Prophylactic training for the prevention of radiotherapy-induced trismus - a randomised study

Background. Radiotherapy-induced trismus (RTIT) is a debilitating condition without any proven effective treatment. This study investigates the effectiveness of prophylactic training to prevent RTIT during and up to 12 months after completed RT in patients with head and neck cancer (HNC), also investigating the incidence of RTIT. Methods. Sixty-six consecutive patients from two RT clinics in Sweden were randomised into one of two groups: training with TheraBite (R) Jaw Motion Rehabilitation System T or a control group. Maximum interincisal openings (MIO) were recorded at baseline and once a week during treatment, three, six and 12 months after completed RT. Training frequency was recorded by patients in a log book. Results. There were no significant differences in MIO between the intervention and control groups at any of the measurement points. Patients in both groups maintained their normal variation in MIO at 12 months after completed RT. A small group of patients in the control group had a 17% mean decrease in MIO by week 6 compared to baseline and improved their MIO by using the training programme. There was a significant mean difference in MIO from baseline to week 6 (3 mm, p = 0.018), and month 6 (2.7 mm, p = 0.040), for patients receiving 3D conformal radiotherapy. There was a significant difference in MIO between patients treated with RT and concurrent chemotherapy compared to patients with RT only at 12 months (p = 0.033). Conclusions. Patients with HNC undergoing high dose RT do not need to be burdened with an intense prophylactic training programme during RT and up to 12 months after completed RT. MIO measurements during RT and up to 12 months after completed RT are recommended to identify a small risk group who are an exception and may need a training programme.