Assessing the patient experience of anal and rectal cancer MR simulation for radiotherapy treatment planning

Aim: The patient experience of radiotherapy magnetic resonance (MR) simulation is unknown. This study aims to evaluate the patient experience of MR simulation in comparison to computed tomography (CT) simulation, identifying the quality of patient experience and pathway changes which could improve patient experience outcomes. Materials and Methods: MR simulation was acquired for 46 anal and rectal cancer patients. Patient experience questionnaires were provided directly after MR simulation. Questionnaire responses were assessed after 33 patients (cohort one). Changes to the scanning pathway were identified and implemented. The impact of changes was assessed by cohort two (13 patients). Results: Response rates were 85% (cohort one) and 54% (cohort two). 75% of cohort one respondents found the magnetic resonance imaging (MRI) experience to be better or similar to their CT experience. Implemented changes included routine use of blankets, earplugs and headphones, music and feet-first positioning and further MRI protocol optimisation. All cohort two respondents found the MRI experience to be better or similar to the CT experience. Findings: MR simulation can be a comfortable and positive experience that is comparable to that of standard radiotherapy CT simulation. Special attention is required due to the fundamental differences between CT and MRI scanning.

Alcohol keeps eDNA at the party longer

For a typical eDNA water study, water will be filtered on site, before prompt transfer to a laboratory for DNA extraction and required scientific analysis. In a setting where transport is quick and available, this is a straightforward process. However, many of our studies can occur in remote Australia where sample preservation presents many logistical challenges. Typically, we advise clients to store eDNA water filters after sampling below 4 °C to ensure minimal DNA degradation. For many clients however, field studies often occur in an isolated setting without adequate refrigeration facilities, and as such present challenges for this process. Rather than compromise on sample integrity, EnviroDNA conducted a pilot study into the use of alternate preservation methods on our most commonly used 0.22 mm Sterivex filters. With help from our friendly neighbourhood goldfish tank, our standard 4 °C protocol was compared to a variety of conditions including filled ethanol filters, flushed ethanol filters, lysis buffer and silica bead storage conditions at both 4 °C and room temperature. The study, conducted at various time points over 14-days, used qPCR to quantify the amount of DNA extracted from the filter. Our results revealed that storage within or using flushed ethanol, allowed the samples to be stored for longer time intervals at room temperature, with similar, or in some cases, improved DNA elutions. This protocol optimisation has allowed us to offer an alternate sample storage protocol for clients, expanding the availability and accessibility of eDNA biodiversity assessments around Australia.

Evaluation of low contrast resolution and radiation dose in abdominal CT protocols by a difference detail curve (DDC) method

The use of optimised CT protocols regarding radiation exposure is a legal requirement. Since low contrast visibility is intrinsically varying within the CT slice, there is no adequate method for optimisation of dose and image quality. We developed a method to access image quality in a way that represents the situation closer to a real patient. This method is based on a novel difference detail curve (DDC) phantom with low contrast objects representing native tissue contrast and contrast media with different densities and diameters. The position of the contrast objects have been evaluated by a noise level analysis of CT slices of different manufactures. The dose – length – product can be measured within the phantom simultaneously. For all tested manu-factures and CT protocols, the noise analysis revealed a similar spatial variation of the signal -to-noise ratio (SNR). For the DDC method, contrast steps of 6 (4-8) Hounsfield Units (HU) are adequate. For the different CT units, comparable low contrast detectability is associated with remarkably varying dose levels (CTDI range from 8 to 18 mGy for native contrast and 9-16 mGy for contrast media). The novel DDC phantom is sensitive to protocol optimisations and therefore suitable for rating subtle effects caused by protocol optimisation.