Comparison of Linear Accelerator and Helical Tomotherapy Plans for Glioblastoma Multiforme Patients

Background: Despite advances in radiotherapy, overall survival of glioblastoma multiforme (GBM) patientsis still poor. Moreover dosimetrical analyses with these newer treatment methods are insufficient. The currentstudy is aimed to compare intensity modulated radiation therapy (IMRT) linear accelerator (linac) and helicaltomotherapy (HT) treatment plans for patients with prognostic aggressive brain tumors. Material and
Methods:A total of 20 GBM patient plans were prospectively evaluated in both linac and HT planning systems. Plans arecompared with respect to homogenity index, conformity index and organs at risk (OAR) sparing effects of thetreatments.
Results: Both treatment plans provided good results that can be applied to GBM patients but it wasconcluded that if the critical organs with relatively lower dose constraints are closer to the target region, HTfor radiotherapeutical application could be preferred.
Conclusion: Tomotherapy plans were superior to linearaccelerator plans from the aspect of OAR sparing with slightly broader low dose ranges over the healthy tissues.In case a clinic has both of these IMRT systems, employment of HT is recommended based on the observedresults and future re-irradiation strategies must be considered.