Composite radiation dose representation using Fuzzy Set theory

Abstract

Composite plans created from different image sets are generated through Deformable Image Registration (DIR) and present a challenge in accurately presenting uncertainties, which vary with anatomy. Our effort focuses on the application of Fuzzy Set theory to provide an accurate dose representation of such a composite treatment plan. The accuracy of the DIR is generally verified through geometrical visual checks, including the confirmation of the corresponding anatomies with edge features, such as bone or organ boundaries. However, the remaining volume of the image (mostly soft tissues) has few significant image features and therefore greater uncertainty. We fuzzified the deformation vector and derived a Fuzzy composite dose. The fuzzification was implemented using Gaussian functions based on the varying uncertainties in the DIR. After establishing the theoretical basis for this new approach, we present two-and three-dimensional examples as proof-of-concept. Using Fuzzy Set theory, composite dose plans displaying localitybased uncertainties were successfully created, providing information previously unavailable to clinicians. Previous to Fuzzy Set dose presentations, clinicians had no measure of confidence in the accuracy of a composite dose plan. Using fuzzified composite dose presentations, clinicians can determine a safe additional dose to previously treated anatomy. This will possibly increase the treatment success rate and reduce the rate of complications.

Quantitative Analysis Tools and Digital Phantoms for Deformable Image Registration Quality Assurance

“…Furthermore, the success and failures of these registrations can be delineated by locality. Park et al 56 investigated a fuzzy composite dose representation to deal with the uncertainty in DIR. It can generate composite dose plans displaying localitybased uncertainties.…”

Estimation of distance error by fuzzy set theory required for strength determination of HDR 192 Ir brachytherapy sources

“…Fuzzy set theory has been applied for risk analysis[ 23 ] and image analysis[ 24 ] in the domain of medical dosimetry. In view of these applications, we have proposed an approach of applying this fuzzy set theory in the quantification of uncertainty associated with the distance error required for the measurement of strength of HDR 192 Ir brachytherapy sources.…”