Dose discrepancy between planning system estimation and measurement in backbone stereotactic physique radiation remedy: A case report.
J Med Imaging Radiat Oncol. 2017 Oct;61(5):695-698
Authors: Arumugam S, Berry M, Ochoa C, Xing A, Beeksma B, Vial P
Stereotactic physique radiation remedy (SBRT) to deal with spinal metastases has proven glorious scientific outcomes for native management. Excessive dose gradients wrapping round spinal wire make this therapy technically difficult. On this work, we current a backbone SBRT case the place a dosimetric error was recognized throughout pre-treatment dosimetric high quality assurance (QA). A affected person with metastasis in T7 vertebral physique consented to bear SBRT. A twin arc volumetric modulated arc remedy plan was generated on the Pinnacle therapy planning system (TPS) with a 6 MV Elekta machine utilizing gantry management level spacing of four°. Customary pre-treatment QA measurements have been carried out, together with ArcCHECK, ion chamber in CTV and spinal wire (SC) area and movie measurements in a number of planes. Whereas the dose measured at CTV area confirmed good settlement with TPS, the dose measured to the SC was considerably greater than reported by TPS within the authentic and repeat plans. Acceptable settlement was solely achieved when the gantry management level spacing was lowered to three°. A probably dangerous dose error was recognized by pre-treatment QA. TPS parameter settings used safely in standard therapies ought to be re-assessed for complicated therapies.
PMID: 28477339 [PubMed – indexed for MEDLINE]