Dosimetry of Continuous Random Motion in High Dose Rate Strontium-90 Plesiotherapy.

Strontium-90 plesiotherapy delivers high doses of radiation to superficial lesions (<3 mm depth) with excellent sparing of deeper tissues. The sealed-source applicator tip is circular and 8-10 mm in diameter. Larger treatment fields are treated with multiple overlapping fields.

Positional and angular tracking of HDR Ir source for brachytherapy quality assurance using radiochromic film dosimetry.

Purpose: To quantify and verify the dosimetric impact of high-dose rate (HDR) source positional uncertainty in brachytherapy, and to introduce a model for three-dimensional (3D) position tracking of the HDR source based on a two-dimensional (2D) measurement. This model has been utilized for the development of a comprehensive source quality assurance (QA) method using radiochromic film (RCF) dosimetry including assessment of different digitization uncertainties.

Methods: An algorithm was developed and verified to generate 2D dose maps of the mHDR-V2 Ir source (Elekta, Veenendaal, Netherlands) based on the AAPM TG-43 formalism.

Calibration of MTT assay in proton beams using radiochromic films.

Purpose: This study provides methodology of calibrating as well as controlling the output for an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay irradiated in a low energy proton beam using EBT3-model GAFCHROMIC film, without correcting for quenching effect.

Methods: A calibrated Markus ionization chamber was used to measure the depth dose and beam output for 26.5 MeV protons produced by a CS30 cyclotron.

Association Between Culture-Negative Versus Culture-Positive Sepsis and Outcomes of Patients Admitted to the Pediatric Intensive Care Unit.

Background Sepsis remains a major cause of death, with high mortality and morbidity rates in children. The cause of mortality may be associated with several factors, including differences in cultures and the type of organism. This study was aimed at evaluating the characteristics and outcomes of negative bacterial blood culture compared to those of positive bacterial blood culture in children with severe sepsis/septic shock.

Towards customizable thin-panel low-Z detector arrays: electrode design for increased spatial resolution ion chamber arrays.

The purpose of the present development is to employ 3D printing to prototype an ion chamber array with a scalable design potentially allowing increased spatial resolution and a larger active area. An additional goal is to design and fabricate a custom size thin-panel detector array with low-Z components. As a proof of principle demonstration, a medium size detector array with 30 × 30 air-vented ion chambers was 3D-printed using PLA as frame for the electrodes.