ESTRO 2024 - Abstract Book

S5622

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

1. Stock, M., Pasler, M., Birkfellner, W., Homolka, P., Poetter, R., & Georg, D. (2009). Image quality and stability of image guided radiotherapy (IGRT) devices: a comparative study. Radiotherapy and Oncology, 93(1), 1-7.

2. Liu, F., Cuevas, C., Moss, A. A., Kolokythas, O., Dubinsky, T. J., & Kinahan, P. E. (2008). Gas bubble motion artifact in MDCT. American Journal of Roentgenology, 190(2), 294-299.

3. Shah, R., Khoram, R., Lambert, J. W., Sun, Y., Wang, Z. J., Webb, E. M., & Yeh, B. M. (2018). Effect of gantry rotation speed and scan mode on peristalsis motion artifact frequency and severity at abdominal CT. Abdominal Radiology, 43, 2239-2245. 4. Sweeney, R. A., Seubert, B., Stark, S., Homann, V., Müller, G., Flentje, M., & Guckenberger, M. (2012). Accuracy and inter-observer variability of 3D versus 4D cone-beam CT based image-guidance in SBRT for lung tumors. Radiation Oncology, 7(1), 1-8. 5. Josipovic, M., Persson, G. F., Bangsgaard, J. P., Specht, L., & Aznar, M. C. (2016). Deep inspiration breath-hold radiotherapy for lung cancer: impact on image quality and registration uncertainty in cone beam CT image guidance. The British journal of radiology, 89(1068), 20160544.

2968

Digital Poster

Off with their heads! A comparison between four- & five-point immobilisation for thoracic patients

Rhianne Kelly, John Rodgers, Clare Triffitt

The Christie NHS Foundation Trust, Radiotherapy, Manchester, United Kingdom

Purpose/Objective:

Radical thoracic external beam radiotherapy delivery uses highly conformal techniques such as VMAT to deliver high radiation doses to tumours whilst sparing normal tissue to reduce treatment related toxicity.

As with the practice of most radiotherapy departments, the author’s department images thoracic patients daily prior to treatment employing CBCT to verify patient position. Immobilisation is fundamental for consistent and accurate radiotherapy and uses either a dedicated lung board or moulded thermoplastic mask. The mask currently in practice within the authors department moulds over the head, neck and shoulder. It is attached at five points to the treatment couch, or dedicated treatment board, and thus described colloquially as a five-point shell. An increasing number of patients immobilised using five-point shells struggle with the treatment experience due to claustrophobia and anxiety. The authors department wanted to investigate whether a shell that moulded and immobilised the neck and shoulders but left the head and face open, i.e. a four-point shell, would provide an improved experienced for thoracic patients whilst providing similar levels of accuracy during treatment set up. Both immobilisation devices were supplied by Qfix (Avondale, US) and are shown in Figure 1.