Usefulness of Semi-cylindrical Beam Spoiler in Treatment of Early Glottic Cancer Using 6 MV Photon Beam

In Vivo. 2022 Jan-Feb;36(1):465-472. doi: 10.21873/invivo.12726.

Abstract

Background/aim: To assess the dosimetric influence of a semi-cylindrical beam spoiler (sCBS) for the treatment of early glottic cancer using a 6 MV photon beam.

Patients and methods: The 2D dose distributions were also calculated and measured with and without the sCBS and with a 0.5 cm thick bolus. A retrospective study of 8 patients treated between 2012 and 2018 was performed.

Results: The 2D dose distributions obtained from the treatment planning system (TPS) and film measurements were in good agreement. In the planning study, the V95%, V100%, conformal index (CI), and homogeneity index (HI) of all pPTVs for the sCBS plans were better than those for the open field plans (p<0.01). Especially, sCBS plans had better skin sparing effect than bolus plans (p<0.05).

Conclusion: The sCBS of the 6 MV photon beam could be a useful tool for the treatment of early glottic cancers.

Keywords: 6 MV; Beam spoiler; glottic cancer; photon beam; radiotherapy..

MeSH terms

  • Humans
  • Laryngeal Neoplasms* / radiotherapy
  • Radiometry
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted
  • Retrospective Studies