An empirical method for splitting arcs in VMAT

Perumal, Bojarajan; Etti, S.; Ranganathan, Vaitheeswaran; Ramar, Natarajan; Kumar, Prajwal; Anto, Gipson Joe; Sureka, C.S.

doi:10.1016/j.ejmp.2021.07.024

Cited by 1 publication

(2 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to that Homogeneity index (HI) and Conformity index (CI) were calculated for all the cases using the below mentioned formulas. 39 HI = D5/D95, where D5 is dose to 5% of volume of target and D95 is dose to 95% of volume of target (Perumal et al, 2021;Stanley et al, 2011). CI (RTOG) = V (RI)/TV (PTV) Where V (RI)is the volume encompassed by prescribed dose (in this case 95% isodose line) and TV (PTV) = Planned Target Volume.…”

Section: Methodsmentioning

confidence: 99%

“…Since ψ -score helps locate the portions of the arc in which the DOF is higher, the peaks in ψ -score will indicate the arc portions wherein TDD is relatively higher. (Ramar et al, 2020;Ranganathan et al, 2018;Ranganathan et al, 2020;Perumal et al, 2021). Hence, it is possible to use ψ -score to identify the arc portions suitable for the proposed Aug Arc.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Novel Method for Improving VMAT Plan Quality and Deliverability

Ramar

Meher

2022

Asian Pac J Cancer Prev

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Methodsmentioning

confidence: 99%