What proportion of CT scan patients are alive or deceased after 10 years?

Purpose: When discussing radiation risks for patients who undergo many CT examinations, some question the risks, believing that most of these patients are already very sick and likely to die within a few years, thus negating worry about radiation risk. This study seeks to evaluate the validity of this notion.

Methods: In this retrospective single large-hospital study, patients who received CT exams in 2013 were sorted into four cumulative effective dose (CED) groups: Group A (>0 to <10 mSv), Group B (10 to <50 mSv), Group C (50 to < 100 mSv), and Group D (≥100 mSv).

Dose, dose, dose, but where is the patient dose?

The article reviews the historical developments in radiation dose metrices in medical imaging. It identifies the good, the bad, and the ugly aspects of current-day metrices. The actions on shifting focus from International Commission on Radiological Protection (ICRP) Reference-Man-based population-average phantoms to patient-specific computational phantoms have been proposed and discussed.

Recurrent medical imaging exposures for the care of patients: one way forward.

Medical imaging is both valuable and essential in the care of patients. Much of this imaging depends on ionizing radiation with attendant responsibilities for judicious use when performing an examination. This responsibility applies in settings of both individual as well as multiple (recurrent) imaging with associated repeated radiation exposures.

Impact of equipment technology on reference levels in fluoroscopy-guided gastrointestinal procedures.

Objectives: To evaluate the effect of equipment technology on reference point air kerma (K), air kerma-area product (P), and fluoroscopic time for fluoroscopically-guided gastrointestinal endoscopic procedures and establish benchmark levels.

Methods: This retrospective study included the consecutive patients who underwent fluoroscopically-guided gastrointestinal endoscopic procedures from May 2016 to August 2023 at a tertiary care hospital in the U.S.

Characterizing imaging radiation risk in a population of 8918 patients with recurrent imaging for a better effective dose.

An updated extension of effective dose was recently introduced, namely relative effective dose ( ), incorporating age and sex factors. In this study we extended application to a population of about 9000 patients who underwent multiple CT imaging exams, and we compared it with other commonly used radiation protection metrics in terms of their correlation with radiation risk. Using Monte Carlo methods, , dose-length-product based effective dose ( ), organ-dose based effective dose ( ), and organ-dose based risk index ( ) were calculated for each patient.

Is a one percent occurrence of high-dose patients significant?

Risk-free society is utopian. We come across risks in everyday life, and we use probabilities to get a feel of how risky a situation is. Risk probability numbers of around 1% are comforting, but an intercomparison of numbers among various low risks in popular situations can be enlightening.

Neurointerventions on two generations of angiography systems: Recent systems reduce radiation exposure by half.

Purpose: Fluoroscopically-guided neurointervention may be associated with prolonged procedure time and substantial radiation exposure to the patient and staff. This study sought to examine technological features affecting the potential radiation exposure reduction of new angiography systems, compared to older systems, for neurointerventional procedures.

Methods: Consecutive neurointerventional patients (2020-2022) were retrospectively analyzed.

Cumulative radiation exposure from multimodality recurrent imaging of CT, fluoroscopically guided intervention, and nuclear medicine.

Objectives: To assess cumulative effective dose (CED) over a 4-year period in patients undergoing multimodality recurrent imaging at a major hospital in the USA.

Methods: CED from CT, fluoroscopically guided intervention (FGI), and nuclear medicine was analyzed in consecutive exams in a tertiary care center in 2018-2021. Patients with CED ≥ 100 mSv were classified by age and body habitus (underweight, healthy weight, overweight, obese), as per body mass index percentiles < 5, 5 to < 85, 85 to < 95, and ≥ 95 (age 2-19 years), and its ranges < 18.

Global status of medical physics human resource - The IOMP survey report.

Purpose: Realizing the need for periodic surveys about global medical physics human resource, the International Organization for Medical Physics (IOMP) performed a third survey following the previous two (2015 and 2018). The objective was to collect information about the current numbers of medical physicists (MPs) in individual countries, about their MP training, and accreditation pathways.

Methods: The survey was designed using Google Forms.

Losing the balance in risk-benefit analysis.

The idea of a benefit-risk analysis has been used for decades, but no one has probably bothered to see if there is a ratio or even questioned the concept because it does give an intuitive sense. There are situations where the tendency to lose the balance between the risk and benefit has been observed to move either towards benefit alone or risk alone. This may happen in medicine for benefit alone and in the nuclear industry for risk alone when public perceptions are involved.

Do patients with larger body sizes undergo more CT exams?

Background: Overweight and obese patients are known to have more diseases than normal weight individuals, but it is currently unknown if there is higher utilization of computed tomography (CT) exams among those with larger body sizes.

Aims: To examine whether patients with larger body sizes undergo more CT exams and by how much more.

Methods: Using the recently described T-shirt size assessed from the lateral and transverse dimensions in CT localizer radiographs as a surrogate for body size, patients were classified into seven T-shirt sizes (XXS, XS, S, M, L, XL, XXL).

Patient follow-up for possible radiation injury from fluoroscopically-guided interventions: Need to consider high cumulative exposure from multiple procedures.

Purpose: Patient skin dose from interventional fluoroscopy procedures may exceed the threshold of tissue injuries and established guidelines recommend patient follow-up for air kerma at reference point (K) ≥ 5 Gy for individual procedures. Patients may undergo multiple procedures and skin injuries may be possible by cumulative exposure, even when individually insufficient to cause injury. This study sought to quantify the frequency of patients whose individual procedure doses are below 5 Gy but whose cumulative K is ≥ 5 Gy.

Accounting for radiation exposure from previous CT exams while deciding on the next exam: What do referring clinicians think?

Purpose: To obtain clinicians' views of the need to account for radiation exposure from previous CT scans and the advisability of a regulatory mechanism to control the number of CT scans for an individual patient.

Methods: A convenience survey was conducted by emailing a link to a three-question electronic survey to clinicians in many countries, mostly through radiology and radiation protection contacts.

Results: 505 responses were received from 24 countries.

The International Organization for Medical Physics - a driving force for the global development of medical physics.

The International Organization for Medical Physics (IOMP) is the world's largest professional organization in the field of medical physics and has official non-governmental organization status with the World Health Organization (WHO) and the International Atomic Energy Agency (IAEA). IOMP is charged with a mission to advance medical physics practice worldwide by disseminating scientific and technical information, fostering the educational and professional development of medical physics and promoting the highest quality medical services for patients. IOMP's activities are directed towards the promotion of medical physics globally, improving patient care, and contributing to the benefit of healthcare to the society.

T-shirt size as a classification for body habitus in computed tomography (CT) and development of size-based dose reference levels for different indications.

Purpose: To examine the impact of patient size on dose indices and develop size-based reference levels (50th and 75th percentiles) for 20 body CT exams for routine and organ-specific clinical indications.

Methods: Based on effective diameter estimated from adult body CT, each acquisition was classified into T-shirt size as XXS, XS, S, M, L, XL, and XXL. Radiation dose indices for each size and each exam type were correlated.

Patients undergoing multiple F-FDG PET/CT exams: Assessment of frequency, dose and disease classification.

Objective: To analyse the frequency, demographics, primary disease and cumulative effective dose of patients undergoing two or more F-FDG PET/CT examinations in a year.

Methods: In a retrospective study performed at a tertiary-care hospital, patients who underwent ≥2 F-FDG PET/CT scans in a calendar year were identified for two consecutive years. The CT radiation dose was calculated using dose-length-product and sex-specific conversion factors.

Communication of radiation risk from imaging studies: an IAEA-coordinated international survey.

The purpose of this IAEA-coordinated international study was to understand aspects related to the communication of radiation risk from imaging studies, such as how often imaging department personnel and referring physicians are asked about radiation risks in diagnostic imaging, who asks about these risks, how often professionals are able to provide satisfactory answers using qualitative metrics and how often quantitative risk estimates are needed. A web-based questionnaire with ten questions was completed by 386 healthcare professionals from 63 countries from all four continents, including clinicians/referring physicians (42.5%), radiologists or nuclear medicine physicians (26.

Establishment of national diagnostic reference levels for percutaneous coronary interventions (PCIs) in Thailand.

Purpose: To establish national diagnostic reference levels (DRLs) for percutaneous coronary intervention (PCI) in Thailand for lesions of different complexity.

Methods: Radiation dose quantity as kerma-area-product (KAP) and cumulative air-kerma at reference point (CAK) from 76 catheterization labs in 38 hospitals in PCI registry of Thailand was transferred online to central data management. Sixteen months data (May 2018 to August 2019) was analyzed.

Organ doses and cancer risk assessment in patients exposed to high doses from recurrent CT exams.

Purpose: To estimate cumulative organ doses and age- and gender-stratified cancer mortality risks in patients undergoing recurrent computed tomography (CT) exams.

Methods: Cohorts of patients who received cumulative effective dose ≥ 100 mSv were stratified into age and gender groups. Organ doses of 27 organs using Monte Carlo methods were available, and the relative risk model from the Biological Effects of Ionizing Radiation VII (BEIR VII) was used to estimate lifetime attributable cancer mortality risks (LACMR).