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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:30 |
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Conference: Bucharest University Faculty of Physics 2023 Meeting
Section: Biophysics; Medical Physics
Title:
The care and management of patients with indication for intracavitary 3D brachytherapy
Authors:
Andreea IONESCU (BAICAN)(1), Ancuța Elena BACIU(2), Claudia Gabriela CHILOM(1), Amalia CONSTANTINESCU(2), Bogdan Cosmin TANASE(2)
Affiliation:
1) Department of Electricity, Solid Physics and Biophysics, Faculty of Physics, University of Bucharest, Măgurele, Romania
2) Oncological Institute ,, Prof. Dr. Alexandru Trestioreanu” Bucharest
E-mail
andreea.ionescu998@yahoo.com
Keywords:
3D brachytherapy, cervix carcinoma, intracavitary
Abstract:
Our work assesses the strategy of designing intracavitary 3D brachytherapy treatment plans for cervical malignant lesions with ganglionic infiltration, using the Miami applicator and the vaginal applicator. Specifically, external radiotherapy was applied to the patient, in a total dose of 45 Gy with 1.8 Gy per fraction, 25 sessions, 5 days a week, over a period of 5 weeks. Immediately after the completion of the treatment, intracavitary irradiation is continued, in 3 sessions with the fractionation of 7.5 Gy per session. The first irradiation is a Miami-type application followed by two vaginal applications with a vaginal applicator. We show that is possible to deliver the highest possible dose of radiation to a tumor while affecting as little as possible the surrounding healthy tissues.
A number of three plans were made, one plan for the Miami application and two plans with the same isodoses for the vaginal applications, and evaluated in terms of computerized dosimetry parameters such as dose-volume histograms, with regards for the organs at risk (OAR) like bladder and rectum. In order to examine the quality and extent to which the treatment plans agree with the general rules prescribing the radiation exposure of surrounding organs to radiological risk, we compared the results against the EMBRACE II recommendations concerning the values of the dose constraints for OARs. In most cases, all prescribed doses were delivered appropriately while protecting the adjacent organs as much as possible. However, in a certain case, the values obtained for the bladder and for the rectum exceeded the benchmarks due to the fact that these organs were anatomically too close to the target volume. In such circumstances, according to the ALARA principle (As Low As Reasonable Achievable), an optimization was performed to reduce the exposure without adversely affecting the dose distribution.
References:
E.B. Podgorsak, Radiation Physics for Medical Physicists, 2010, Springer
E.B. Podgorsak, Radiation Oncology Physics: A Handbook for Teachers and Students, 2005, International Atomic Energy Agency, Vienna
Walter Prendiville, Colposcopy and Treatment of Cervical Cancer, 2017, IARC Technical Publication no. 45
Larisa V. Volkova, Alexander I. Pashov, Nadezhda N. Omelchuk, Cervical Carcinoma: Oncobiology and Biomarkers, 2021
Richard Potter, Kari Tanderup et. al. ,, The EMBRACE II study: The outcome and prospect of two decades of evolution within the GEC-ESTRO GYN working group and the EMBRACE studies”, 2018
C. A. Joslin, A. Flynn, E.J Hall, Principles and Practice Of Brachytherapy Using Afterloading Systems, 2001
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