Radiation doses and Indications for Computed Tomography Scans among Pediatric Patients at a Tertiary Hospital in the Eastern Cape, South Africa

This study audits 543 pediatric CT scans at a South African tertiary hospital, finding that radiation doses generally align with international safety standards but are slightly higher during after-hours shifts, highlighting the need for consistent staff training and standardized protocols.

The Gist

Imagine you are a parent taking your child to the doctor because they have a bad headache or fell off a bike. The doctor needs to look inside your child's head to make sure everything is okay. They might suggest a CT scan.

Think of a CT scan like a super-powered camera that takes hundreds of X-ray pictures of your body and stacks them together to build a 3D model. It's amazing because it's fast and very clear, but there's a catch: it uses radiation.

For grown-ups, a little bit of radiation is usually fine. But for kids, it's like giving a small plant a little too much sun. Their bodies are still growing (like the plant), and their cells are dividing quickly, which makes them more sensitive to that "sunlight." Plus, because kids have a long life ahead of them, that tiny bit of extra sun could cause problems many years down the road.

The Problem: No "Speed Limit" Signs

In many rich countries, there are strict "speed limit signs" for how much radiation a hospital can use on a child. These are called Diagnostic Reference Levels (DRLs). Think of them as the speed limit on a highway: you can drive faster, but if you do, you're taking an unnecessary risk.

In South Africa, however, there weren't many of these "speed limit signs" for children's CT scans. Hospitals were driving, but no one knew exactly what the safe speed was.

The Study: Checking the Speedometer

This paper is like a report from a safety inspector who went to a big hospital in the Eastern Cape (Nelson Mandela Academic Hospital) to check the speedometers.

• Who they looked at: They checked the records of 543 children (ages 0 to 14) who had CT scans between 2021 and 2023.
• What they measured: They looked at two main numbers:
  1. How strong the radiation beam was (like the brightness of a flashlight).
  2. How long the beam was on (like how long you hold the flashlight on).

What They Found: The Good, The Bad, and The "After-Hours"

1. The Good News: Brain Scans are Safe
The most common scan they did was on the brain (86% of all scans).

• The Analogy: Imagine the hospital is a bakery. They make a lot of "Brain Cakes." The inspector checked the recipes and found that the amount of "radiation flour" they were using was perfectly in line with the best bakeries in Europe, Japan, and even other big hospitals in South Africa.
• Why this matters: It means the doctors and technicians are doing a great job protecting kids when they scan their heads. They are using the right settings.

2. The "After-Hours" Glitch
The inspector noticed something interesting about when the scans happened.

• The Analogy: Imagine a school cafeteria. During the day (9 AM to 4 PM), the chefs are well-rested, follow the recipe cards strictly, and use the right amount of ingredients. But late at night or on weekends, when the "night shift" chefs are tired or working alone, they sometimes accidentally put in a little extra "radiation spice."
• The Finding: Scans done after regular work hours or on weekends used slightly higher radiation doses. This suggests that maybe the night staff needs a little more training or a clearer checklist to ensure they don't turn up the "brightness" too high when no one is watching.

3. The Bad News: Chest and Belly Scans Need Work
While the brain scans were perfect, the scans for the chest and belly were using way too much radiation, especially for older kids.

• The Analogy: If the brain scan was like driving at the speed limit, the chest and belly scans were like speeding at 100 mph in a 50 mph zone.
• Why? The hospital often uses a "multi-phase" approach. Imagine taking a photo of a moving car. To make sure you don't miss anything, you take three or four photos in a row instead of just one. In a busy, resource-limited hospital, they do this to avoid having to call the child back for a second scan later (which would be worse). However, this "taking three photos" method doubles or triples the radiation dose.
• The Fix: They need to figure out how to get a clear picture with just one "photo" (or a smarter way to take the photos) to stop over-exposing the kids.

The Big Picture Takeaway

This study is like a health check-up for the hospital's safety habits.

• The Verdict: The hospital is doing a fantastic job with the most common scans (the brain), matching the best standards in the world.
• The To-Do List: They need to fix the "night shift" settings so everyone uses the same safe dose, and they need to rewrite the recipe for chest and belly scans to stop using so much radiation.

In short: The doctors are trying their best to keep kids safe. They have the right tools, but they need to make sure everyone uses them exactly the same way, no matter what time of day it is, and find a smarter way to scan the body without using so much "sunlight."

Technical Summary

Title

Radiation doses and Indications for Computed Tomography Scans among Paediatric Patients at a Tertiary Hospital in the Eastern Cape, South Africa.

1. Problem Statement

Computed Tomography (CT) is a critical diagnostic tool, particularly in low-to-middle-income countries (LMICs) where it is more accessible and cost-effective than MRI. However, CT scans involve ionizing radiation, which poses significant long-term health risks (e.g., cancer induction) to pediatric patients due to their higher radiosensitivity, rapid cell division, and longer life expectancy.

• The Gap: South Africa currently lacks national Diagnostic Reference Levels (DRLs) for pediatric CT imaging. Without standardized benchmarks, it is difficult to ensure radiation doses are "As Low As Reasonably Achievable" (ALARA).
• The Objective: To audit local radiation doses (CTDIvol and DLP) at a tertiary hospital, establish local DRLs, and compare them against national and international standards to identify areas for protocol optimization.

2. Methodology

• Study Design: Retrospective cross-sectional study.
• Setting: Nelson Mandela Academic Hospital (NMAH), a 700-bed tertiary referral center in the Eastern Cape, South Africa.
• Population: 543 pediatric patients (aged 0–14 years) scanned between January 2021 and December 2023.
• Sampling: Systematic sampling (every 15th scan) from a population of ~7,300 annual scans.
• Data Collection:
  • Parameters: CT Dose Index Volume (CTDIvol in mGy) and Dose Length Product (DLP in mGy·cm) at the 75th percentile.
  • Variables: Age groups (<1, 1–5, 6–10, >10 years), anatomical site (Brain, Chest, Abdomen), and time of scan (Routine hours vs. After-hours/Weekends).
  • Equipment: Philips Ingenuity Core 128-slice scanner (helical mode).
• Statistical Analysis: Descriptive statistics (means, medians, 75th percentiles) calculated using SPSS v27. Results were compared with data from Johannesburg hospitals, European guidelines (EDRL), and other international benchmarks (Germany, Japan, Kenya, Brazil).

3. Key Contributions

• Establishment of Local DRLs: Provided the first comprehensive set of baseline DRLs for pediatric CT at a major Eastern Cape tertiary center, filling a critical data gap in the absence of national standards.
• Protocol Optimization Insights: Identified specific discrepancies in radiation dosing based on time of day (after-hours) and anatomical region, offering actionable data for staff training and protocol revision.
• Comparative Benchmarking: Validated the hospital's performance against global and regional standards, demonstrating that while brain scans are optimized, chest and abdominal protocols require urgent review.

4. Key Results

• Demographics & Indications:
  • Brain CT was the dominant examination (86.6% of all scans), followed by Abdomen (8.1%) and Chest (5.3%).
  • The majority of patients were aged 6–10 years (48.6%) and >10 years (39.4%).
  • Most scans (76.4%) occurred during routine working hours (08:00–16:00).
• Radiation Dose Metrics (75th Percentile):
  • Brain: Doses were consistent across age groups (CTDIvol ~14–16 mGy). DLP increased with age (343.7 mGy·cm for <1 yr to 485.5 mGy·cm for >10 yr) due to longer scan lengths.
  • Chest & Abdomen: Data for infants (<1 yr) was sparse. For older children, doses were significantly higher than international benchmarks.
• Time-of-Day Variations:
  • Scans performed after-hours (including weekends) generally exhibited slightly higher DRLs compared to routine hours.
  • Notably, the >10 years age group showed a significant spike in CTDIvol during routine hours (19.92 mGy) compared to after-hours (15.80 mGy), though the abstract notes a general trend of higher after-hours doses.
• Comparative Analysis:
  • Brain CT: Institutional DRLs were comparable to Johannesburg hospitals and European benchmarks (e.g., NMAH Brain DLP for >10 yrs: 485.53 vs. Jhb: 746.10; EDRL: 650).
  • Chest CT: Institutional DLPs were substantially higher (up to 179% increase) than international DRLs for the 6–10 and >10 age groups.
  • Abdomen CT: DLPs were >100% higher than Johannesburg benchmarks for children aged 6–10 and >10.

5. Significance and Discussion

• Success in Brain Imaging: The study confirms that the institution's protocols for the most common pediatric scan (Brain) are well-optimized and align with global safety standards. This validates the current technical parameters for head imaging.
• Areas for Improvement:
  • Chest/Abdomen Protocols: The significantly elevated doses in chest and abdominal scans suggest the use of multiphase protocols (common in resource-constrained settings to avoid repeat scans due to lack of immediate review capabilities) rather than single-phase protocols used in Europe.
  • After-Hours Consistency: The variation in doses during off-hours suggests a need for standardized training and protocol adherence across all shifts to prevent unnecessary dose escalation.
• Clinical Implication: While the hospital is performing safely for head trauma (the primary indication), the high doses for thoracic and abdominal imaging pose unnecessary radiation risks. The authors recommend an urgent review of justification criteria and a shift toward single-phase scanning where clinically feasible, alongside enhanced staff training to ensure ALARA principles are applied consistently 24/7.

Conclusion: The study successfully established local DRLs, demonstrating that while the institution is a leader in pediatric brain imaging safety, significant optimization is required for body imaging to align with international standards and minimize long-term radiation risks for children.