An empirical method for automatic determination of maximum number of segments in DMPO-based IMRT for Head and Neck cases

Ranganathan, Vaitheeswaran; Das, K.J. Maria

doi:10.1016/j.rpor.2016.09.004

Cited by 4 publications

(2 citation statements)

References 17 publications

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“…The gantry degrees of the plans were 180°, 135°, 90°, 40°, 230°, 275°, and 320°. Using the DMPO optimization algorithm [8] to realize the intensity adjustment and inverse optimization. Different minimum segmentation area (MSA) parameters were used as an optimization parameter which are 4 cm 2 , 9 cm 2 , 14 cm 2 , 20 cm 2 , 25 cm 2 , 40 cm 2 , 50 cm 2 , 60 cm 2 , 80 cm 2 , and 100 cm 2 .…”

Section: Methodsmentioning

confidence: 99%

A study of different minimum segment area parameters on automatic IMRT plans for cervical cancer using Pinnacle3 9.10 TPS

Sun

Wang

et al. 2022

Medicine

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Based on Pinnacle 3 9.10 treatment planning system (TPS) automatic planning module, we investigated the effect of minimum segmentation area (MSA) parameters on Auto-Plan Intensity Modulated Radiotherapy (AP-IMRT) without affecting the dose distribution of the target and the Organ at Risk (OAR). The results provided the basis for the ideal MSA parameters in the design of AP-IMRT plan. Ten patients with cervical cancer in our hospital were selected randomly for AP-IMRT design. Each patient was devised with 10 AP-IMRT plans. The prescription dose of PTV was 50 Gy/25 fractions. The radiotherapy plans of all patients were adopted with 7 field-averaged fixed fields. The MSA was set to 4 cm 2 , 9 cm 2 , 14 cm 2 , 20 cm 2 , 25 cm 2 , 40 cm 2 , 50 cm 2 , 60 cm 2 , 80 cm 2 , and 100 cm 2 . Plan quality and delivery efficiency were evaluated based on dose-volume histograms (DVHs), control points, monitor units (MUs), dosimetric measurement verification results, and plan delivery time. Except for the small difference in monitor units, the number of segmentations and target dose coverage, there were no statistically significant differences between the other dosimetric parameters in the planning target volumes. With the increase of MSA, the total number of MUs in AP-IMRT decreased from (649 ± 32) MUs to (312 ± 26) MUs, and the total number of segmentations decreased from (69 ± 1) to (28 ± 3). There was no statistical significance in the dose distribution of AP-IMRT target area with the MSA of 4-50 cm 2 (P > .05). There was no significant difference in OAR dose between AP-IMRT plans with different MSA (P > .05). The calculated gamma indices using the 3% /3 mm and 2%/2 mm criteria. Both of the gamma pass rate and DTA pass rate all ≥95% under the condition of MSA are greater than 4 cm 2 , and the difference was no statistically significant (P > .05). The plan delivery times decreased with increasing MSA (P < .05). When using Pinnacle 3 9.10 TPS to design AP-IMRT plan for cervical cancer, the parameter of MSA can be increased appropriately. Increasing the MSA allows for improved plan delivery accuracy and efficiency without significantly affecting the AP-IMRT plan quality. The MSA in the range of 14 to 50 cm 2 can obtain a more reasonable dose distribution in the target area while the dose of target area and OAR had no significant changes. It is important to improve the plan quality, delivery accuracy, and efficiency for cervical AP-IMRT radiation therapy.

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Section: Methodsmentioning

confidence: 99%

A study of different minimum segment area parameters on automatic IMRT plans for cervical cancer using Pinnacle3 9.10 TPS

Sun

Wang

et al. 2022

Medicine

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“…There are several studies which indicate that a lesser number of control points are adequate to create an acceptable plan quality and control points with smaller MUs might affect the plan deliverability and increase the treatment delivery time. (Huang et al, 2016;Ranganathan et al, 2016). On the other hand, when the tumor is located at the center of the patient body and surrounded by many OARS, beam modulation may be required in the whole 360 Deg angle.…”

Section: Introductionmentioning

confidence: 99%

A Novel Method for Improving VMAT Plan Quality and Deliverability

Ramar

Meher

2022

Asian Pac J Cancer Prev

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Background: A new VMAT method called "Augmented Arc" (or simply Aug Arc) is proposed. The aim of this study is to demonstrate the validity of the proposed method in different clinical cases. Basically, Aug Arc refers to the portion(s) of the VMAT arc that is augmented with an additional arc to improve the plan quality. The Aug Arc portions in the Arc is determined using an objective function-based scoring method called "ψ -score". Methods: To validate our approach, we have applied it in four clinical cases: Lung, Abdomen, Gynecologic (Gyn) and Pancreas. Basically, for Lung and Pancreas cases, four sets of plans were created, which are: (1) Single arc plan (S Arc), (2) Double arc plan (D Arc), (3) Partial Arc plan without Aug Arc (P Arc) and (4) Partial plan with Aug Arc (P+Aug Arc). For Abdomen and Gyn cases, three sets of plans were created, which are: (1) Single arc plan (S Arc), (2) Double arc plan (D Arc) and(3) Single Arc with Aug Arc (S+Aug Arc). To compute the "ψ -score", an initial optimization was performed by using full Arc with 4-degree gantry spacing. Subsequently, Aug Arc portions were identified using the ψ -score plot in the single arc and partial arc scenarios. Results: The study finds that the proposed method is useful to improve the plan quality and plan deliverability for both centrically and non-centrically located tumors in terms of reducing the OAR dose, monitor units, beam on time and low dose volume without compromising the target coverage. Conclusion: The results indicate that the proposed approach could strike a balance between full double arc and single arc or partial arc in such a way that the planner can find a sweet spot of delivery parameters that result in optimal plan quality.

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Objective function based ranking method for selection of optimal beam angles in IMRT

et al. 2020

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An empirical method for automatic determination of maximum number of segments in DMPO-based IMRT for Head and Neck cases

Cited by 4 publications

References 17 publications

A study of different minimum segment area parameters on automatic IMRT plans for cervical cancer using Pinnacle3 9.10 TPS

A study of different minimum segment area parameters on automatic IMRT plans for cervical cancer using Pinnacle3 9.10 TPS

A Novel Method for Improving VMAT Plan Quality and Deliverability

Objective function based ranking method for selection of optimal beam angles in IMRT

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