Publications by authors named "Ken Kang-Hsin Wang"
Bioluminescence tomography (BLT) improves upon commonly-used 2D bioluminescence imaging by reconstructing 3D distributions of bioluminescence activity within biological tissue, allowing tumor localization and volume estimation-critical for cancer therapy development. Conventional model-based BLT is computationally challenging due to the ill-posed nature of the problem and data noise. We introduce a self-supervised hybrid neural network (SHyNN) that integrates the strengths of both conventional model-based methods and machine learning (ML) techniques to address these challenges.
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- Recent advancements in radiotherapy for pancreatic cancer highlight the need for better research models to enhance our understanding of radiation treatment's effects on this cancer type.
- Cone-beam CT imaging is limited in its ability to provide soft tissue contrast and is affected by pancreatic motion, leading to potential damage to healthy tissues during treatment.
- The new bioluminescence tomography (BLT)-guided system shows improved localization accuracy for pancreatic tumors and allows for more precise radiation planning while minimizing damage to surrounding healthy tissue.
Article Synopsis
- Ultra-high dose rate irradiation (FLASH) can reduce damage to normal tissues while effectively controlling tumors, likely due to a reduction in oxygen levels (radiolytic oxygen depletion).
- Despite some experiments not confirming this global tissue hypoxia with FLASH, they may have missed local effects like preserving stem cell niches because of limitations in their measurement techniques.
- To better understand these microscopic dynamics, a detailed computational model was developed to explore how oxygen consumption and transport change over time in tissues during FLASH irradiation.
Article Synopsis
- - The study presents a unified treatment planning system (TPS) model for four matched Elekta VersaHD linacs, allowing flexible workflows in radiation therapy and ensuring quality assurance in intensity-modulated radiation therapy (IMRT).
- - The TPS was validated using comprehensive tests based on established guidelines, demonstrating that the single RayStation model delivered accurate results within recommended tolerance limits when compared to individual models.
- - The results showed that the single model maintained high agreement (within 1% PDD) across different radiation energies and produced consistent IMRT quality assurance outcomes, confirming its effectiveness for clinical use.
Article Synopsis
- Cone-beam computed tomography (CBCT) techniques face challenges in targeting soft tissue, which limits accuracy in small animal radiation studies.
- To improve localization, the researchers developed a new bioluminescence tomography-guided system (BLT, MuriGlo) aimed at enhancing imaging for pre-clinical research.
- The study included various tests to evaluate the system's performance and precision, ultimately providing a guideline for researchers on using BLT in radiation studies.
Inter- and intra-fractional prostate motion can deteriorate the dose distribution in extremely hypofractionated intensity-modulated proton therapy. We used verification CTs and prostate motion data calculated from 1024 intra-fractional prostate motion records to develop a voxel-wise based 4-dimensional method, which had a time resolution of 1 s, to assess the dose impact of prostate motion. An example of 100 fractional simulations revealed that motion had minimal impact on planning dose, the accumulated dose in 95 % of the scenarios fulfilled the clinical goals for target coverage (D95 > 37.
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- - SPBLT is a new imaging technique designed to track single or a small number of cells in living organisms.
- - The method relies on detecting bioluminescent signals, which are very faint, emitted by these cells.
- - Simulations have been created to test and confirm how well SPBLT can pick up these weak signals.
Article Synopsis
- Researchers developed a bioluminescence tomography (BLT) system to identify soft tissue targets in preclinical radiotherapy studies.
- The system uses specific thresholds and margins to define target volumes, enhancing targeting accuracy.
- This technology allows for more precise conformal irradiation of cancerous tissues.
Article Synopsis
- A cone-beam computed tomography system is less effective at identifying soft tissue targets due to low imaging contrast, prompting the development of a mobile bioluminescence tomography (BLT) system for improved localization in small animal irradiation.
- The BLT combines a light propagation model with optimization to generate detailed images of internal bioluminescent sources, achieving target localization accuracy within 1 mm.
- This technology offers researchers a new approach for precise, biology-guided radiation treatment for cancerous tissues by selecting optimal threshold and margin settings for target volumes.
Article Synopsis
- Bioluminescence imaging and tomography (BLT) are techniques used to study biological activities in mice, but their accuracy is limited by unknown optical properties of the tissues involved.
- A new optimization algorithm has been developed to simultaneously determine both the optical properties and the location of bioluminescent sources using surface measurements.
- The algorithm can accurately locate bioluminescence sources within 1 mm, achieving results comparable or superior to existing methods that require prior knowledge of optical parameters, thus enhancing molecular imaging capabilities.
Article Synopsis
- Specialized photonanomedicines (PNMs) have evolved to be activated by energy sources like near-infrared radiation, high-energy particles, and acoustic waves, enabling deeper tissue penetration than visible light.
- These PNMs utilize both direct activation (e.g., upconversion and scintillation) and indirect activation methods (e.g., sonoluminescence and Cerenkov radiation) to enhance deep-tissue cancer treatment.
- The review assesses current preclinical research on deep-tissue activation mechanisms and discusses the potential for clinical application, highlighting ways to adapt existing clinical equipment for effective photodynamic therapy.
Article Synopsis
- Several groups are working on small-animal irradiators that mimic human radiation therapy, primarily using cone-beam computed tomography (CBCT) for guidance.
- While CBCT is effective, it struggles with identifying soft tissue targets due to low image contrast; bioluminescence imaging (BLI) offers better contrast but is limited when used on the animal's surface.
- To overcome these challenges, the authors introduce a method called quantitative bioluminescence tomography (QBLT), which integrates 3D imaging with the small animal radiation research platform (SARRP) to improve tumor volume quantification for precise irradiation guidance.
Quantitative Bioluminescence Tomography-Guided Conformal Irradiation for Preclinical Radiation Research.
Int J Radiat Oncol Biol Phys
December 2021
Article Synopsis
- The study developed a high-contrast quantitative bioluminescence tomography (QBLT) system to improve target localization in radiation therapy, addressing limitations of conventional cone beam computed tomography (CBCT) that struggles with soft tissue imaging.
- QBLT utilizes advanced imaging techniques to accurately quantify bioluminescence signals in vivo, significantly enhancing radiation treatment planning for brain tumors like glioblastoma.
- Results showed QBLT could localize tumors with an accuracy of within 1 mm, improving tumor coverage from 75% to 97.9% and effectively delivering the prescribed radiation dose while minimizing damage to surrounding healthy tissue.
Purpose: Variation in target positioning represents a challenge to set-up reproducibility and reliability of dose delivery with stereotactic body radiation therapy (SBRT) for pancreatic adenocarcinoma (PDAC). While on-board imaging for fiducial matching allows for daily shifts to optimize target positioning, the magnitude of the shift as a result of inter- and intra-fraction variation may directly impact target coverage and dose to organs-at-risk. Herein, we characterize the variation patterns for PDAC patients treated at a high-volume institution with SBRT.
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- This study investigated the consistency of tumor positioning in pancreatic cancer patients receiving stereotactic body radiation therapy (SBRT) with deep-inspiration breath holds, focusing on variations between treatment and simulation using fiducial markers.
- Twenty patients were analyzed, and various scans were taken to measure and compare positional variations, leading to the development of a patient-specific breath-hold (PSBH) margin to enhance treatment accuracy.
- Results showed that incorporating the PSBH margin increased the internal target volume (ITV) by an average of 21%, suggesting a more effective method to ensure over 95% coverage of the tumor during SBRT.
Article Synopsis
- A genetically engineered mouse model (GEMM) for pancreatic ductal adenocarcinoma (PDAC) is being used to enhance our understanding of radiotherapy techniques suitable for pancreatic cancer treatment.
- The study highlights the limitations of cone beam CT (CBCT) for localizing PDAC, particularly in low-contrast environments, and introduces bioluminescence tomography (BLT) as a more effective alternative for guiding radiation treatment.
- Initial findings indicate that BLT can accurately determine the tumor's location within 2 mm and volume within 25% accuracy, providing a solid foundation for future radiation research using the PDAC-GEMM model.
Article Synopsis
- The study explores using a new radiation therapy method, biology-guided radiation therapy (BgRT), which utilizes PET imaging to improve precision in treating oligometastatic prostate cancer (OMPC) compared to conventional stereotactic ablative radiation therapy (CSABR).* -
- Researchers re-evaluated treatment plans for 15 patients using a specialized treatment planning system that integrates PET imaging, aiming to optimize BgRT while comparing it to previously used CSABR techniques in terms of dose delivery and target coverage.* -
- Results showed that BgRT significantly increased the dose delivered to tumors and reduced exposure to nearby organs at risk, while maintaining similar target coverage, indicating potential advantages over traditional CSABR methods.*
Article Synopsis
- The proposed mobile fluorescence tomography (mFT) system aims to enhance pre-clinical radiotherapy research.
- It will help accurately locate tumors and functional targets for radiation treatment.
- Additionally, the mFT system will allow for ongoing evaluation of treatment effectiveness over time.
Cancer recurrence after surgery remains an unresolved clinical problem. Myeloid cells derived from bone marrow contribute to the formation of the premetastatic microenvironment, which is required for disseminating tumour cells to engraft distant sites. There are currently no effective interventions that prevent the formation of the premetastatic microenvironment.
View Article and Find Full Text PDFIn Vivo Bioluminescence Tomography Center of Mass-Guided Conformal Irradiation.
Int J Radiat Oncol Biol Phys
March 2020
Article Synopsis
- - The study introduces a new method of using three-dimensional bioluminescence tomography (BLT) in conjunction with a small animal radiation research platform (SARRP) to improve targeting accuracy for radiation therapy in a glioblastoma mouse model, particularly where poor imaging contrast exists.
- - By optimizing the optical absorption coefficients in BLT, the researchers aimed to enhance the localization of the tumor's center of mass, ultimately allowing for more precise delivery of radiation therapy.
- - Results indicated that the BLT-guided method successfully achieved a target volume estimated to cover over 95% of the tumor, with a deviation of approximately 1 mm between the BLT method and traditional imaging techniques.
Purpose: Nonhomogeneous dose optimization (NHDO) is exploited in stereotactic body radiation therapy (SBRT) to increase dose delivery to the tumor and allow rapid dose falloff to surrounding normal tissues. We investigate changes in plan quality when NHDO is applied to inverse-planned conventionally fractionated radiation therapy (CF-RT) plans in patients with non-small cell lung cancer.
Methods And Materials: Patients with near-central non-small cell lung cancer treated with CF-RT in 2018 at a single institution were identified.
Quantitative bioluminescence tomography using spectral derivative data.
Biomed Opt Express
September 2018
Article Synopsis
- Bioluminescence imaging (BLI) is an optical technique that measures light emitted from biological activity, often used in studies to track disease progression and develop treatments, particularly in cancer research.
- The goal of bioluminescence tomography (BLT) is to create accurate maps of light source distribution within the body, which requires overcoming challenges in light propagation modeling and detector optics.
- A new method introduced in this study utilizes the spectral derivative of BLI images to significantly reduce reconstruction errors, improving the accuracy of source intensity mapping from 49% to 4%.
Article Synopsis
- Mutant KRAS enhances the glycolytic process in lung cancer, particularly affecting protein glycosylation through the hexosamine biosynthetic pathway (HBP).
- In a mouse model, it was shown that HBP activity promotes lung tumor growth by upregulating enzymes associated with epithelial-mesenchymal transition (EMT), a process linked to cancer progression.
- Elevated O-linked β-N-acetylglucosamine (O-GlcNAcylation) modifies proteins and has been found to suppress cellular senescence and further drive lung tumorigenesis, showing a direct correlation with the cancerous processes influenced by KRAS.
Article Synopsis
- Researchers developed a bioluminescence tomography (BLT) system to improve imaging for soft-tissue targets in small animal radiation research, addressing limitations of traditional CT methods.
- The study involved comparing the localization accuracy of this off-line BLT system with an on-line system using small animal irradiators, testing the impact of animal transport between the two imaging setups.
- Results showed a strong correlation (over 0.95) between imaging from both systems and minimal positional offset (0.2 mm), supporting the feasibility of using an off-line BLT for accurate radiation guidance.