Clinical treatment planning optimization by Powell's method for gamma unit treatment system

Yulong Yan, Huazhong Shu, Xudong Bao, Limin Luo, Yi Bai

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Purpose: This article presents a new optimization method for stereotactic radiosurgery treatment planning for gamma unit treatment system. Methods and Materials: The gamma unit has been utilized in stereotactic radiosurgery for about 30 years, but the usual procedure for a physician- physicist team to design a treatment plan is a trial-and-error approach. Isodose curves are viewed on two-dimensional computed tomography (CT) or magnetic resonance (MR) image planes, which is not only time consuming but also seldom achieves the optimal treatment plan, especially when the isocenter weights are regarded. We developed a treatment-planning system on a computer workstation in which Powell's optimization method is realized. The optimization process starts with the initial parameters (the number of isocenters as well as corresponding 3D isocenters coordinates, collimator sizes, and weight factors) roughly determined by the physician-physicist team. The objective function can be changed to consider protection of sensitive tissues. Results: We use the plan parameters given by a well- trained physician-physicist team, or ones that the author give roughly as the initial parameters for the optimization procedure. Dosimetric results of optimization show a better high dose-volume conformation to the target volume compared to the doctor's plan. Conclusion: This method converges quickly and is not sensitive to the initial parameters. It achieves an excellent conformation of the estimated isodose curves with the contours of the target volume. If the initial parameters are varied, there will be a little difference in parameters' configuration, but the dosimetric results proved almost to be the same.

Original languageEnglish (US)
Pages (from-to)247-254
Number of pages8
JournalInternational Journal of Radiation Oncology Biology Physics
Issue number1
StatePublished - Aug 1 1997


  • 3D treatment planning
  • Nonlinear programming
  • Stereotactic radiosurgery

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research


Dive into the research topics of 'Clinical treatment planning optimization by Powell's method for gamma unit treatment system'. Together they form a unique fingerprint.

Cite this