11.03 - 2D And 3D Planning

2D planning

2D planning refers to calculation of dose distribution considering two dimensions only. It is faster and often possible to perform by hand. It has the downside of much less accuracy, as the contribution of dose from structures above and below the 'slice' are assumed to be similar to the slice being used.

3D planning

3D planning takes into account the variations in dose distribution caused by scatter from multiple planes. A computer is typically required due to the increased complexity of dose calculation. Current computers are able to compute dose in three dimensions much more quickly than a human planner could acheive for a 2D plan.