We treat our chest wall patients with bolus at QEHB in Birmingham, UK. We leave the tolerance at 0.3cm and we don’t struggle any more than normal DIBH without bolus. We use 1.0cm think bolus slabs and we treat 2 or 3 field patients in this manner. If the bolus doesn’t conform well (breast re-con) we ask our mould room technicians to make us a custom gauze type bolus which is more flexible and sits on the skin surface better.
The only time we really struggle is for patients who struggled with BH for the first 8# anyway – then when we move to last 7# bolus, they continue to struggle and we end up replacing bolus and re-capturing etc. rather than managing with the original re-capture at the beginning of the session. We have never had problems because of the bolus i.e. if the patient coped well prior to bolus, we don’t see them struggle with bolus in place.
We do have to cover the bolus completely in paper as the reflection it shines back from the camera flash interferes with the surface capture. This makes the deltas more reliable and less jumpy as if the surface capture has ‘holes’ there is less for the system to monitor.