Image quality characterization of an ultra-high-speed kilovoltage cone-beam computed tomography imaging system on an O-ring linear accelerator.

Purpose: The quality of on-board imaging systems, including cone-beam computed tomography (CBCT), plays a vital role in image-guided radiation therapy (IGRT) and adaptive radiotherapy. Recently, there has been an upgrade of the CBCT systems fused in the O-ring linear accelerators called HyperSight, featuring a high imaging performance. As the characterization of a new imaging system is essential, we evaluated the image quality of the HyperSight system by comparing it with Halcyon 3.

Organ sparing treatment for penile cancer using a 3D-printed high-dose-rate brachytherapy applicator.

Purpose: We present a case study of the treatment of localized squamous cell carcinoma on the glans penis with a custom-fabricated high-dose-rate (HDR) brachytherapy applicator.

Methods And Materials: A cylindrically shaped applicator was fabricated with eight embedded channels suitable for standard plastic brachytherapy catheters. An additional custom silicone bolus/sleeve was designed to be used with the 3D-printed applicator to provide an additional offset from the source to skin to reduce the surface dose and for patient comfort.

Optimal energy selection for proton stopping-power-ratio estimation using dual-energy CT-based monoenergetic imaging.

The dual-energy computed tomography (DECT)-based approach holds promise in reducing the overall uncertainty in proton stopping-power-ratio (SPR) estimation, but cannot be easily implemented with most commercial proton treatment planning systems (TPS). In this study, we revisited the idea of coupling the stoichiometric calibration method with virtual monoenergetic CT datasets (MonoCT) generated by modern DECT scanners, because of its readiness for implementation with the existing TPS. Our objective was to determine the optimal energy of the MonoCT dataset for stoichiometric calibration and estimate the overall uncertainty in SPR estimation at the optimal energy.

Systematic analysis of the impact of imaging noise on dual-energy CT-based proton stopping power ratio estimation.

Purpose: Dual-energy CT (DECT) has been shown to have a great potential in reducing the uncertainty in proton stopping power ratio (SPR) estimation, when compared to current standard method - the stoichiometric method based on single-energy CT (SECT). However, a few recent studies indicated that imaging noise may have a substantial impact on the performance of the DECT-based approach, especially at a high noise level. The goal of this study is to quantify the uncertainty in SPR and range estimation caused by noise in the DECT-based approach under various conditions.

Why sexual health promotion misses its audience: men who have sex with men reading the texts.

Purpose: Sexual health promotion aimed at men who have sex with men (MSM) is not achieving its objective of reducing the incidence of new infections of sexually transmitted diseases, notably HIV/AIDS, in the MSM population. The paper aims to raise awareness of possible unintended consequences when using visual culture and advertising techniques in the field of sexual (and other) health promotion and public health messages.

Design/methodology/approach: Using critical textual analysis and drawing on visual culture methodology the approach is to critique current practice and suggest alternative ways to approach gay men's sexual health which are not predicated on a "model" gay man.