Operation and calibration of the novel PTW 1600SRS detector for the verification of single isocenter stereotactic radiosurgery treatments of multiple small brain metastases.

Content Provider	Europe PMC
Author	Decabooter, Esther Swinnen, Ans CC Öllers, Michel C Göpfert, Fabian Verhaegen, Frank
Copyright Year	2021
Abstract	Objectives:The aim of this work was to evaluate the operation of the 1600SRS detector and to develop a calibration procedure for verifying the dose delivered by a single isocenter stereotactic radiosurgery (SRS) treatment of small multiple brain metastases (BM).Methods:14 clinical treatment cases were selected with the number of BM ranging from 2 to 11. The dosimetric agreement was investigated between the calculated and the measured dose by an OCTAVIUS 1600SRS array detector in an OCTAVIUS 4D phantom equipped with dedicated SRS top. The cross-calibration procedure deviated from the manufacturer’s as it applied field sizes and dose rates corresponding to the volumetric modulated arc therapy segments in each plan.Results:Measurements with a plan specific cross-calibration showed mean ± standard deviation (SD) agreement scores for cut-off values 50%, 80%, 95%, of 98.6 ± 1.7%, 96.5 ± 4.6%, 97.3 ± 4.4% for the 6 MV plans respectively, and 98.6 ± 1.5%, 96.6 ± 4.0% 96.4 ± 6.3%, for the 6 MV flattening filter free (FFF) plans respectively. Using the default calibration procedure instead of the plan specific calibration could lead to a combined systematic dose offset of 4.1% for our treatment plans.Conclusion:The 1600SRS detector array with the 4D phantom offers an accurate solution to perform routine quality assurance measurements of single isocenter SRS treatments of multiple BM. This work points out the necessity of an adapted cross-calibration procedure.Advances in knowledge:A dedicated calibration procedure enables accurate dosimetry with the 1600SRS detector for small field single isocenter SRS treatment of multiple brain metastases for a large amount of BM.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC8248213&blobtype=pdf
ISSN	00071285
Journal	The British Journal of Radiology [Br J Radiol]
Volume Number	94
DOI	10.1259/bjr.20210473
PubMed Central reference number	PMC8248213
Issue Number	1123
PubMed reference number	34111967
e-ISSN	1748880X
Language	English
Publisher	The British Institute of Radiology.
Publisher Date	2021-06-11
Access Restriction	Open
Rights License	This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 Unported License http://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted non-commercial reuse, provided the original author and source are credited. © 2021 The Authors. Published by the British Institute of Radiology
Content Type	Text
Resource Type	Article
Subject	Radiology, Nuclear Medicine and Imaging