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Erschienen in:
15.12.2015 | Physics
The role of Size-Specific Dose Estimate (SSDE) in patient-specific organ dose and cancer risk estimation in paediatric chest and abdominopelvic CT examinations
Erschienen in: European Radiology | Ausgabe 8/2016
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Objectives
To develop a clinically applicable method to estimate patient-specific organ and blood doses and lifetime attributable risks (LAR) from paediatric torso CT examinations.
Methods
Individualized voxel models were created from full-body CT data of 10 paediatric patients (2–18 years). Patient-specific dose distributions of chest and abdominopelvic CT scans were simulated using Monte Carlo methods. Blood dose was calculated as a weighted sum of simulated organ doses. LAR of cancer incidence and mortality were estimated, according to BEIR-VII. A second simulation and blood dose calculation was performed using only the thoracic and abdominopelvic region of the original voxel models. For each simulation, the size-specific dose estimate (SSDE) was calculated.
Results
SSDE showed a significant strong linear correlation with organ dose (r > 0.8) and blood dose (r > 0.9) and LAR (r > 0.9). No significant differences were found between blood dose calculations with the full-body voxel models and the thoracic or abdominopelvic models.
Conclusion
Even though clinical CT images mostly do not cover the whole body of the patient, they can be used as a voxel model for blood dose calculation. In addition, SSDE can estimate patient-specific organ and blood doses and LAR in paediatric torso CT examinations.
Key Points
• Blood dose can be simulated using the patient’s clinical CT images.
• SSDE estimates patient-specific organ/blood dose and LAR in paediatric CAP CT-examinations.
• SSDE makes on-the-spot dose and LAR estimations possible in routine clinical practice.