Paediatric PET/CТ examinations – survey of practice and potential for optimisation
- Kostova-Lefterova, V. Hadzhiyska, Sh. Masso, F. Vasileva
The use of hybrid methods and imaging systems in medicine is becoming increasingly popular. Radiation dose of patients with РЕТ/CT examinations is relatively low, but they need more than one procedure, leading to possible significant increase in the cumulative dose. This is of great importance for paediatric patients because of their higher tissue sensitivity and longer life expectancy. The aim of the study was to collect data from paediatric РЕТ/CT examinations and to to explore potential for optimisation. The median value for CTDIvol for whole-body РЕТ/CT varies between 1.2 mGy and 3.8 mGy for the different paediatric age groups. In adult patients, the median value was 3.4 mGy for CTDIvol (1.8 mGy – 10.2 mGy). For head examinations, the median for CTDIvol varies between 1.8 mGy and 2 mGy for the different age groups. The median value for DLP in РЕТ/КТ for head is 44.2 mGy.cm – 48.6 mGy. cm and 97 mGy.cm – 225 mGy.cm for whole-body examination, while in adult patients the values are 44 mGy.cm and 365 mGy.cm. The median value for the 18F-FDG activity per kg body weight for head is 7.8 MBq/kg for children (1-4 years), 4.8 MBq/kg for (5-9 years), 3.5 MBq/kg (10-15 years) and 1.1 MBq/kg for adult patients; and for whole- body: 5.1 MBq/kg for the age group (1-4 years), 4.3 MBq/kg (5-9 years), 4.1 MBq/kg (10-15 years) ) and 1.6 MBq/kg for adult patients. The survey and optimisation process is still in progress. The purpose of ongoing studies is to define optimal exposure CT parameters, minimal РЕТ acquisition durations and administered activities for each patient category.
Key words: PAEDIATRIC РЕТ/CT EXAMINATIONS. ОPTIMIZATION. PATIENT DOSE. ADMINISTERED ACTIVITY