scholarly journals A Dosimetric Analysis of Reduction Cardiac Dose with Lead Shielding in Breast Cancer Radiotherapy

2021 ◽  
Vol 11 (20) ◽  
pp. 9686
Author(s):  
Hsiao-Wen Chiu ◽  
Lu-Han Lai ◽  
Chien-Yi Ting
Keyword(s):  
Heart Diseases ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Left Breast ◽  
Conformity Index ◽  
Target Area ◽  
Heart Dose ◽  
Breast Cancer Radiotherapy ◽  
3D Crt

Adjuvant radiotherapy is an important treatment modality after breast-conserving surgery. Due to its proximity, radiation therapy for the left breast can often lead to an escalated heart dose that can result in heart diseases. The purpose of this study was to evaluate the heart dose reduction by using lead shields surrounding the left breast. The doses of a 3D conformal radiotherapy (3D-CRT) plan, an intensity-modulated radiotherapy (IMRT) plan, and volumetric-modulated arc therapy (VMAT) to the left breast tumor in a CIRS ATOM anthropomorphic female adult phantom were measured by optically stimulated luminescence dosimeters (OSLDs). To protect critical organs, the skin around the target area was covered by lead shields of two different thicknesses (0.125 mm and 0.25 mm). The results showed that compared to IMRT and 3D-CRT, VMAT provided better planning target volume (PTV) coverage, a better conformity index (CI), and homogeneity index (HI). With the use of lead shields, the thyroid dose was reduced by 5.12–27.5% and 20.51–30%, respectively; the heart dose was reduced by 49.41–50.12% and 56.38–57.42%, respectively; and the lung dose was reduced by 1.23–45.22% and 0.98–57.83%, respectively. Although the clinical application of lead shields was rare, this study verified that it could effectively decrease the heart dose from 4.31 ± 0.09 Gy to 1.88–2.18 Gy, thereby potentially reducing the risk of associated heart diseases by 14.8%. Further works to implement this method into clinical practice are needed.

scholarly journals A COMPARATIVE DOSIMETRIC STUDY OF LEFT SIDED BREAST CANCER AFTER BREAST CONSERVING SURGERY WITH 3D-CRT AND VMAT

2020 ◽  
Vol 8 (11) ◽  
pp. 1088-1093
Author(s):  
F. Kouhen ◽  
◽  
H.El Gouache ◽  
M. Bensediq ◽  
K. Saadi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Volumetric Modulated Arc Therapy ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Breast Conserving Surgery ◽  
Left Breast ◽  
Conformity Index ◽  
Clinical Value ◽  
Three Dimensional Conformal Radiotherapy ◽  
3D Crt

Purpose: This paper aims to compare dosimetric differences based between three-dimensional conformal radiotherapy (3D-CRT), and volumetric modulated arc therapy(VMAT) techniques of radiotherapy plans for postoperative left breast cancer after breast conserving surgery. Materials and Methods: Nineteen patients with left breast cancer who had received breast conserving surgery without nodal involvement. Two separate treatment plans with an identical isocenter were created to each patient: 3D radiotherapy plan with 2 tangent isocentric beams with field-in-field technique andVMAT plan with Two duplicate sets of partial arcs. Results: The VMAT plan showed superior to PTV dose conformity index (CI), homogeneity index (HI), protection of the ipsilateral lung, and heart compared with 3D plan. However, it increases significantly dose to the contralateral breast with D mean which were 0.1±0.003 Gy and 5.31±1.04 Gy, respectively. Conclusion: VMAT greatly decreases the radiation doses delivered to the OAR with maintained therapeutic efficacy.However, further studies evaluating the clinical outcome of treatments are needed to proof the clinical value of this radiation technique.

Radiation-induced biological changes of neural structures in the base of the skull tumours

2017 ◽  
Vol 16 (2) ◽  
pp. 183-198
Author(s):  
C. Gh. Buzea ◽  
C. Mirestean ◽  
Irina Butuc ◽  
A. Zara ◽  
D. T. Iancu
Keyword(s):  
Normal Tissue ◽  
Volumetric Modulated Arc Therapy ◽  
Nasopharyngeal Cancer ◽  
Conformal Radiotherapy ◽  
Planning System ◽  
Conformity Index ◽  
Delivery Times ◽  
Brain Radionecrosis ◽  
The Mean ◽  
3D Crt

AbstractBackground and purposeThe aim of this paper is to compare neural induced changes in three-dimensional conformal radiotherapy (3D-CRT) versus intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) for nasopharyngeal cancers.Materials and methodsRadiotherapy plans for 10 patients with nasopharyngeal cancer stages III and IV were prospectively developed for 3D-CRT, IMRT and VMAT using Varian Eclipse planning system. The same radiation therapist carried out all planning and the same clinical dosimetric constraints were used. Normal tissue complication probabilities were calculated.ResultsThe mean planning target volume’s (PTVs) conformity index (CI) for 3D-CRT was 1·424, for IMRT 1·1, and for VMAT 1·081. The PTV homogeneity (HI) index was 0·204 for 3D-CRT, 0·124 for IMRT and 0·153 for VMAT. Normal tissue complication probabilities gave complex results for 3D-CRT, IMRT and VMAT and are analysed in detail in this paper. The mean monitor units were 95 (range 9–180) for 3D-CRT; 165 (range 52–277) for IMRT; and 331 (range 167–494) for VMAT (p<0·05).ConclusionsVMAT is associated with similar dosimetric advantages as IMRT over 3D-CRT for nasopharyngeal cancer. VMAT is associated with faster delivery times and greater number of mean monitor units than IMRT. Brain radionecrosis severity and risk, in the past, have been underestimated. By improving the life expectancy of patients with nasopharyngeal cancer to ensure maintenance of the neural structures, recommended dose limits should be considered as a first degree priority (as the spinal cord, brainstem, etc.) when IMRT and VMAT plans are implemented.

scholarly journals Dosimetric Comparison of Intensity-Modulated Radiotherapy, Volumetric Modulated Arc Therapy and Hybrid Three-Dimensional Conformal Radiotherapy/Intensity-Modulated Radiotherapy Techniques for Right Breast Cancer

2020 ◽  
Vol 9 (12) ◽  
pp. 3884
Author(s):  
Yi-Chi Liu ◽  
Hung-Ming Chang ◽  
Hsin-Hon Lin ◽  
Chia-Chun Lu ◽  
Lu-Han Lai
Keyword(s):  
Volumetric Modulated Arc Therapy ◽  
Three Dimensional ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Whole Body ◽  
Intensity Modulated ◽  
Arc Therapy ◽  
Effective Doses ◽  
Three Dimensional Conformal Radiotherapy ◽  
3D Crt

This study aimed to compare different types of right breast cancer radiotherapy planning techniques and to estimate the whole-body effective doses and the critical organ absorbed doses. The three planning techniques are intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT; two methods) and hybrid 3D-CRT/IMRT (three-dimensional conformal radiotherapy/intensity-modulated radiotherapy). The VMAT technique includes two methods to deliver a dose: non-continuous partial arc and continuous partial arc. A thermoluminescent dosimeter (TLD) is placed in the RANDO phantom to estimate the organ absorbed dose. Each planning technique applies 50.4 Gy prescription dose and treats critical organs, including the lung and heart. Dose-volume histogram was used to show the planning target volume (V95%), homogeneity index (HI), conformity index (CI), and other optimized indices. The estimation of whole-body effective dose was based on the International Commission on Radiation Protection (ICRP) Publication 60 and 103. The results were as follows: Continuous partial arc and non-continuous partial arc showed the best CI and HI. The heart absorbed doses in the continuous partial arc and hybrid 3D-CRT/IMRT were 0.07 ± 0.01% and 0% (V5% and V10%, respectively). The mean dose of the heart was lowest in hybrid 3D-CRT/IMRT (1.47 Gy ± 0.02). The dose in the left contralateral lung (V5%) was lowest in continuous partial arc (0%). The right ipsilateral lung average dose and V20% are lowest in continuous partial arc. Hybrid 3D-CRT/IMRT has the lowest mean dose to contralateral breast (organs at risk). The whole-body effective doses for ICRP-60 and ICRP-103 were highest in continuous partial arc (2.01 Sv ± 0.23 and 2.89 Sv ± 0.15, respectively). In conclusion, the use of VMAT with continuous arc has a lower risk of radiation pneumonia, while hybrid 3D-CRT/IMRT attain lower secondary malignancy risk and cardiovascular complications.

Dosimetric comparison of 3-dimensional conformal radiotherapy (3D-CRT) and volumetric-modulated arc therapy (VMAT) in locally advanced cancer cervix

2020 ◽  
pp. 1-8
Author(s):  
Animesh Agrawal ◽  
Rahat Hadi ◽  
Satyajeet Rath ◽  
Avinav Bharati ◽  
Madhup Rastogi ◽  
...  
Keyword(s):  
De Novo ◽  
Abdominal Cavity ◽  
Locally Advanced ◽  
Volumetric Modulated Arc Therapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Conformity Index ◽  
Dosimetric Comparison ◽  
Arc Therapy ◽  
3D Crt

Abstract Introduction: Dosimetric advantages of volumetric-modulated arc therapy (VMAT) over three-dimensional conformal radiotherapy (3D-CRT) are not established in a head-on comparison of a uniform group of locally advanced carcinoma of the cervix (LACC). Therefore, we conducted a dosimetric comparison of these two techniques in LACC patients. Materials and methods: Computed tomography (CT) data of histologically proven de novo LACC, including Stage IIB–IIIB and earlier stages deemed inoperable, were included in this prospective observational dosimetric study. Planning was initially done by 3D-CRT technique (dose of 45–50·4 Gy @ 1·8–2 Gy/# was used in the actual treatment), followed by VMAT planning and appropriate dosimetric comparisons were done in 39 cases. Results: For planning target volume coverage, D95, D98 and D100 (p < 0·0001 for all parameters) and V95 and V100 (p = 0·002 and <0·0001, respectively) were significantly improved with VMAT. The conformity index (CI) was significantly better with VMAT (p = 0·03), while 3D-CRT had a significantly better homogeneity index (HI)(p = 0·003). Dose to the urinary bladder was significantly reduced with VMAT compared to 3D-CRT for V20–V50, except V10. The doses to the rectum and abdominal cavity were significantly reduced with VMAT compared to 3D-CRT plans for all parameters (V10–V50). The number of organs at risks (OARs) for which constraints were met was higher with VMAT plans than with 3D-CRT plans, with at least four out of the five OARs protected in 46·1 versus 5·1% and all constraints achieved in 15·4% versus none. Conclusion: We conclude that in dosimetric terms, VMAT is superior to 3D-CRT for LACC.

scholarly journals The Dosimetric Advantages of Robust Optimization Combined With Flatten Filter Free Mode in Left Breast Cancer

2020 ◽  
Author(s):  
Hongying Luo ◽  
Guoping Shan ◽  
Kainan Shao ◽  
Yiwei Yang ◽  
Xia Zhou ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Robust Optimization ◽  
Chest Wall ◽  
Intensity Modulated Radiotherapy ◽  
Left Breast ◽  
Respiratory Movement ◽  
Planning System ◽  
Target Area ◽  
Breast Cancer Radiotherapy ◽  
Significant Difference

Abstract Background and purposesTo explore the advantages of Robust optimization in dosimetry under flatten filter free(FFF) Mode after left breast cancer surgery.Materials and methods21 patients with left breast cancer after surgery were randomly selected from 2019 to 2020. The planned target volume (PTV) dose was prescribed 50Gy /25times and B. With or without Robust optimization were designed on the RayStation planning system with Volume rotary intensity-modulated radiotherapy technology based on the FFF Mode. By moving the center point of the field to simulated the movement of target area of the internal chest wall (0.50cm) caused by Respiratory movement, dosimetry characteristics. Using spss 23.0 to analyse the datum.Resultswhen the chest wall target moved outward, the PTV target area D98, D95, D2, CI and HI with Robust optimization were better than those without Robust, and the coverage rate of PTV-CHESTV50 was significantly higher than that without Robust optimization (P=0.000060), which was 15.39% higher than that without Robust optimization. CTVV50 coverage with Robust optimization was higher than that without Robust optimization, with an increase of 14.48%. In terms of endangering organ parameters, the average spinal cord dose of the plan with Robust optimization was 13.19% lower than that of the plan without Robust optimization, and the lung V5 of the plan without Robust optimization was slightly lower than that of the plan with Robust optimization, which was 1.80% lower than that of the plan without Robust optimization. There was no significant difference in machine execution efficiency between the two groups (P > 0.05).ConclusionsThe Robust optimization could be adopted in the development of postoperative left breast cancer radiotherapy plan, which ensures that the target dose coverage and the dose limit of organ-at-risk still meet the clinical requirements under condition of chest wall displacement caused by respiratory movement.

scholarly journals So sánh các thông số liều lượng của kỹ thuật vmat và 3d-crt trong xạ trị ung thư vú trái và hạch vùng

2020 ◽  
Author(s):  
Đình Long Nguyễn
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Volumetric Modulated Arc Therapy ◽  
Left Lung ◽  
Conformal Radiotherapy ◽  
Left Breast ◽  
Three Dimension ◽  
Breast Cancer Patients ◽  
Arc Therapy ◽  
3D Crt

COMPARISON OF DOSIMETRIC PARAMETERS OF VOLUMETRIC MODULATED ARC THERAPY AND THREE-DIMENSIONAL CONFORMAL RADIOTHERAPY FOR LEFT SIDE BREAST AND REGIONAL NODES Objective: Comparative study of dose parameters of Volumetric modulated arc therapy (VMAT) and three-dimension radiotherapy (3D-CRT) in patients after left breast surgery with radiation therapy with regional lymph nodes. Materials and Methods: Twenty-four plans of 12 left-breast cancer patients were treated with VMAT with 4 partial arc and 3D-CRT plans were added to compare each other, from 1/2018 to 3/2019 at the Vinmec TimesCity International Hospital. Results: The average coverage dose to the treatment volume (PTV) of VMAT plans is better than the 3D-CRT plan (99.10 ± 0.17 % compared to 98.7 ± 0.34 %; p = 0.01). Conformity index (CI), homogeneity index (HI) for VMAT plans also better results CI: 0.99 vs. 0.98; p = 0.26 and HI: 0.096 compared to 0.119; p = 0.02). Organs at risk, at low doses V5Gy, V10Gy VMAT plans do not avoid good doses by 3D-CRT plans: V5Gy for left lung (78.8 ± 4.6 % compared to 55.37 ± 4.38 %) and heart (77.15 ± 9.52 % compared to 19.15 ± 7.93 %) (p <0.001). However, at high doses, 3D-CRT plans are much higher than VMAT: Dose to left lung V20Gy (36.22 ± 3.9 % compared to 22.62 ± 2.43 %), V30Gy (30.6 ± 5.97 % compared to 11.77 ± 2.53 %) and V40Gy (24.73 ± 8.59 % compared to 3.63 ± 2.02 %) (P <0.001). Similarly, the cardiac arrival dose of the 3D-CRT plan is higher than that of VMAT: V20Gy (11.54 ± 5.83 % compared to 9.49 ± 6.00 %, p> 0.05), V30Gy (9.25 ± 5.56 % compared to 2.13 ± 1.89 %) and V40 Gy (7.54 ± 5.03 % compared with 0.2 ± 0.25 %). Dose to coronary arteries also decreased significantly for VMAT plans compared to 3D-CRT: V20Gy (0.8 ± 1.01 % compared to 27.29 ± 15.19 %) V30Gy (0.00 % compared to 23.09 ± 10.73 %). Conclusion: VMAT is dosimetrically superior to the 3D-CRT for left‑sided breast cancer patients with regional nodes by dose coverage to PTV and good ability to avoid heart and lung and coronary arteries than. Key words: Breast cancer, Postmastectomy radiotherapy, Three-dimension conformal radiotherapy, Volumetric modulated arc therapy.

scholarly journals Plan Quality Comparisons Between Three-dimensional Conformal Radiotherapy, Intensity-modulated Radiotherapy, and Volumetric Modulated Arc Therapy Based on Four-dimensional Computed Tomography for Gastric Mucosa-associated Lymphoid Tissue Lymphoma: a Planning Study

2021 ◽  
Author(s):  
Tadashi Matsumoto ◽  
Ryo Toya ◽  
Yoshinobu Shimohigashi ◽  
Takahiro Watakabe ◽  
Tomohiko Matsuyama ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Malt Lymphoma ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Gastric Malt Lymphoma ◽  
Imrt Plan ◽  
Plan Quality ◽  
Better Than ◽  
3D Crt

Abstract Background: Previous planning studies in radiotherapy (RT) for gastric mucosa-associated lymphoid tissue (MALT) lymphoma have been based on three-dimensional computed tomography (3D-CT) images, which do not contain information on the respiratory motion of the stomach. Therefore, we compared the plan quality between 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT) for gastric MALT lymphoma using four-dimensional computed tomography (4D-CT).Methods: Three different treatment plans of four-field 3D-CRT, seven-field IMRT, and double arc VMAT were created based on 4D-CT images of seven patients with gastric MALT lymphoma. An RT dose of 30 Gy was prescribed to the planning target volume (PTV) in 20 fractions. We calculated the minimum dose coverage for 95% of the PTV (D95), homogeneity index (HI), and conformity index (CI) of the PTV, and organs at risk (OARs) doses for the liver, kidneys, spinal cord, and small bowel. Plan quality metric (PQM) scores were also calculated for a comprehensive and objective assessment.Results: There was no significant difference among the three plans in D95 of PTV. HI of PTV for the IMRT plan was significantly better than that of the VMAT (p = 0.047) and 3D-CRT (p = 0.047) plans. HI of PTV for the VMAT plan was significantly better than that of the 3D-CRT plan (p = 0.047). CIs of PTV for the IMRT and VMAT plans were significantly better than that of the 3D-CRT plan (p = 0.047 and p = 0.047, respectively). Dmean of the liver for 3D-CRT was significantly higher than that for the IMRT (p = 0.047) and VMAT (p = 0.047) plans. The PQM scores of the VMAT and IMRT plans were significantly higher than that of the 3D-CRT plan (p = 0.047 and p = 0.047, respectively). The PQM score of the IMRT plan was significantly higher than that of the VMAT plan (p = 0.047).Conclusions: The IMRT plan yields the best plan quality for gastric MALT lymphoma. In terms of plan quality, as opposed to the 3D-CRT plan, we recommend the IMRT and VMAT plans.

scholarly journals Deep-inspirational breath-hold (DIBH) technique in left-sided breast cancer: various aspects of clinical utility

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Szilvia Gaál ◽  
Zsuzsanna Kahán ◽  
Viktor Paczona ◽  
Renáta Kószó ◽  
Rita Drencsényi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Side Effects ◽  
Clinical Utility ◽  
Prospective Trial ◽  
Conformal Radiotherapy ◽  
Free Breathing ◽  
Left Breast ◽  
Breath Hold ◽  
Ipsilateral Lung ◽  
Breast Cancer Radiotherapy

Abstract Background Studying the clinical utility of deep-inspirational breath-hold (DIBH) in left breast cancer radiotherapy (RT) was aimed at focusing on dosimetry and feasibility aspects. Methods In this prospective trial all enrolled patients went through planning CT in supine position under both DIBH and free breathing (FB); in whole breast irradiation (WBI) cases prone CT was also taken. In 3-dimensional conformal radiotherapy (3DCRT) plans heart, left anterior descending coronary artery (LAD), ipsilateral lung and contralateral breast doses were analyzed. The acceptance of DIBH technique as reported by the patients and the staff was analyzed; post-RT side-effects including radiation lung changes (visual scores and lung density measurements) were collected. Results Among 130 enrolled patients 26 were not suitable for the technique while in 16, heart or LAD dose constraints were not met in the DIBH plans. Among 54 and 34 patients receiving WBI and postmastectomy/nodal RT, respectively with DIBH, mean heart dose (MHD) was reduced to < 50%, the heart V25 Gy to < 20%, the LAD mean dose to < 40% and the LAD maximum dose to about 50% as compared to that under FB; the magnitude of benefit was related to the relative increase of the ipsilateral lung volume at DIBH. Nevertheless, heart and LAD dose differences (DIBH vs. FB) individually varied. Among the WBI cases at least one heart/LAD dose parameter was more favorable in the prone or in the supine FB plan in 15 and 4 cases, respectively; differences were numerically small. All DIBH patients completed the RT, inter-fraction repositioning accuracy and radiation side-effects were similar to that of other breast RT techniques. Both the patients and radiographers were satisfied with the technique. Conclusions DIBH is an excellent heart sparing technique in breast RT, but about one-third of the patients do not benefit from that otherwise laborious procedure or benefit less than from an alternative method. Trial registration: retrospectively registered under ISRCTN14360721 (February 12, 2021)

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