“…Second, the selection of what dose per fraction to use may not be straightforward. Simultaneous integrated boost IMRT (SIB-IMRT) plans, which are usually preferred over IMRT plans with sequential field reductions due to ease of treatment planning and more conformal dose distributions [17,33], deliver different doses per fraction to each of the target volumes over the same total number of fractions. When using once-a-day SIB-IMRT schedules, the dose per fraction to the elective regions and to the gross tumor typically ranges from 1.6 to 2.2 Gy [18].…”