A pEdiatRic dosimetRy personalized platfORm based on computational anthropomorphic phantoms

Project Information

ERROR

Grant agreement ID: 691203

DOI

10.3030/691203

Project closed

EC signature date 5 October 2015

Start date 1 January 2016

End date 31 December 2019

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 432 000,00

EU contribution

€ 432 000,00

Coordinated by

PANEPISTIMIO PATRON
Greece

Periodic Reporting for period 2 - ERROR (A pEdiatRic dosimetRy personalized platfORm based on computational anthropomorphic phantoms)

Reporting period: 2018-01-01 to 2019-12-31

Summary of the context and overall objectives of the project

Patient-specific internal dosimetry is of great interest, especially in childhood and puberty where the relative risk from the exposure to ionizing radiation compared to that for adults is widely debated. Pediatric dosimetry has been extensively discussed over the last two decades, in terms of administered activity reduction while retaining acceptable image quality of standalone acquisitions (CT,SPECT,PET) or hybrid examinations (SPECT/CT, PET/CT, PET/MR). The radiation absorbed dose delivered to pediatric patients in diagnostic and therapeutic procedures is still a matter of concern. Monte Carlo simulations is the gold standard method for accurate dosimetry assessment. However, due to complexity and large computational time needed, they are not applied in clinical routine. Instead, for couple of decades, there have been dosimetry factors calculated through MC techniques and are still applied for the estimation of the absorbed dose. Modern medicine requires alternative and updated techniques to approach personalized dosimetry, considering patient's individual anatomical characteristics.

The main goal of the ERROR is the creation of a framework, freely available to the scientific community for the dose assessment on specific organs of interest in pediatric diagnostic and therapeutic applications. A novel methodology is applied to calculate dose factors for a pre-defined children population, acquiring realistic simulations, in terms of physics modeling, human anatomy, activity distribution/irradiation, low statistical uncertainty. The dosimetry framework will provide the definition of absorbed dose per organ according to the age, gender, weight, administered activity, duration time and the examination. In collaboration with the 3 academic partners, there is a novel combination of several methodologies and tools for achieving personalized pediatric dosimetry. Machine learning techniques, GPU based MC simulations, detailed anthropomorphic models, image processing algorithms, clinical pediatric data and feedback from clinicians will be used to facilitate the dosimetry calculation for each pediatric patient, based on pre-calculated data.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

WP1-Project management:
There is an efficient management of the project. Good communication among all partners. 100% of the total seconded months have been performed. 11 research and 5 ethical deliverables were approved. No training schools organized yet.

WP2-Collection of clinical data - creation of pediatric population:
During the 1st year of the project, standardized clinical protocols were reviewed. A common route should be defined for all beneficiaries providing data to the project. To the present 5 PET/CT, 6 SPECT datasets and 2 Brachytherapy TPs acquired from the collaborating institutions. Furthermore, 28 pediatric computational models have been included in the pediatric population for the simulated dosimetry data. Automated segmentation techniques were standardized to segment basic organs of the pediatric CT data. The rest of the organs are manually segmented by clinicians. There is ongoing work to optimize the creation of our own pediatric models.

WP3-Pediatric dosimetry:
The method for personalized dosimetry has been standardized in NM & CT examinations extracting simulated dose factors for the pediatric population. A new methodology called SADRs was proposed and validated against standard NM dosimetry techniques (S-values). A database was created using clinical biodistribution data of 6 different radiopharmaceuticals. 1 CT scanner was also modeled and validated against experimental data (CTDI), while 3 other are in progress on validation. CT dosimetry datasets were also created for pediatric patients. Brachytherapy treatment plan has been evaluated and optimized for dosimetry in pediatrics. Furthermore, a list of 6 commercial brachytherapy seeds were accurately simulated and validated against TG-43 protocol.

WP4-Data integration in a platform:
Results of WP2 & WP3 were needed, in order to be integrated. Databases have now been developed. All the simulated results and the datasets have been organized and analyzed to specify the parameters that will be used for the personalization of pediatric dosimetry. The ERROR's procedures are standardized, utilizing the individual characteristics and calculating dosimetry which will be used in the final framework of the project. It is work in progress to integrate the databases.

WP5-Development of software for personalization and optimization:
The methodology for extracting absorbed doses per organ through the created simulated data has been developed. The necessary data have now been collected to proceed to the implementation of the software. Initial GUI was developed related to the brachytherapy database and will be integrated in the final software. The design and the functionalities of the software have been defined.

WP6-Dissemination / Exploitation / Training:
The identity of ERROR was defined including project logo, poster, brochure, presentation and deliverable template and the creation and continuous update of the official ERROR's website. Several participations took place both in scientific and public events, disseminating and communicating the project. Since the 1st period of the project, there are:
3 active social media
2 journal publications and 2 journal publications under review.
7 publications in conference proceedings and 1 conference abstract submission.
2 participations in public events.
1 participation in a workshop.
4 invited lectures.
2 open-days organized for medical students and hospital staff/clinicians.
3 collaborations with institutions and organizations.
4 training activities.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

ERROR is a project combing multidisciplinary scientists in the medical physics and biomedical engineering field. The domain of pediatric personalized dosimetry is of high interest with scientific, clinical and social impact. ERROR's proposed approach is likely to lead to a significant breakthrough in internal dosimetry, especially for pediatric patients.
There are currently no existing tools to clinically:
i) evaluate absorbed dose for different exams and therapeutic plans at different pediatric patients in terms of age, gender, overall size and organ size, using the suggested protocols;
ii) assess different imaging and therapeutic protocols for optimizing dosimetry based on patient individual personalized characteristics.
iii) provide the clinician the information of the expected absorbed dose in organ level, before the execution of the examination.
Such tools have already been developed by the creation of pediatric dosimetry databases and brachytherapy seeds' validation dataset. A novel methodology has been proposed (SADRs) for calculating doses/organ considering individual patients' anatomical characteristics.

The goal is to develop software tools for personalized dosimetry, with emphasis in children, its impact is expected to extend beyond the end of this project. Progress made along the development of the objectives can lead to new expertise and know-how that could be extrapolated to other medical needs. It is foreseen that the academic partners could strongly benefit from this interaction in terms of accessing information regarding open needs for developments that can lead to future collaborations. Alongside, the dosimetry platform can be exploited by the 2 SMEs, which will strengthen and enhance their position in the European market.

image for summary publication