Radioprotection 2024 , 59 ( 1 ), 50 – 54 © SFRP , 2024 https :// doi . org / 10.1051 / radiopro / 2023047
Available online at : www . radioprotection . org
ARTICLE Establishment of local diagnostic reference levels for breast cancer CT protocols in radiotherapy in a single Moroccan center
O . Nhila 1 ,* , M . Talbi 2 , M . A . Youssoufi 3 , M . El Mansouri 1 , Z . Tahiri 4 , 5 , E . M . Chakir 1 and M . Azougagh 6
1 Ibn Tofail University , Faculty of Sciences , Department of Physics , laboratory of materials and subatomic physics , Kenitra , Morocco . 2 Moulay Ismail University , Faculty of Sciences , Meknes , Morocco . 3 National Institute of Oncology , University Hospital Center , Rabat , Morocco . 4 Biophysics Laboratory , Life and Health Sciences Research Laboratory , Faculty of Medicine and Pharmacy of Tangier , Abdelmalek
Essaâdi University . 5 Mohammed V University , Faculty of Medecine and Pharmacy , Rabat , Morocco . 6 Mohammed V University , National Graduate School of Arts and Crafts , Rabat , Morocco .
Received : 28 August 2023 / Accepted : 11 December 2023 Abstract – The objective of this study was to establish local diagnostic reference levels ( LDRLs ) for breast cancer computed tomography imaging in radiotherapy ( CT-RT ) at a single hospital in Morocco . Data were collected from 106 adult breast cancer patients aged between 33 and 78 yr during five months . Data were obtained using a Hitachi Supria 16-slice CT simulator at a regional oncology center in Morocco . CT-RT images are intended for 3D conformal radiotherapy treatment planning . Dose length product ( DLP ) and volumetric computed tomography dose index ( CTDIvol ) were evaluated by determining the 75th percentile as diagnostic reference levels for CT-RT breast cancer . LDRLs for CT-RT breast cancer have been determined in terms of DLP and CTDIvol , and they were 330.4 mGy . cm and 6.8 mGy , respectively . The DRLs were compared with other Europeans study . DRLs for this study were lower than those for the United Kingdom ( UK ), Croatia and Slovenia . The results of this study can be a reference for the establishment of local and national DRLs in Morocco and the optimization of CT-RT breast cancer procedures .
Keywords : DRL / Computed tomography / ALARA principle / breast cancer CT protocols
1 Introduction
The current global cancer data estimates that 19.3 million new cases were diagnosed in 2020 . Most notably , breast cancer , with over 2.3 million cases reported in this year , was the most prevalent form of cancer ( Sung et al ., 2021 ). Morocco is also affected by this global scourge . The estimated number of new cancer cases per year is close to 50,000 , of which breast cancer is the most frequently diagnosed among Moroccan women , accounting for 20 % of all cancer cases , according to data from the country ’ s cancer registry ( Ministry of Health , Morocco , 2020 ). Radiotherapy is an inherent integral part of oncology care . Thus , more than 60 % of cancer patients receive radiotherapy as their principal treatment ( Doury , 2019 ).
The most crucial and commonly used imaging modality in radiotherapy is CT ( Computed Tomography ) ( Nhila et al ., 2023 ). All patients receiving radiotherapy undergo dosimetric
* Corresponding author : nhila . oussama @ gmail . com
CT scans for treatment planning . Thus , the increase in cancer incidents implies a rise in the number of performed CT scans , which in turn leads to an increase in the number of individuals exposed to ionizing radiation from CT scans . Even if CT doses are considered well below therapeutic doses , they must be monitored and kept as low as possible ( ALARA principal ) ( Clerkin , Brennan and Mullaney , 2018 ). According to the linear no-threshold model , all ionizing radiation imaging processes , including CT simulations for radiotherapy , must be optimized to reduce risks , especially for cancer patients with long life expectancies ( Zalokar et al ., 2020 ). Diagnostic reference levels ( DRLs ) are the most commonly used tool for optimizing and identifying unusually high doses to patients from radiological examinations ( Paulo et al ., 2020 ; Elnour et al ., 2021 ). In fact , the principles of DRLs as a tool for the optimization of patient doses were first established in 1996 through ICRP publication 73 and were updated in publication 135 from the same institution in 2017 ( Talbi et al ., 2022 ). DRLs should not be considered a boundary between acceptable and unacceptable medical practices or as dose