Tissue Lateral Effect


Tissue lateral effect (TLE) describes the situation in which, for parallel opposed beams, the dose near the surface becomes large relative to the dose at mid-plane for larger patients and for treatments with lower energies.

Tissue lateral effect becomes unacceptable when the maximum dose approaches 120% of mid-line dose.

Methods to Reduce TLE

  • Increase treatment energy
  • Change treatment position to reduce patient thickness
  • Increase the number of beam angles