@Mjheke I was very fortunate in that my rads oncologist gave it to me (maybe because I'm an age pensioner). But you could ask your rads nurses if they know; or maybe the hospital pharmacy might have it. It's also available online. It's currently on sale price with a good reduction here:
https://www.myskinpharmacy.com.au/product/strataxrt-50g/The 50 g tube was enough for my whole treatment (25 days + weekends) and for a few days after the end. You only need the tiniest bit. Put a tiny dot on and use the palm of your hand to wipe it across the skin. It forms a sort of second skin. Your skin becomes shiny.