Proceedings of SPIE--the International Society for Optical Engineering

Our medical research library holds 6 studies published in Proceedings of SPIE--the International Society for Optical Engineering (2012–2023). Each entry links to the study's record on PubMed and, where there is one, to the publisher's page and a free full text. 6 have an abstract, the authors' own summary as PubMed records it: open "Abstract" to read it.

About the journal

• Publisher: SPIE, The International Society for Optical Engineering
• Published: 1981 to the present, United States
• Language: English
• ISSN: 0277-786X (print), 1996-756X (electronic)
• Continues: Proceedings of the Society of Photo-optical Instrumentation Engineers
• Its record in the NLM Catalog

2020s

• A real-time IR navigation system for pleural photodynamic therapy with a 3D surface acquisition system. H. Sun, D. Sourvanos, M. Potasek, et al. 2023;12359. PubMed · Publisher · Free full text

  Abstract

  Photodynamic therapy (PDT) has been used intraoperatively to treat patients with malignant pleural mesothelioma. For the efficiency of PDT, it is crucial to deliver light doses uniformly. The current procedure utilizes eight light detectors placed inside the pleural cavity to monitor the light. An updated navigation system, combined with a novel scanning system, is developed to provide real-time guidance for physicians during pleural PDT to improve light delivery. The scanning system consists of two handheld three-dimensional (3D) scanners to capture the pleural cavity's surface topographies quickly and precisely before PDT so that the target surface can be identified for real-time light fluence distribution calculation during PDT. An algorithm is developed to further process the scanned volume to denoise for accurate light fluence calculation and rotate the local coordinate system into any desired direction for a clear visualization during the real-time guidance. The navigation coordinate system is registered to the patient coordinate system utilizing at least three markers to track the light source point position within the pleural cavity throughout the treatment. During PDT, the light source position, the scanned pleural cavity, and the light fluence distribution for the cavity's surface will be displayed in 3D and 2D, respectively. For validation, this novel system is tested using phantom studies with a large chest phantom and 3D-printed lung phantoms of different volumes based on a personal CT scan, immersed in a liquid tissue-simulating phantom with different optical properties, and treated with eight isotropic detectors and the navigation system.

• PDT Light Fluence Phantom Modeling of the Human Pleural Cavity: A Proof-of-Concept Pre-Clinical Study. D. Sourvanos, H. Sun, K.A. Cengel, et al. 2023;12359. PubMed · Publisher · Free full text

  Abstract

  We have developed a novel scanning protocol for a life-sized human phantom model using handheld three-dimensional (3D) surface acquisition devices. This technology will be utilized to develop light fluence modeling of the internal pleural cavity space during Photodynamic Therapy (PDT) of malignant mesothelioma. The external aspect of the chest cavity phantom was prefabricated of a hardened synthetic polymer resembling ordinary human anatomy (pleural cavity space) and the internal aspect remained hollow without any characterizations. Both surfaces were layered with non-reflective adhesive paper to create non-uniformed surface topographies. These surface characteristics were established in randomized X-Y-Z coordinates ranging in dimensions from 1-15mm. This protocol utilized the handheld Occipital Scanner and the MEDIT i700. The Occipital device required a minimum scanner-to-surface distance of 24cm and the MEDIT device 1cm respectively. The external and internal aspects of the phantom model were successfully scanned acquiring digital measurements in actual value and converted into a digital image file. The initial surface rendering was acquired by the Occipital device and applied with proprietary software to guide the MEDIT device to fill voided areas. This protocol is accompanied by a visualization tool that allows for real-time inspection of surface acquisition in 2D and 3D. This scanning protocol can be utilized to scan the pleural cavity for real-time guidance for light fluence modeling during PDT, which will be expanded to ongoing clinical trials.

2010s

• Deformable medical image registration of pleural cavity for photodynamic therapy by using finite-element based method. R. Penjweini, M.M. Kim, A. Dimofte, et al. 2016;9701:970106. PubMed · Publisher · Free full text

  Abstract

  When the pleural cavity is opened during the surgery portion of pleural photodynamic therapy (PDT) of malignant mesothelioma, the pleural volume will deform. This impacts the delivered dose when using highly conformal treatment techniques. To track the anatomical changes and contour the lung and chest cavity, an infrared camera-based navigation system (NDI) is used during PDT. In the same patient, a series of computed tomography (CT) scans of the lungs are also acquired before the surgery. The reconstructed three-dimensional contours from both NDI and CTs are imported into COMSOL Multiphysics software, where a finite element-based (FEM) deformable image registration is obtained. The CT contour is registered to the corresponding NDI contour by overlapping the center of masses and aligning their orientations. The NDI contour is considered as the reference contour, and the CT contour is used as the target one, which will be deformed. Deformed Geometry model is applied in COMSOL to obtain a deformed target contour. The distortion of the volume at X, Y and Z is mapped to illustrate the transformation of the target contour. The initial assessment shows that FEM-based image deformable registration can fuse images acquired by different modalities. It provides insights into the deformation of anatomical structures along X, Y and Z-axes. The deformed contour has good matches to the reference contour after the dynamic matching process. The resulting three-dimensional deformation map can be used to obtain the locations of other critical anatomic structures, e.g., heart, during surgery.

• Monte Carlo simulation of light fluence calculation during pleural PDT. J.L. Meo, T. Zhu. 2013;8568. PubMed · Publisher · Free full text

  Abstract

  A thorough understanding of light distribution in the desired tissue is necessary for accurate light dosimetry in PDT. Solving the problem of light dose depends, in part, on the geometry of the tissue to be treated. When considering PDT in the thoracic cavity for treatment of malignant, localized tumors such as those observed in malignant pleural mesothelioma (MPM), changes in light dose caused by the cavity geometry should be accounted for in order to improve treatment efficacy. Cavity-like geometries demonstrate what is known as the "integrating sphere effect" where multiple light scattering off the cavity walls induces an overall increase in light dose in the cavity. We present a Monte Carlo simulation of light fluence based on a spherical and an elliptical cavity geometry with various dimensions. The tissue optical properties as well as the non-scattering medium (air and water) varies. We have also introduced small absorption inside the cavity to simulate the effect of blood absorption. We expand the MC simulation to track photons both within the cavity and in the surrounding cavity walls. Simulations are run for a variety of cavity optical properties determined using spectroscopic methods. We concluded from the MC simulation that the light fluence inside the cavity is inversely proportional to the surface area.

• Real-time treatment feedback guidance of Pleural PDT. T.C. Zhu, M.M. Kim, X. Liang, et al. 2013;8568. PubMed · Publisher · Free full text

  Abstract

  Pleural photodynamic therapy (PDT) has been used as an adjuvant treatment with lung-sparing surgical treatment for mesothelioma with remarkable results. In the current intrapleural PDT protocol, a moving fiber-based point source is used to deliver the light and the light dose are monitored by 7 detectors placed in the pleural cavity. To improve the delivery of light dose uniformity, an infrared (IR) camera system is used to track the motion of the light sources. A treatment planning system uses feedback from the detectors as well as the IR camera to update light fluence distribution in real-time, which is used to guide the light source motion for uniform light dose distribution. We have improved the GUI of the light dose calculation engine to provide real-time light fluence distribution suitable for guiding the surgery to delivery light more uniformly. A dual-correction method is used in the feedback system, so that fluence calculation can match detector readings using both direct and scatter light models. An improved measurement device is developed to automatically acquire laser position for the point source. Comparison of the effects of the guidance is presented in phantom study.

• A real-time treatment guidance system for Pleural PDT. T.C. Zhu, X. Liang, J. Sandell, et al. 2012;8210. PubMed · Publisher · Free full text

  Abstract

  Intrapleural photodynamic therapy (PDT) has been used as an adjuvant treatment with lung-sparing surgical treatment for mesothelioma. In the current intrapleural PDT protocol, a moving fiber-based point source is used to deliver the light and the light dose are monitored by 7 detectors placed in the pleural cavity. To improve the delivery of light dose uniformity, an infrared (IR) camera system is used to track the motion of the light sources. A treatment planning system uses feedback from the detectors as well as the IR camera to update light fluence distribution in real-time, which is used to guide the light source motion for uniform light dose distribution. We have reported previously the success of using IR camera to passively monitor the light fluence rate distribution. In this study, the real-time feedback has been implemented in the current system prototype, by transferring data from the IR camera to a computer at a rate of 20 Hz, and by calculation/displaying using Matlab. A dual-correction method is used in the feedback system, so that fluence calculation can match detector readings. Preliminary data from a phantom showed superior light uniformity using this method. Light fluence uniformity from patient treatments is also shown using the correction method dose model.

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