Abstract
Finding a high-quality treatment plan is an essential, yet difficult, stage of Photodynamic therapy (PDT) as it will determine the therapeutic efficacy in eradicating malignant tumors. A high-quality plan is patient-specific, and provides clinicians with the number of fiber-based spherical diffusers, their powers, and their interstitial locations to deliver the required light dose to destroy the tumor while minimizing the damage to surrounding healthy tissues. In this work, we propose a general convex light source power allocation algorithm that, given light source locations, guarantees optimality of the resulting solution in minimizing the over/under-dosage of volumes of interest. Furthermore, we provide an efficient framework for source selection with concomitant power reallocation to achieve treatment plans with a clinically feasible number of sources and comparable quality. We demonstrate our algorithms on virtual test cases that model glioblastoma multiforme tumors, and evaluate the performance of four different photosensitizers with different activation wavelengths and specific tissue uptake ratios. Results show an average reduction of the damage to organs-at-risk (OAR) by 29% to 31% with comparable runtime to existing power allocation techniques.
Highlights
Introduction and prior workPhotodynamic therapy (PDT) is the light activation of photosensitizers, inducing the production of oxygen radicals with the aim to destroy particular tissues in situ
It is worth noting that our proposed cost function in Eq (2) is closely linked to the Dose volume histogram (DVH), since the cost is weighted by the volume of each element and depends only on the dose received at each element and the target dose parameters set for that element
Minimizing the volume-weighted positive difference between the actual received dose and the maximum threshold dose effectively translates to minimizing the area below the DVH curve for an OAR, and maximizing the negative difference between the actual received dose and the minimum threshold dose effectively maximizes the area under the DVH curve for the tumor
Summary
Photodynamic therapy (PDT) is the light activation of photosensitizers, inducing the production of oxygen radicals with the aim to destroy particular tissues in situ. A more efficient illumination scheme that can target deep tissues is interstitial light delivery, in which fiber-based spherical light diffusers are placed directly into the target tissues [4]. Several pre-clinical studies have shown that the treatment response with interstitial delivery is strongly dependent on the light dose distribution, which is itself dependent on the optical properties of the patient’s tissues and the placement of the light sources [5,6,7]. The success and efficacy of interstitial photodynamic therapy (iPDT) strongly depends on planning the photon source placement based on a patient’s particular anatomy of the target and the surrounding tissues
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
