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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:22 |
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Conference: Bucharest University Faculty of Physics 2024 Meeting
Section: Biophysics; Medical Physics
Title:
Evaluation of stereotactic treatment plan quality indexes
Authors:
Tia POPESCU (1,2), Mihai BARHALA (1,2), Madalina CROITORIU (1), Valentin COSTACHE (1,2), Ionut DUMITRU (1), Corina DRAGOI (1), Gratiela NITESCU (1), Mirela RADU (1)
*
Affiliation:
1) Neolife Bucharest
2) University of Bucharest, Faculty of Physics
E-mail
tiap20@yahoo.com
Keywords:
Brain, Stereotactic, Radiosurgery, Radiotherapy treatment plan
Abstract:
Brain tumor control plays an important role in the patient’s neurological integrity and quality of life. The principle underlying radiosurgery treatments is the delivery of large doses, up to 24 Gy/fraction (1), to the tumor, sparing the healthy normal tissues. In order to obtain the best results a very precise delivery is necessary, which depends on several factors, such as immobilization devices, daily imaging, surface guidance, and a rigorous quality assurance program to maintain a sub-millimeter accuracy. The closer the prescription dose is matched to the treated target and the steeper the dose gradient around the target, the less normal tissue is irradiated. For most rigorous evaluation of stereotactic treatment plans, parameters such as gradient index, conformity index or the gradient in millimeters must be evaluated (2). All these parameters depend on volume position, dimension, their position in relation to other critical structures or the beam energy. This work aims to compare the indices used in the evaluation of stereotactic treatments by making several treatment plans, in several radiotherapy departments, to see the variability from planner to planner and how far can go in conforming doses for such treatments, thus in order to standardize the quality of plans. The selected patients have single brain metastases, with volumes ranging from 0,3 cm3 to 100 cm3, some of them being close to critical structures. This analysis is based on comparing the values obtained in clinical practice with an experimental model which is based on a phantom, treated with a hypothetical treatment, which cannot be achieved in practice.
References:
1) Adler J. R. et al., Stereotactic radiosurgical treatment of brain metastases, Journal of Neurosurgery 76, 3, 444-449, 1992
2) Kocher M. et al., Stereotactic radiosurgery for treatment of brain metastases. Strahlentherapie und Onkologie, 190, 6, 521, 2014
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