A patient previously treated with radiation for base-of-tongue cancer presented with recurrent disease seven years later. The spinal cord had received tolerance dose. Using state-of-the-art treatment planning techniques, including beam's-eye-view and volumetrics, dose-volume histograms, split field technique, mixed energies, and beam intensity modulation (with a compensator), we achieved uniform dose coverage of the target in 3-D. This was verified in vivo with thermoluminescence dosimeters positioned in the esophagus by means of a nasogastric tube that ran centrally through the target volume. The various techniques applied will be presented with a discussion of the rationale used in each step of plan optimization and verification.
- Treatment planning