Optimisation of protection in the medical exposure of recurrent adult patients due to computed tomography procedures: development of recurrent exposures reference levels

Marco Bramilla; Luca Berton; Rosario F Balzano; Barbara Cannillo; Alessandro Carriero; Stephane Chauvie; Teresa Gallo; Samantha Cornacchia; Claudia Cutaia; Andrea D'Alessio; Roberto Emanuele; Paolo Fonio; Roberta Matheoud; Michele Stasi; Alberto Talenti; Osvaldo Rampado

doi:10.1007/s00330-023-10520-7

Optimisation of protection in the medical exposure of recurrent adult patients due to computed tomography procedures: development of recurrent exposures reference levels

Eur Radiol. 2023 Dec 21. doi: 10.1007/s00330-023-10520-7. Online ahead of print.

Authors

Marco Bramilla¹, Luca Berton², Rosario F Balzano³, Barbara Cannillo⁴, Alessandro Carriero⁵, Stephane Chauvie⁶, Teresa Gallo⁷, Samantha Cornacchia⁸, Claudia Cutaia⁹, Andrea D'Alessio⁴, Roberto Emanuele⁶, Paolo Fonio¹⁰, Roberta Matheoud⁴, Michele Stasi⁹, Alberto Talenti¹¹, Osvaldo Rampado²

Affiliations

¹ Medical Physics Department, University Hospital "Maggiore Della Carità", Novara, Italy. marco.brambilla@maggioreosp.novara.it.
² Medical Physics Department, A.O.U. Città Della Salute E Della Scienza Di Torino, Turin, Italy.
³ Radiology Department, ASL BT Ospedale Dimiccoli, Barletta, Italy.
⁴ Medical Physics Department, University Hospital "Maggiore Della Carità", Novara, Italy.
⁵ Radiology Department, University Hospital "Maggiore Della Carità", Novara, Italy.
⁶ Medical Physics Department, A.O. Santa Croce e Carle, Cuneo, Italy.
⁷ Radiology Department, A.O. Ordine Mauriziano, Turin, Italy.
⁸ Medical Physics Department, ASL BT Ospedale Dimiccoli, Barletta, Italy.
⁹ Medical Physics Department, A.O. Ordine Mauriziano, Turin, Italy.
¹⁰ Radiology Department, A.O.U. Città Della Salute E Della Scienza Di Torino, Turin, Italy.
¹¹ Radiology Department, A.O. Santa Croce e Carle, Cuneo, Italy.

PMID: 38127075
DOI: 10.1007/s00330-023-10520-7

Abstract

Objectives: To assess the incidence (1 year) and the cumulative incidence (3 years) of the condition of patients accruing cumulative effective doses (CED) of ≥ 100 mSv and their variability among different hospitals. To establish and validate a reference level for the CED in patients with recurrent exposures (RERL) and provide a RERL value.

Methods: Data of CT exposure was collected in 9 similar hospitals. The database included 294,222 patient*years who underwent 442,278 CT exams in 3 years. The incidence proportion of patients with CED ≥ 100 mSv in a given year (I_100;1) and the 3-year cumulative incidence of patients with CED ≥ 100 mSv over 3 consecutive years (I_100;3) were calculated and compared among different institutions.

Results: I_100;1 ranged from a minimum of 0.1% to a maximum of 5.1%. The percentage of recurrent patients was quite uniform among centres ranging from 23 to 38%. The I_100;3 ranged from a minimum of 1.1 to 11.4%. There was a strong positive correlation between the third quartile values of yearly CED and yearly incidence (r = 0.90; R² = 0.81; p < 0.0001). RERL value in our study was found at 34.0 mSv.

Conclusion: The management of patients with recurrent exposures is highly variable among hospitals leading to a 50-fold variation in I_100;1 and to a tenfold variation in I_100;3. RERL could be established and used by taking as a RERL quantity the CED and as a RERL value the 75th percentile of the third quartiles of the distribution of the yearly CED obtained by surveying different hospitals.

Clinical relevance statement: This is the first ever multicentre study that quantifies recurrent exposures in terms of incidence and cumulative incidence of patients with CED ≥ 100 mSv. RERL establishment and use could benefit the optimisation of radioprotection of patients with recurrent exposures.

Key points: This is the first multicentre study estimating yearly incidence and 3-year cumulative incidence of patients with cumulative effective doses ≥ 100 mSv. In this study, a 50-fold inter centre variation between the maximum (5.1%) and the minimum value (0.1%) of yearly incidence of patients with cumulative effective doses ≥ 100 mSv was reported. The range of the 3-year cumulative incidence extended from 1.1 to 11.4% (a tenfold variation) The third quartile of the yearly cumulative effective doses in a centre showed a strong positive correlation with the yearly incidence of patients with cumulative effective doses ≥ 100 mSv, with a potential of being used to set reference levels for recurrent exposures.

Keywords: Computed X-ray tomography; Incidence study; Radiation dosimetry; Radiation protection.