Target volume uncertainty and a method to visualize its effect on the target dose prescription.

Purpose: To consider the uncertainty in the construction of target boundaries for optimization, and to demonstrate how the principles of mathematical programming can be applied to determine and display the effect on the tumor dose of making small changes to the target boundary.

Methods: The effect on the achievable target dose of making successive small shifts to the target boundary within its range of uncertainty was found by constructing a mixed-integer linear program that automated the placement of the beam angles using the initial target volume.

Results: The method was demonstrated using contours taken from a nasopharynx case, with dose limits placed on surrounding structures.

Early-stage endometrial cancer: is intravaginal radiation therapy alone sufficient therapy?

For half a century, adjuvant radiation therapy has been an important component in the treatment of patients with early-stage endometrial cancer believed to be at significant risk of local or regional recurrence. The widespread adoption of up-front surgical treatment and staging, including nodal assessment, has raised new questions about the need for and extent of postoperative adjuvant treatment. Furthermore, in some institutions, even in the absence of complete surgical staging, the extent of postoperative adjuvant treatment is being reassessed.