Optimizing computerized treatment planning for the gamma knife by source culling

Luo, Limin; Hu, Shu; Yu, Wenxue; Yan, Yulong; Bao, Xudong; Fu, Yao

doi:10.1016/s0360-3016(99)00341-7

“…Other researchers have designed Gamma Knife treatments with various optimization schemes [5,13,14,15,16,18,19,20,21]. Several investigators model the problem as a geometric problem, where optimum shots fall along a skeletonization of the lesion [1,2,18].…”

Section: Introductionmentioning

confidence: 99%

The Relationship Between the Number of Shots and the Quality of Gamma Knife Radiosurgeries

Cheek

¹

,

Holder

²

,

Fuß

³

et al. 2005

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. (2005). The relationship between the number of shots and the quality of gamma knife radiosurgeries. Optimization and Engineering, 6, 449-462. doi: 10.1007/s11081-005-2067-1 The Relationship Between Abstract Radiosurgery is a non-invasive alternative to brain surgery that uses a single focused application of high radiation to destroy intracerebral target tissues. A Gamma Knife delivers such treatments by using 201 cylindrically collimated cobalt-60 sources that are arranged in a hemispherical pattern and aimed to a common focal point. The accumulation of radiation at the focal point, called a "shot" due to the spherical nature of the dose distribution, is used to ablate (or destroy) target tissue in the brain. If the target is small and spherical, it is easily treated by choosing one of four available collimators (4, 8, 14, or 18 mm). For large, irregular targets, multiple shots are typically required to treat the entire lesion, and the process of determining the optimal arrangement and number of shots is complex.In this research, fast simulated annealing and a novel objective function are used to investigate the relationship between the number of shots and the quality of the resulting treatment. Sets of 5, 10, 25, 50, and an unrestricted number of shots are studied for an arteriovenous malformation (AVM). As the shot limit increases the following improvements in plan quality are observed: the conformity of the prescription isodose line increases, the lesion dose becomes more homogeneous, and an increase use of smaller collimators to deposit dose. Large improvements in plan quality are realized by increasing the number of shots from 5 to 50, and to achieve a similar magnitude of improvement past 50 requires an increase over 1500 shots for the complex lesion investigated. This observation suggests that it is clinically valuable to improve the Gamma Knife's delivery capabilities so that 50 shot treatments are possible.

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“…[6][7][8][9][10][11][12] One approach incorporates the assumption that each shot of radiation can be modeled as a rigid sphere. The problem is then reduced to one of geometric coverage, and a ball packing approach can be used to determine the shot locations and sizes.…”

Section: Introductionmentioning

confidence: 99%

“…6, 12 The use of a modified Powell's method in conjunction with simulated annealing has also been proposed. [8][9][10][11] This paper addresses a different approach where the dose distribution is modeled and a formal constrained optimization is used to determine the treatment plan. With this technique, the shot sizes, locations, and weights are optimized simultaneously.…”

Section: Introductionmentioning

confidence: 99%

Inverse Treatment Planning for Gamma Knife Radiosurgery

Shepard¹,

Ferris²,

Mal³

et al. 2000

The Use of Computers in Radiation Therapy

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An inverse treatment planning system for Gamma Knife radiosurgery has been developed using nonlinear programming techniques. The system optimizes the shot sizes, locations, and weights for Gamma Knife treatments. In the patient's prescription, the user can specify both the maximum number of shots of radiation and a minimum isodose line that must surround the entire treatment volume. After satisfying all of the constraints included in the prescription, the system maximizes the conformity of the dose distribution. This automated approach to treatment planning has been applied retrospectively to a series of patient cases, and each optimized plan has been compared to the corresponding manual plan produced by an experienced user. The results demonstrate that this tool can often improve the tumor dose homogeneity while using fewer shots than were included in the original plan. Therefore, inverse treatment planning should improve both the quality and the efficiency of Gamma Knife treatments.

show abstract

“…[8][9][10][11] This paper addresses a different approach where the dose distribution is modeled and a formal constrained optimization is used to determine the treatment plan. With this technique, the shot sizes, locations, and weights are optimized simultaneously.…”

Section: Introductionmentioning

confidence: 99%

Inverse treatment planning for Gamma Knife radiosurgery

Shepard

¹

,

Ferris

²

,

Ove

³

et al. 2000

View full text Add to dashboard Cite

An inverse treatment planning system for Gamma Knife radiosurgery has been developed using nonlinear programming techniques. The system optimizes the shot sizes, locations, and weights for Gamma Knife treatments. In the patient's prescription, the user can specify both the maximum number of shots of radiation and a minimum isodose line that must surround the entire treatment volume. After satisfying all of the constraints included in the prescription, the system maximizes the conformity of the dose distribution. This automated approach to treatment planning has been applied retrospectively to a series of patient cases, and each optimized plan has been compared to the corresponding manual plan produced by an experienced user. The results demonstrate that this tool can often improve the tumor dose homogeneity while using fewer shots than were included in the original plan. Therefore, inverse treatment planning should improve both the quality and the efficiency of Gamma Knife treatments.

show abstract

Optimizing computerized treatment planning for the gamma knife by source culling

Cited by 22 publications

References 15 publications

The Relationship Between the Number of Shots and the Quality of Gamma Knife Radiosurgeries

The Relationship Between the Number of Shots and the Quality of Gamma Knife Radiosurgeries

Inverse Treatment Planning for Gamma Knife Radiosurgery

Inverse treatment planning for Gamma Knife radiosurgery

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