Tumour-on-a-chip Device. (a) Photograph of complete chip set-up. (b) Schematic of tumour-on-a-chip. All dimensions are shown in Supplementary Fig. S1. (c) Irradiation set up: PMMA phantom for tumour-on-a-chip device (milling outlined in red); placement of TLD or PCTS (outlined in yellow); Tumour-on-a-chip housed in phantom; XStrahl unit applied to phantom and device.