The influence of a six degrees of freedom couch and an individual head support in patient positioning in radiotherapy of head and neck cancer

Myra F Rodrigues; Sten Veen; Jaap van Egmond; Mark van Hameren; Theodorus van Oorschot; Steven de Vet; Jan P C van Santvoort; Ruud G J Wiggenraad; Mirjam E Mast

doi:10.1016/j.phro.2019.07.001

The influence of a six degrees of freedom couch and an individual head support in patient positioning in radiotherapy of head and neck cancer

Phys Imaging Radiat Oncol. 2019 Jul 26:11:30-33. doi: 10.1016/j.phro.2019.07.001. eCollection 2019 Jul.

Authors

Myra F Rodrigues^{1

2}, Sten Veen¹, Jaap van Egmond³, Mark van Hameren¹, Theodorus van Oorschot¹, Steven de Vet¹, Jan P C van Santvoort³, Ruud G J Wiggenraad¹, Mirjam E Mast¹

Affiliations

¹ Department of Radiation Oncology, Haaglanden Medical Center, Burgemeester Banninglaan 1, 2262 BA Leidschendam, The Netherlands.
² Department of Radiation Oncology, Erasmus MC Cancer Institute, Doctor Molewaterplein 40, 3015 GD Rotterdam, The Netherlands.
³ Department of Medical Physics, Haaglanden Medical Center, Burgemeester Banninglaan 1, 2262 BA Leidschendam, The Netherlands.

Abstract

Reproducible patient positioning is important in radiotherapy (RT) of head-and-neck cancer. We therefore compared set-up errors in head-and-neck RT resulting from three different patient positioning systems. Patients were either treated with a standard head support (SHS) and conventional treatment couch (SHS-3, n = 10), a SHS and rotational couch (SHS-6, n = 10), or an individual head support (IHS) and rotational couch (IHS-6, n = 10). Interfraction mean translation vector lenghts were significantly lower for IHS-6 compared to SHS-3 (0.8 ± 0.3 mm vs. 1.4 ± 0.7 mm, P = 0.001). Intrafraction displacement was comparable among cohorts. This study showed that the use of a six degrees of freedom couch combined with an IHS in head-and-neck RT resulted in better interfraction reproducibility.

Keywords: Cone-beam CT; Head support; Head-and-neck cancer; Immobilization; Set-up correction; Six degrees of freedom couch.