Methods and Materials
Designing and implementing a CT Dose Management strategy across 9 countries,
for 53 CT systems from 3 vendors,
with 20 different CT models,
in both the private and public healthcare sectors is a challenging task.
In order to achieve this,
collaboration among radiologists,
medical physicists,
technologists,
and those tasked with quality improvement and change management is essential.
The structure of the teams and their interaction,
the communication channels,
each team member’s responsibilities and tasks,
the processes and goals must be clearly outlined and communicated.
The data collection from different models of CT systems supplied by different vendors requires a vendor-neutral dose tracking software.
The dose tracking software assists in the automatic recording and analysis of CT dose metrics,
but it is up to the user to evaluate variability between the same protocols,
the setting of dose reference levels,
benchmarking,
the prevention of excessive medical radiation exposure and achieving an evidence-based balance between image quality and dose.
Last but not least,
an essential element to achieve a comprehensive campaign is a structured communication plan to inform patients and referring doctors of radiation risks and dose management,
and to the staff to optimize the processes.
The Affidea Dose Excellence Campaign
Affidea Dose Excellence Countries
The Affidea Dose Excellence campaign was initiated in March of 2014 in 3 countries and 16 CT departments.
Today,
the campaign has been successfully implemented in 9 countries and 53 CT departments (figure 1).
Teams,
Communication Channels,
Responsibilities and Tasks
For the design and implementation of the campaign,
multidisciplinary teams have been assigned at Affidea headquarters,
country and center level.
As external bodies,
the dose tracking software team,
CT vendor advanced application specialist teams and service providers support the Affidea teams at different levels.
Each team and team member has clear responsibilities and tasks to achieve.
The structure of the communication channels is designed to facilitate information transfer and avoid any implementation errors (figure 2).
Dose Tracking Software
For the multi-parameter and multivendor data recording and analysis,
Affidea chose GE HeathCare DoseWatch™ software (figure 3).
Affidea Standardized Adult CT Protocols
An essential part of the campaign was the drafting of the list of 65 standardized adult CT protocols.
The CT protocols are categorized by anatomic area and clinical indication.
Information in the Affidea protocols list includes acquisition mode,
accepted number of exposures,
protocol sequence details,
DoseWatch mapping ID and 3rd percentile Dose Reference Levels (DRLs) for CTDIvol and DLP.
All departments have unified the CT protocol names,
which are based on the clinical indication of the examination,
to ensure that the radiographers select the correct protocol,
as well as the accurate comparison of protocols between CT systems.
Affidea Standard Operating Procedures and Guidelines
A set of standard operating procedures and guidelines has been created for the comprehensive implementation of the assigned processes.
Standard procedures include; quality control of CT systems,
the justification of high dose level alerts,
the mapping of site CT protocols to the Affidea Standardized Adult CT Protocols.
CT Dose Metrics and Other Parameters Tracked for Analysis
The CT dose metrics recorded for analysis are CTDIvol,
DLP,
SSDE and effective dose.
Other parameters that are also recorded are; justification of high dose level alerts,
body mass index (BMI),
patient age,
radiographer initials,
number of exposures.
Justification,
Standardization and Optimization Report
A monthly report has been created,
in collaboration with the GE HealthCare DoseWatch™ team,
to analyse the data collected and assess compliance of justification of high dose level alerts,
examinations performed with standardized protocols and dose levels applied when protocols are followed.
The report includes a dashboard for the visual assessment of the 3 parameters,
as well as other detailed information (figures 4,
5).
The center and country teams review the reports on a monthly basis to decide on corrective actions required to improve the practice.
Affidea Dose Reference Levels
Affidea DRLs have been set according to international published data from 2012 onwards [6].
Optimization of Protocol Parameters
Protocols of the same clinical indication and CT model are compared for dose benchmarking.
Corrections of protocol parameters are performed for protocols with dose levels above 3rd quartile DRLs.
Further optimization of the protocols and personalized patient care will in the future include BMI,
image reconstruction algorithms and parameters,
contrast media protocols,
dose reduction algorithms and special patient categories.
Image Quality and Dose Optimized Protocols
To align radiation dose and image quality,
the image quality of each protocol in the first quartile with low doses and in the third quartile with high doses is assessed by a panel of disease specialized radiologists using a double blinded rating system.
The methodology used for the analysis of the data is Fleiss kappa for interrater reliability,
VGA for observer performance evaluation and ordinal regression analysis to combine dosimetric results with image analysis results.
Further assessment of the optimized protocols is performed with anthropomorphic phantoms to evaluate low contrast and noise.
Education
Comprehensive education is provided to radiologists and radiographers on different aspects and expertise levels including MDCT technology,
dose reduction algorithms,
communication of risk to patients,
protocol settings for obese patients,
impact of CT protocol parameters on dose and image quality.
Affidea Communication Plan
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Brochures with information addressed to patients and referring doctors have been specially created [figures 6,
7].
Administrative personnel,
marketing teams and managers have also been trained to address patient questions.