefficient ◽  
Modified Radical Mastectomy ◽  
Automatic Contouring

Purpose: The aim of this study is to develop a practicable automatic clinical target volume (CTV) delineation method for radiotherapy of breast cancer after modified radical mastectomy.Methods: Unlike breast conserving surgery, the radiotherapy CTV for modified radical mastectomy involves several regions, including CTV in the chest wall (CTVcw), supra- and infra-clavicular region (CTVsc), and internal mammary lymphatic region (CTVim). For accurate and efficient segmentation of the CTVs in radiotherapy of breast cancer after modified radical mastectomy, a multi-scale convolutional neural network with an orientation attention mechanism is proposed to capture the corresponding features in different perception fields. A channel-specific local Dice loss, alongside several data augmentation methods, is also designed specifically to stabilize the model training and improve the generalization performance of the model. The segmentation performance is quantitatively evaluated by statistical metrics and qualitatively evaluated by clinicians in terms of consistency and time efficiency.Results: The proposed method is trained and evaluated on the self-collected dataset, which contains 110 computed tomography scans from patients with breast cancer who underwent modified mastectomy. The experimental results show that the proposed segmentation method achieved superior performance in terms of Dice similarity coefficient (DSC), Hausdorff distance (HD) and Average symmetric surface distance (ASSD) compared with baseline approaches.Conclusion: Both quantitative and qualitative evaluation results demonstrated that the specifically designed method is practical and effective in automatic contouring of CTVs for radiotherapy of breast cancer after modified radical mastectomy. Clinicians can significantly save time on manual delineation while obtaining contouring results with high consistency by employing this method.

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