Comparing Closed Face Masks vs Surface Guided Radiation Therapy for Head and Neck Radiotherapy

Once eligibility has been confirmed and upon randomization, patients will begin treatment either with an immobilization mask (A) or no mask (B). One individual immobilization mask and AccuForm cushion will be fabricated for every single patient. All positioning setup information used for subsequent treatment sessions will be documented. One simulation CT/MRI will be acquired and one treatment plan for each setup. After image acquisition, the mask will be removed and stored for treatment. After the simulation, the patients will be asked to fill out a questionnaire evaluating their comfort/anxiety/pain in regards to the setup as a baseline assessment. The patients will be treated with 6 MV from a linear accelerator (Truebeam, Varian Medical Systems, Palo Alto, CA). Dose prescription and treatment planning objectives of the individual patient will be defined by the standard treatment protocol depending on the patient's disease and treatment intention. Before each treatment session, the patient will be positioned on the treatment couch with the designated immobilization material. Conebeam-CT (CBCT) images will be acquired followed by automatic/manual setup correction compared to simulation CT/MRI; a CBCT image will be acquired after the treatment session once a week and at the first three fractions with mask and no mask. The CBCT procedure is a part of the standard treatment protocol for head-and-neck irradiation. Data on CBCT imaging in the form of translational and rotational shifts will be used to measure and compare setup uncertainties (inter-fraction and intra-fraction accuracy) between the two arms. In the no mask arm, Align RT® (Vision RT Ltd., UK) an SGRT system will be used in addition to CBCT imaging, to evaluate translational and rotational motions during treatment and for initial set up and also Gate during treatment. The SGRT system will not be used in patients with immobilization masks on. On the first day of treatment and weekly thereafter (immediately after treatment), the patients will be asked to fill out the same questionnaire as in Simulation for a comfort/anxiety/pain evaluation. As standard practice, patients typically receive another CT simulation during the second half of their treatment, to allow for adjustments to their radiation plan. This is typically due to factors such as weight loss, swelling, tumour or anatomical changes. If necessary, a new mask is also created to account for such changes. This workflow will apply to this study and participants. At the very last treatment session, they will answer the question on their mask or no mask preference.

• Setup uncertainties [Срок оценки: during treatment before every treatment fraction, 5-6 times per week up to 7 weeks]
• intra-fraction accuracy [Срок оценки: during treatment before every treatment fraction, 5-6 times per week up to 7 weeks]
• Serious adverse events [Срок оценки: continuously during treatment up to 7 weeks]
• Device Deficiencies of the surface guidance system [Срок оценки: continuously during treatment up to 7 weeks]