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Radiobiological rationale for stereotactic hypofractionated radiosurgery Part II. Normal tissue tolerance — dose constraints
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Abstract
The response of normal tissues/organs to SHRS is more complex than to conventional radiotherapy. Tolerance doses TD5/5 and TD50/5, proposed by Rubin and Casarett, cannot be simply used for SHRS. Instead of LQED2, the BED is advised. The term risk dose (RD) corresponds better than TD to the risk of late morphological and functional disorders (OAR). BED doses show a rapid gradient with increasing distance of the OAR from the tumour GTV. Other risk factors include the dose-volume relationship, OAR organization (serial or parallel) and the ratio of the FSU to the target call. Vasculoendothelial cell damage initiates series of processes resulting in clinical and functional late effect. Using available data and studies, RDmin and RDmax for doses are listed as physical and BED doses for various OAR and dose-volume constraints. The RD values and constraints are rough estimates, since the available SHRS data are sparse and fragmentary, which should be interpreted cautiously and need further clinical validation.
Abstract
The response of normal tissues/organs to SHRS is more complex than to conventional radiotherapy. Tolerance doses TD5/5 and TD50/5, proposed by Rubin and Casarett, cannot be simply used for SHRS. Instead of LQED2, the BED is advised. The term risk dose (RD) corresponds better than TD to the risk of late morphological and functional disorders (OAR). BED doses show a rapid gradient with increasing distance of the OAR from the tumour GTV. Other risk factors include the dose-volume relationship, OAR organization (serial or parallel) and the ratio of the FSU to the target call. Vasculoendothelial cell damage initiates series of processes resulting in clinical and functional late effect. Using available data and studies, RDmin and RDmax for doses are listed as physical and BED doses for various OAR and dose-volume constraints. The RD values and constraints are rough estimates, since the available SHRS data are sparse and fragmentary, which should be interpreted cautiously and need further clinical validation.
Keywords
SHRS, risk doses, OAR late effects, radiobiological mechanisms
About this articleTitle
Radiobiological rationale for stereotactic hypofractionated radiosurgery Part II. Normal tissue tolerance — dose constraints
Journal
Nowotwory. Journal of Oncology
Issue
Article type
Review paper
Pages
79-86
Published online
2018-08-08
Page views
901
Article views/downloads
816
DOI
Bibliographic record
Nowotwory. Journal of Oncology 2018;68(2):79-86.
Keywords
SHRS
risk doses
OAR late effects
radiobiological mechanisms
Authors
Bogusław Maciejewski
Sławomir Blamek
Krzysztof Składowski
Rafał Suwiński
Leszek Miszczyk
Krzysztof Ślosarek
Marcin Miszczyk