Application of 2 Step IMRT to Spinal Tumors: A Preliminary Retrospective Planning Study Comparison with Classical IMRT

摘要

A geometry based treatment methodology, 2 Step IMRT, was employed to perform a retrospective planning study for spinal tumors. Four such tumor localisations were considered: 3 cases with a single treatment volume and one case with two nested treatment volumes. Four simple metrics were defined and used to evaluate the quality of the plans. The results show that 2 Step IMRT performs at least as well as a reference plan, simultaneously maintaining or improving the dose coverage of the PTV(s), the dose gradient near the dominant organ at risk (spinal column) and reducing the number of segments required for treatment delivery. Currently the generation of 2 Step segments is labor intensive. However, this will be automated in the near-future to enable a more comprehensive study to be performed.