Timmy Siauw

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PURPOSE Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is(More)
— Brachytherapy is a widely-used treatment modality for cancer in many sites in the body. In brachytherapy, small radioactive sources are positioned proximal to cancerous tumors. An ongoing challenge is to accurately place sources on a set of dwell positions to sufficiently irradiate the tumors while limiting radiation damage to healthy organs and tissues.(More)
— Automation seeks to improve the reliability and quality of processes. This study aims to automate high dose rate brachytherapy (HDR-BT), a radiation therapy that places radioactive sources at the site of the tumor using needles. Although HDR-BT has a high rate of clinical success in curing prostate cancer, it also has several side effects related to(More)
The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A(More)
PURPOSE In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and(More)
PURPOSE Three-dimensional (3D) printing technology allows physicians to rapidly create customized devices for patients. We report our initial clinical experience using this technology to create custom applicators for vaginal brachytherapy. MATERIAL AND METHODS Three brachytherapy patients with unique clinical needs were identified as likely to benefit(More)
Purpose: To evaluate the radiation attenuation properties of PC-ISO, a bio-compatible, steril-izable 3D printing material and its suitability for customized gynecologic (GYN) brachytherapy 15 applicators. Method: A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO. The apparatus contained a single catheter channel and a slit to hold a(More)
— When planning skew-line needle arrangements for automated brachytherapy, one objective is to identify a set of candidate needles that enter from a specified entry region, avoid specified organs-at-risk and sufficiently cover the target (tumor) volume. Existing methods use uniform or random sampling to generate a set of candidate needles, which may not(More)
Purpose: Recent advances in real time 3D ultrasound, EM tracking, needle position optimization , and rapid prototyping support a radically new prostate high dose rate (HDR) brachytherapy workflow that uses custom needle guides to insert needles. The purpose of this study is to evaluate one part of this workflow: the needle placement error associated with(More)