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 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.

scholarly journals Plan Quality Comparisons Between 3D-CRT, IMRT, and VMAT Based on 4D-CT for Gastric MALT Lymphoma

2021 ◽  
Vol 41 (8) ◽  
pp. 3941-3947
Author(s):  
TADASHI MATSUMOTO ◽  
RYO TOYA ◽  
YOSHINOBU SHIMOHIGASHI ◽  
TAKAHIRO WATAKABE ◽  
TOMOHIKO MATSUYAMA ◽  
...  
Keyword(s):  
Malt Lymphoma ◽  
Gastric Malt Lymphoma ◽  
Plan Quality ◽  
4D Ct ◽  
3D Crt

Dosimetric comparison between three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in the treatment of different stages of nasopharyngeal carcinoma

2018 ◽  
Vol 18 (1) ◽  
pp. 46-51
Author(s):  
Mohamed S. Ibrahim ◽  
Ehab M. Attalla ◽  
Mostafa El Naggar ◽  
Wael M. Elshemey
Keyword(s):  
Developing Countries ◽  
Nasopharyngeal Carcinoma ◽  
Three Dimensional ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Planning Techniques ◽  
Intensity Modulated ◽  
Three Dimensional Conformal Radiotherapy ◽  
Better Than ◽  
3D Crt

AbstractBackgroundThis work aims to compare the dosimetric performance of three-dimensional conformal radiotherapy (3D-CRT), a relatively available technique in developing countries, to intensity-modulated radiotherapy (IMRT) in the treatment of different stages of nasopharyngeal carcinoma (NPC).Materials and MethodsAccording to the diagnostic stages, 40 NPC patients were divided into two equal groups. Three planning techniques such as 3D-CRT, seven-field IMRT (7F-IMRT) and nine-field IMRT (9F-IMRT) were compared. Dose prescriptions of 70 and 66 Gy were delivered in 35 fractions to gross planning target volume (PTV1) and bilateral retropharyngeal carcinoma (PTV2), respectively.ResultsStage I dose data for almost all of the three investigated planning techniques obey the international recommendations. The dose delivered to PTV1 and PTV2 for 3D-CRT and 7F-IMRT are statistically similar, whereas 9F-IMRT is significantly better than 3D-CRT. For organs at risk (OARs), the delivered dose is significantly better for 9F-IMRT compared with the other two techniques, whereas 7F-IMRT is significantly better than 3D-CRT.Conclusions3D-CRT is an acceptable alternative treatment technique for stage I NPC patients in developing countries suffering from the lack of advanced radiotherapy treatment techniques. 3D-CRT and 7F-IMRT have comparable performance in PTVs, while 9F-IMRT is superior in PTVs and OARs.

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.

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