TBI lung dose comparisons using bilateral and anteroposterior delivery techniques and tissue density corrections.

This study compares lung dose distributions for two common techniques of total body photon irradiation (TBI) at extended source-to-surface distance calculated with, and without, tissue density correction (TDC). Lung dose correction factors as a function of lateral thorax separation are approximated for bilateral opposed TBI (supine), similar to those published for anteroposterior-posteroanterior (AP-PA) techniques in AAPM Report 17 (i.e.