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

Figures & data

Table I. Patient characteristics (n = 66).

Variables	Intervention group (n = 33)	Control group (n = 33)	p-value
Gender			p = 0.76
Male	27	26
Female	6	7
Age (mean, SD, range)	59.3, 10.7, 38–84	60.2, 11.1, 19–77	p = 0.74
Tumour site
Base of Tongue	5	5
Tongue	4	3
Nasal cavity	3	1
Floor of mouth	2	3
Parotid gland	8	4
Tonsil	10	12
Oropharynx/hypoparynx	1	1
Larynx	0	1
Lymph, secondary tumour	0	3
Tumour size			p = 0.83
T1	3	6
T2	15	12
T3	4	3
T4	4	5
Missing data	7	7
External beam Radiotherapy (RT)
3D Conformal Radiotherapy (3D-CRT)	16	19
Intensity-Modulated Radiotherapy	17	14
(IMRT)
Concomitant Chemotherapy*	17	18
No Chemotherapy	16	15
Surgery
Surgery before RT	11	10
Planned Surgery after RT	3	3
Unplanned Surgery after RT	2	1
No Surgery	18	19
RT dose in Gy			p = 0.79
< 50**	2	4
50–59	3	2
60–69	28	27

*Chemotherapy: Cisplatin 50 mg once a week.

**Lowest dose = 30 Gy.

Figure 1. Flow chart over study participation during and after RT.

Table II. Frequency of training from study start until 6 and12 months after completed radiotherapy (RT) and percent mean change in maximum interincisal opening (MIO) from baseline to 12 months after completed RT (n = 66).

Training frequency at 6/12 months	Intervention group (n = 33)		Control group/Intervention^a (n = 4)		Control group (unsystematic stretching) (n = 29)
Patients who completed 12 months of the study (n = 42)
	% change in MIO		% change in MIO		change in MIO
	6/12 months	at 12 month	6/12 months	at 12 months	6/12 months	at 12 months
5 times a day	3/2	−20.0^b	1/1	−3.7	1/1	+ 2.3
3–4 times a day	18/6	−4.3	2/1	−14.6	1/1	+ 17.9
1–2 times a day	3/7	+ 3.0	0/0		5/4	+ 4.4
1–5 times a week	0/4	−8.2	0/0		2/2	+ 2.2
No training	0/4	+ 17.7^c	0/0		10/9	+ 1.7
Missing data	0/0		0/0		0/0
	% change in MIO		% change in MIO		% change in MIO
Dropouts (n = 24)^d	6/12 months	up to dropout	6/12 months	up to dropout	6/12 months	up to dropout
5 times a day	0/0		0/0		0/0
3–4 times a day	6/6	−2.6	1/2	−4.9	0/0
1–2 times a day	2/2	–	0/0		0/1	0.0
1–5 times a week	0/1	−10.6	0/0		2/2	−8.9
No training	0/0		0/0		6/7^e	−1.6
Missing data	1/1	–	0/0		2/2	–

^aPatients were randomised to the control group but changed to the intervention group after a 15% decrease in MIO.

^b1 patient had a 20% decrease in MIO at 12 months due to residual cancer.

^cThese 4 patients had trained 2–3 times daily up to 6 months.

^dTraining data from the patients who dropped out during the study.

^e1 patient declined a training program despite a 15% decrease in MIO.

Figure 2. Mean change in MIO (%) from baseline, during RT and up to 12 months after completed RT. The lower number of patients weeks 6 and 7 is due to dose differences resulting in shorter time-period in external beam radiotherapy (see Figure 1 for details).

Figure 3. Mean change in MIO (%) from baseline, during RT and up to 12 months after completed RT. Patients with MIO decrease > 15%, who were offered training, is shown as a separate group. The lower number of patients weeks 6 and 7 is due to dose differences resulting in shorter time-period in external beam radiotherapy (see Figure 1 for details).

Figure 4. Mean change in MIO (%) from baseline, during RT and up to 12 months after completed RT in patients with 3D-CRT or IMRT. 3D conformal radiotherapy (3D-CRT) compared to baseline at 12 months:p = 0.22; *3D conformal radiotherapy (3D-CRT) compared to baseline at 6 weeks: p = 0.018; **3D conformal radiotherapy (3D-CRT) compared to baseline at 6 months: p = 0.040; ***3D conformal radiotherapy (3D-CRT) compared to IMRT at 6 months: p = 0.065; ****3D conformal radiotherapy (3D-CRT) compared to IMRT at 12 months: p = 0.084.