Randomized self-controlled study comparing open-face vs. closed immobilization masks in fractionated cranial radiotherapy

Michèle Keane; Nienke Weitkamp; Indira Madani; Jonathan Day; Riccardo Dal Bello; Mariangela Zamburlini; Antonia Schiess; Amanda Moreira; Sophie Perryck; Katja Tomuschat; Marilyn Spencer; Stephanie Tanadini-Lang; Matthias Guckenberger; Michelle Brown

doi:10.1016/j.radonc.2024.110314

Randomized self-controlled study comparing open-face vs. closed immobilization masks in fractionated cranial radiotherapy

Radiother Oncol. 2024 Apr 25:196:110314. doi: 10.1016/j.radonc.2024.110314. Online ahead of print.

Affiliations

¹ Department of Radiation Oncology, University Hospital Zürich and University of Zürich, Rämistrasse 100, 8091, Zürich, Switzerland.
² Department of Radiation Oncology, University Hospital Zürich and University of Zürich, Rämistrasse 100, 8091, Zürich, Switzerland. Electronic address: michelleleanne.brown@usz.ch.

PMID: 38677329
DOI: 10.1016/j.radonc.2024.110314

Abstract

Purpose: To compare patient discomfort and immobilisation performance of open-face and closed immobilization masks in cranial radiotherapy.

Material and methods: This was a single-center randomized self-controlled clinical trial. At CT simulation, an open-face and closed mask was made for each patient and treatment plans with identical dose prescription were generated for each mask. Patients were randomised to start treatment with an open-face or closed mask. Masks were switched halfway through the treatment course; every patient was their own control. Patients self-reported discomfort, anxiety and pain using the visual analogue scale (VAS). Inter- and intrafraction set-up variability was measured with planar kV imaging and a surface guided radiotherapy (SGRT) system for the open-face masks.

Results: 30 patients with primary or metastatic brain tumors were randomized - 29 completed radiotherapy to a median total dose of 54 Gy (range 30-60 Gy). Mean discomfort VAS score was significantly lower with open-face masks (0.5, standard deviation 1.0) vs. closed masks (3.3, standard deviation 2.9), P < 0.0001. Anxiety and pain VAS scores were significantly lower with open-face masks (P < 0.0001). Closed masks caused more discomfort in infraorbital (P < 0.001) and maxillary (P = 0.02) areas. Two patients and 27 patients preferred closed or open-face masks, respectively. Interfraction longitudinal shifts and roll and yaw rotations were significantly smaller and lateral shifts were significantly larger with closed masks in combination with the laser system (P < 0.05) compared to open masks in combination with a SGRT system. Intrafraction variability did not differ between the masks.

Conclusions: Open-face masks are associated with decreased patient discomfort without compromising patient positioning and immobilisation accuracy.

Keywords: Cranial radiotherapy; Discomfort; Interfraction variability; Intrafraction variability; Open-face mask; Surface guided radiotherapy.