Measuring the dose in bone for spine stereotactic body radiotherapy

PurposeCurrent quality assurance of radiotherapy involving bony regions generally utilises homogeneous phantoms and dose calculations, ignoring the challenges heterogeneities with dosimetry problems likely occurring around bone. Anthropomorphic synthetic materials enable realistic end-to-end testing in clinical scenarios. This work reports on measurements calculated corrections required to directly report context comprehensive audit (63 plans, 6 planning systems).Materials methodsRadiochromic film microDiamond were performed an anthropomorphic spine phantom containing bone equivalent materials. Medium dependent correction factors, kmed, established using MV 10 Linear Accelerator Monte Carlo simulations account for detectors being calibrated water, but measuring material. Both cortical trabecular material investigated verification calculations dose-to-medium (Dm,m) dose-to-water (Dw,w) scenarios.ResultsFor Dm,m modelled factors measurements, 0.875(±0.1%), 0.953(±0.3%) 0.962(±0.4%), respectively. For Dw,w 0.920(±0.1%), 0.982(±0.3%) 0.993(±0.4%), In audit, application improves mean agreement between treatment plans measured from −2.4%(±3.9%) 0.4%(±3.7%).ConclusionMonte provide a method correcting allowing more accurate comparison system doses. algorithm specific should be applied variations based Dw,w.