LETTER TO THE EDITOR
Thoughts on
“Estimation of radiation exposure of children
undergoing superselective intra-arterial chemotherapy
for retinoblastoma treatment: assessment of local diagnostic
reference levels as a function of age, sex, and interventional success
”
Sara Leonini1 &Eugenio Bertelli2&Sandra Bracco3&Andrea Guasti4
Received: 7 October 2020 / Accepted: 14 October 2020
# Springer-Verlag GmbH Germany, part of Springer Nature 2020
Dear Editor,
We read with great interest the recent article entitled“Estimation of radiation exposure of children undergoing superselective intra-arterial chemotherapy for retinoblastoma treatment: assess-ment of local diagnostic reference levels as a function of age, sex, and interventional success” by Opitz et al. [1].
The manuscript highlights the importance of establishing diagnostic reference levels (DRLs) for intra-arterial chemo-therapy (IAC) procedures and reports radiation exposure in a cohort of pediatric patients stratified by age.
In a previous report [2], my colleagues and I addressed the issue of radiation exposure in this particular population reporting main radiation parameters (including DAP) in a sim-ilar number of IAC procedures (216 treatments). In our opin-ion, optimization of neurointerventional procedures is the most important step to take for radiological teams in order to reduce doses and maximize results as recommended by the European Commission. For this reason, we divided the overall procedure in five distinct phases and DAP and fluoroscopy time values were recorded and analyzed for each phase.
Regarding the technique, we noticed that Opitz et al. re-ported a treatment failure by direct catheterization of the
ophthalmic artery (OA) in 16.5% (1). Notably in a remarkable percentage of children, we observed unfavorable patterns of OA flow that required different routes of drug infusion [3]. Our dosimetric investigation also included and discussed those cases where drug administration was performed by al-ternative routes through the external carotid artery and that required longer fluoroscopy time [2].
Finally, we would like to share with the authors our most important observation. A limitation of Opitz et al. report is that they did not provide any insight on the absorbed doses. Our work was aimed to validate a method that ultimately estimate with good approximation the absorbed doses of internal organs during IAC procedure starting from DAP values. Indeed a series of preliminary measurements with an anthropomorphic phantom are required in order to generate conversion factors that are specific to the settings and equipment employed in the angiographic room. Nonetheless in our opinion, the cumula-tive toxic effect from repeated IAC sessions is an essential topic especially for high radiosensitive tissues in the body such as lens and thyroid gland. Our results demonstrated that, in experienced hands, the dose ranges are lower than thresholds for deterministic and stochastic risk, including those children that required less straightforward interventional procedure.
In conclusion, we can only welcome the useful and valu-able contribution of this paper but we emphasize the necessity of developing validated methods for prospective radiation tracking and risk stratification.
Sincerely,
Funding No funding was received for this study.
Compliance with ethical standards
Conflict of interest The authors declare that they have no conflict of interest.
* Sara Leonini s_leonini@yahoo.it
1 Unit of Neuroimaging, Azienda Ospedaliera Universitaria Senese,
Siena, Italy
2
Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
3
Unit of Interventional Neurororadiology, Azienda Ospedaliera Universitaria Senese, Siena, Italy
4 Department of Medical Physics, Azienda USL Toscana sud est,
Siena, Italy Neuroradiology
Ethical approval All procedures performed in the studies involving hu-man participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent Informed consent was obtained from all individual participants included in the study.
References
1. Opitz M, Bos D, Deuschl C, Radbruch A, Zensen S, Sirin S, Forsting M, Bechrakis N, Biewald E, Bornfeld N, Ketteler P, Timmermann B, Stuschke M, Guberina M, Wetter A, Göricke S, Guberina N (2020) Estimation of radiation exposure of children undergoing superselective intra-arterial chemotherapy for retinoblastoma treat-ment: assessment of local diagnostic reference levels as a function
of age, sex, and interventional success. Neuroradiology.https://doi. org/10.1007/s00234-020-02540-7
2. Guasti A, Leonini S, Bertelli E, Baldi R, Gennari P, Cioni S, Vallone IM, Romano DG, Casseri T, Guerrini L, La Rocca AE, Scala PGD, De Francesco S, Hadjistilianou T, Bracco S (2019) Intra-arterial che-motherap y f or retinoblastoma: t he d osimetric impact. Neuroradiology. 61(9):1083–1091. https://doi.org/10.1007/s00234-019-02260-7
3. Bertelli E, Leonini S, Galimberti D, Moretti S, Tinturini R, Hadjistilianou T, De Francesco S, Romano DG, Vallone IM, Cioni S, Gennari P, Galluzzi P, Grazzini I, Rossi S, Bracco S (2016) Hemodynamic and anatomic variations require an adaptable ap-proach during intra-arterial chemotherapy for intraocular retinoblas-toma: alternative routes, strategies, and follow-up. AJNR Am J Neuroradiol 37(7):1289–1295.https://doi.org/10.3174/ajnr.A4741
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