Aperture generation based on threshold segmentation for intensity modulated radiotherapy treatment planning.

PURPOSE: To reduce computation and decrease planning time with little or no loss in plan quality compared to the column-generation-based (cg) method, a simple method of aperture generation based on threshold segmentation (agts) is proposed.

METHODS: The proposed agts strategy consists of two steps. First, a fuzzy controller is used for noise cancellation; then, new apertures are added using the threshold segmentation algorithm. We tested the proposed method on seven prostate tumor cases using the computational environment for radiotherapy research algorithms for the dose calculations and compared the results with those obtained by generating the plan aperture using the cg method. Specifically, the homogeneity index and conformity number of the planning target volume, organs at risk (OARs) sparing, and total planning time were compared among the two methods.

RESULTS: The proposed agts technique produced treatment plans approximating the cg solution. Furthermore, the planning time required by the agts method was approximately 58.61% ± 0.40 less than that required by the cg method.

CONCLUSIONS: The agts algorithm can decrease planning time with little or no loss in plan quality compared to the cg method.