AbstractID: 8493 Title: Dose Volume Projections
The Dose Volume Projection (DVP) is a new, efficient method of identifying cold spots
in target tissues and hot spots in normal tissues. DVPs are proposed to supplement
current methods of dose presentation and analysis. The method is a variant of ray traced
volume rendering in which doses along rays inside structures are back projected (with or
without divergence) to structure surfaces. For target structures, minimum doses are back
projected showing cold regions. For normal structures, maximum doses are back
projected showing hot regions. We demonstrate the use of DVPs in the context of an
intensity modulated radiotherapy (IMRT) plan, and show how DVPs can supplement
dose volume histograms (DVHs). The method easily identifies the existence and general
location of small cold spots in targets, which might be missed by only inspecting DVHs
or isocurves and isosurfaces. As with other dose data reduction schemes, such as DVHs,
spatial information is reduced and is traded for rapid access to dose information. The
major advantage of DVPs over DVHs is that they offer more spatial information,
concentrate on the most significant aspects of dose distributions, and highlight small, yet
potentially important, dose heterogeneities. DVPs provide less spatial information than
isocurves and isosurfaces, but they are straightforward to interpret, and may speed and
direct the clinician’s interactions with the planning system during a multi-slice dose
review. The dose volume projection is also proposed for treatment plan record keeping.
Partially supported by NCI grant CA85181 (JOD) and Computerized Medical Systems,
Inc.