The dosimetric comparison between tomotherapy and RapidArc in normal tissue sparing for nasopharyngeal carcinoma

2019 ◽  
Vol 19 (3) ◽  
pp. 237-241
Author(s):  
Pubade Kaewpruk ◽  
Somvilai Chakrabandhu ◽  
Somsak Wanwilairat ◽  
Wannapha Nobnop
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Parotid Gland ◽  
Treatment Planning ◽  
Normal Tissue ◽  
Planning System ◽  
Delivery Time ◽  
Target Dose ◽  
Normal Tissue Sparing ◽  
Tissue Sparing ◽  
Left Parotid Gland

AbstractPurpose:To compare the dosimetric results regarding the sparing effect on normal tissue between RapidArc (RA) and helical tomotherapy (HT) plans for nasopharyngeal carcinoma (NPC) patients in cases of the equal target dose controls utilising two techniques.Materials and Methods:Thirteen NPC patients treated with HT were replanned using the Varian Eclipse treatment planning system (TPS) for the RA plan. The target dose of the RA plan was optimised equally to the HT plan in terms of target coverage, dose conformity (CI) and dose homogeneity (HI) for assessing the normal tissue sparing between two techniques. All dose–volume parameters monitor units (MUs) and delivery time were also investigated.Results:All dosimetric parameter comparisons of organs-at-risk (OARs) between the RA and HT plans were not significantly different for brain stem, spinal cord and cochlea. However, the RA plan showed a significantly lower dose to the left parotid gland. The mean and median dose were significantly lower in the RA plan versus the HT plan by p-value 0·005 and 0·039, respectively. The MUs and delivery time were also significantly lower in the RA plan with a p-value of 0·00.Conclusions:With the same planning target volume coverage, homogeneity and conformity, almost all of RA and HT treatment planning met the planning goal for normal tissue sparing. There were no significant differences between the two techniques except in the left parotid gland. The RA plans were superior to HT plans by effectively reducing the MUs and treatment time.

Knowledge-based planning for stereotactic body radiation therapy (SBRT) of the liver.

2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 375-375 ◽  
Author(s):  
Hunter C Gits ◽  
Janell Dow ◽  
Martha Matuszak ◽  
Mary Uan-Sian Feng
Keyword(s):  
Normal Tissue ◽  
Planning System ◽  
Treatment Planning System ◽  
Target Coverage ◽  
High Quality ◽  
Normal Tissue Sparing ◽  
Knowledge Based ◽  
Knowledge Based Planning ◽  
Liver Sbrt ◽  
Tissue Sparing

375 Background: SBRT is emerging as a treatment option for patients with unresectable liver tumors. However, generating high quality liver SBRT plans is technically challenging and user-dependent. Aiming for high tumor doses and low normal tissue doses can demand lengthy planning times and result in plans of inconsistent quality. This study investigates knowledge-based planning (KBP) as a standardized method to ensure efficacy, safety, and efficiency for SBRT plans and allow for broader use of this therapy. Methods: SBRT treatment plans were manually optimized for 55 liver cancer cases by an expert liver dosimetrist in a commercial treatment planning system (Varian Eclipse v13.6). Each volumetric modulated arc therapy plan was approved by a physician using strict criteria for target coverage and normal tissue sparing. The plans were used to create a custom model in a KBP system (RapidPlan, Varian Eclipse v13.6) designed to improve both efficiency and standardization of quality. To validate the model, 15 new cases were optimized manually by an expert liver dosimetrist and then semi-automatically using the KBP model. The validation plans were compared based on target coverage, normal tissue sparing, and planning time. Results: Compared to manual plans created by an expert liver dosimetrist, KBP-generated plans showed similar target coverage and improved normal tissue sparing with similar planning times. Mean and minimum target doses were similar, as was D98, p > 0.2 for all. Normal tissue complication probability for liver damage was marginally lower with KBP, mean 3 vs. 1%, p = 0.07. Doses to adjacent organs including stomach, heart, and bowel were similar. Manual planning required a median and mean time of 15 and 20 minutes, respectively, range 8-55 min. KBP required similar times of 12 and 19 min, range 8-50 min. 9 of 15 KBP cases were automated, while 6 plans required dosimetrist improvement. Conclusions: Using KBP, high quality plans for liver SBRT can be created automatically or semi-automatically. These plans are comparable to those generated by an expert liver dosimetrist. KBP could be used to standardize treatments between institutions, particularly when experience with liver SBRT is limited.

SU-F-T-186: A Treatment Planning Study of Normal Tissue Sparing with Robustness Optimized IMPT, 4Pi IMRT, and VMAT for Head and Neck Cases

2016 ◽  
Vol 43 (6Part15) ◽  
pp. 3504-3504
Author(s):  
J Zhang ◽  
D Nguyen ◽  
K Woods ◽  
A Tran ◽  
X Li ◽  
...  
Keyword(s):  
Head And Neck ◽  
Treatment Planning ◽  
Normal Tissue ◽  
Planning Study ◽  
Normal Tissue Sparing ◽  
Tissue Sparing

scholarly journals The normal tissue sparing obtained with simultaneous treatment of pelvic lymph nodes and bladder using intensity-modulated radiotherapy

2009 ◽  
Vol 48 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Jimmi Søndergaard ◽  
Morten Høyer ◽  
Jørgen B. Petersen ◽  
Pauliina Wright ◽  
Cai Grau ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Normal Tissue ◽  
Intensity Modulated Radiotherapy ◽  
Simultaneous Treatment ◽  
Pelvic Lymph Nodes ◽  
Intensity Modulated ◽  
Normal Tissue Sparing ◽  
Tissue Sparing

scholarly journals Treatment planning comparison of volumetric modulated arc therapy with Trilogy and Halcyon for bilateral breast cancer

2021 ◽  
Author(s):  
Tao Sun ◽  
Xiutong Lin ◽  
Guifang Zhang ◽  
Qingtao Qiu ◽  
Chengqiang Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Treatment Planning ◽  
Volumetric Modulated Arc Therapy ◽  
Bilateral Breast Cancer ◽  
Planning System ◽  
Skin Dose ◽  
Delivery Time ◽  
Dose Volume ◽  
Arc Therapy ◽  
The Mean

Abstract Background: The Halcyon is a new machine from the Varian company. The purpose of this study was to evaluate the dosimetry of the Halcyon in treatment of bilateral breast cancer with volumetric modulated arc therapy. Methods: On CT images of 10 patients with bilateral breast cancer, four Halcyon plans with different setup fields were generated, and dosimetric comparisons using Bonferroni’s multiple comparisons test were conducted among the four plans. Whole and partial arc plans on the Trilogy and the Halcyon, referred to as T-4arc, T-8arc, H-4arc and H-8arc, were designed. The prescription dose was 50 Gy in 2-Gy fractions. All plans were designed with the Eclipse version 15.5 treatment planning system. The dosimetric differences between whole and partial arc plans in the same accelerator were compared using the Mann-Whitney U test. The better Halcyon plan was selected for the further dosimetric comparison of the plan quality and delivery efficiency between the Trilogy and the Halcyon. Results:Halcyon plans with high‐quality megavoltage cone beam CT setup fields increased the Dmean, D2 and V107 of the planning target volume (PTV) and the V5 and Dmean of the heart, left ventricle (LV) and lungs compared with other Halcyon setup plans. The mean dose and low dose volume of the heart, lungs and liver were significantly decreased in T-8arc plans compared to T-4arc plans. In terms of the V5, V20, V30, V40 and Dmean of the heart, the V20, V30, V40 and Dmean of the LV, the V30, V40, Dmax and Dmean of the left anterior descending artery (LAD), and the V5 and V40 of lungs, H-8arc was significantly higher than H-4arc (p<0.05). Compared with the Trilogy’s plans, the Halcyon’s plans reduced the high-dose volume of the heart and LV but increased the mean dose of the heart. For the dose of the LAD and the V20 and V30 of lungs, there was no significant difference between the two accelerators. Compared with the Trilogy, plans on the Halcyon significantly increased the skin dose but also significantly reduced the delivery time. Conclusion: For the Halcyon, the whole-arc plans have more dosimetric advantages than partial-arc plans in bilateral breast cancer radiotherapy. Although the mean dose of the heart and the skin dose are increased, the doses of the cardiac substructure and other OARs are comparable to the Trilogy, and the delivery time is significantly reduced.

scholarly journals Normal tissue sparing using different techniques for prostate irradiation

2020 ◽  
Vol 25 (1) ◽  
pp. 85-90
Author(s):  
Barbara Melles-Bencsik ◽  
Tamás Pócza ◽  
Tibor Major ◽  
Péter Ágoston ◽  
Kliton Jorgo ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Normal Tissue Sparing ◽  
Tissue Sparing
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