A simple and reliable index for scoring rival stereotactic radiosurgery plans

Area of Science:

• Medical Physics
• Radiation Oncology
• Neurosurgery

Background:

• Stereotactic radiosurgery requires robust methods for evaluating treatment plan quality.
• Comparing multiple radiosurgery plans necessitates objective and efficient scoring systems.

Purpose of the Study:

• To introduce a simple and reliable index for ranking competing stereotactic radiosurgery plans.
• To provide a tool that assists in the evaluation and optimization of radiosurgery treatment plans.

Main Methods:

• The Conformity/Gradient Index (CGI) was developed as an average of conformity and gradient scores.
• CGI calculation requires three key data points: total volume at prescription dose, target volume, and total volume at half prescription dose.
• The index is a straightforward function of these three volumetric parameters.

Main Results:

• Ranking multiple stereotactic radiosurgery plans using the CGI closely correlated with rankings based on biologic indices.
• The CGI demonstrated strong agreement with nontarget brain normal tissue complication probabilities.
• This suggests the CGI is a valid surrogate for complex biologic evaluations.

Conclusions:

• The CGI serves as a simple and rapid tool for evaluating radiosurgery plans.
• It assists radiation oncologists in selecting and optimizing among various treatment plan options.
• The index facilitates efficient decision-making in stereotactic radiosurgery planning.