SPIE BiOS, 2023 (Optical Methods for Tumor Treatment and Detection) – We introduce a new feature of our Dosie™ modeling software that enables more accurate treatment planning for intracavitary PDT to treat pleural lung cancer. Dosie has been extended to model the light dose that is accumulated on the pleural cavity surface, induced by a moving isotropic light source that is attached to a treatment wand. This work is a collaborative effort with the Perlman School of Medicine at the University of Pennsylvania to build an integrated light delivery and dosimetry platform, PEDSy, for icav-PDT.
Our presentation at Photonics West 2023, BiOS:
Location: Room 307 (South Level Three)
When: 28 January 2023, 11:30 AM - 1:50 AM
We developed a simulation method for modeling the light fluence delivery in intracavity Photodynamic Therapy (icav-PDT) for pleural lung cancer using a moving light source. Due to the large surface area of the pleural lung cavity, the light source needs to be moved to deliver a uniform dose around the entire cavity. While multiple fixed detectors are used for dosimetry at a few locations, an accurate simulation of light fluence and fluence rate is still needed for the rest of the cavity. We extended an existing Monte Carlo (MC) based light propagation solver to support moving light sources by densely sampling the continuous light source trajectory and assigning the proper number of photon packages launched along the way. The performance of Simphotek GPU CUDA-based implementation of the method – PEDSy-MC – has been demonstrated on a life-size lung-shaped phantom, custom printed for testing icav-PDT navigation system at the Perlman School of Medicine (PSM) – calculations completed under a minute (for some cases) and within minutes have been achieved. We demonstrate results within a 5% error of the analytic solution for multiple detectors in the phantom. PEDSy-MC is accompanied by a dose-cavity visualization tool that allows real-time inspection of dose values of the treated cavity in 2D and 3D, which will be expanded to ongoing clinical trials at PSM. PSM has developed a technology to measure 8-detectors in a pleural cavity phantom using Photofrin-mediated PDT that has been used during validation.
Figure: A schematic diagram of light delivery in icav-PDT. A moving point isotropic light source is attached to a wand, which is tracked by PEDSy infrared navigation system which provides the trajectory of the wand. The trajectory is supplied to the new Dosie Monte Carlo light transport module that estimates the light dose accumulated over the cavity.