A randomized controlled trial comparing customized versus standard headrests for head and neck radiotherapy immobilization in terms of set-up errors, patient comfort and staff satisfaction (ICORG 08-09) C. Howlin a, * , E. O'Shea a , M. Dunne a , L. Mullaney a , M. McGarry a , A. Clayton-Lea b , M. Finn a , P. Carter b , B. Garret b , P. Thirion b a Clinical Trial Resource Unit, St. Luke's Hospital, St. Luke's Radiation Oncology Centre, Highfield Road, Rathgar, Dublin 6, Ireland b Radiotherapy Department, St. Luke's Hospital, St. Luke's Radiation Oncology Centre, Highfield Road, Rathgar, Dublin 6, Ireland article info Article history: Received 27 March 2014 Received in revised form 3 June 2014 Accepted 28 July 2014 Available online 22 August 2014 Keywords: Head and neck radiotherapy Immobilization Headrests Set-up errors abstract Purpose: To recommend a specific headrest, customized or standard, for head and neck radiotherapy patients in our institution based primarily on an evaluation of set-up accuracy, taking into account a comparison of patient comfort, staff and patient satisfaction, and resource implications. Methods and materials: Between 2008 and 2009, 40 head and neck patients were randomized to either a standard (Arm A, n ¼ 21) or customized (Arm B, n ¼ 19) headrest, and immobilized with a customized thermoplastic mask. Set-up accuracy was assessed using electronic portal images (EPI). Random and systematic set-up errors for each arm were determined from 668 EPIs, which were analyzed by one Radiation Therapist. Patient comfort was assessed using a visual analogue scale (VAS) and staff satis- faction was measured using an in-house questionnaire. Resource implications were also evaluated. Results: The difference in set-up errors between arms was not significant in any direction. However, in this study the standard headrest (SH) arm performed well, with set-up errors comparative to customized headrests (CHs) in previous studies. CHs require regular monitoring and 47% were re-vacuumed making them more resource intensive. Patient comfort and staff satisfaction were comparable in both arms. Conclusion: The SH provided similar treatment accuracy and patient comfort compared with the CH. The large number of CHs that needed to be re-vacuumed undermines their reliability for radiotherapy schedules that extend beyond 34 days from the initial CT scan. Accordingly the CH was more resource intensive without improving the accuracy of positioning, thus the standard headrest is recommended for continued use at our institution. © 2014 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. Introduction Advances in head and neck (H&N) immobilization help to pro- vide the reproducibility required to deliver increasingly accurate radiotherapy treatments in tandem with technological advances. 1,2 This can be achieved through careful attention to immobilization and patient preparation which should help to reduce systematic and random errors, 3 and permits smaller planning target volume (PTV) margins. 4 Accordingly, it is imperative to ensure that immobilization techniques are measured and continually improved. 3 This is particularly relevant for Intensity Modulated Radiation (IMRT), where treatment precision becomes paramount due to the dosimetric impact of set-up variation in the presence of steep dose gradients. 4,5 For example as little as a 3 mm translational error in the AP direction can result in an increase of 41% in the minimum dose to the spinal cord and a decrease of 38% minimal dose to the target. 6 Customized thermoplastic masks are estab- lished as the minimum requirement for H&N radiotherapy. How- ever, more rigorous devices need to be developed before the full benefits of dose escalation can be realized. 2 According to the On Target guidance document, headrests that match the anatomy of the patient more closely will result in improved immobilization techniques. 3 Accordingly, some studies have demonstrated improved accuracy and reproducibility with * Corresponding author. St. Luke's Radiation Oncology Centre at St. James's Hospital, James's St., Dublin 8, Ireland. Tel.: þ353 1 4206974; fax: þ353 1 420 6990. E-mail address: howlinc@tcd.ie (C. Howlin). Contents lists available at ScienceDirect Radiography journal homepage: www.elsevier.com/locate/radi http://dx.doi.org/10.1016/j.radi.2014.07.009 1078-8174/© 2014 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. Radiography 21 (2015) 74e83