Swallowing sparing intensity modulated radiotherapy versus standard parotid sparing intensity-modulated radiotherapy for treatment of head and neck cancer: a randomized clinical trial

Figures & data

Table 1. Baseline characteristics of the two studied groups.

	SW-IMRT Group (n = 71)	ST-IMRT Group (n = 75)	p Value
Age (years)	49.6±11.7	52.6 ±13.4	0.160
Sex (male/female)	47/24	50/25	0.952
Performance status (0/1)	36/35	34/41	0.516
Primary site			0.254
Nasopharynx	24 (33.8%)	27 (36.0%)
Larynx	16 (22.5%)	27 (36.0%)
Oral cavity	16 (22.5%)	12 (16.0%)
Hypopharynx	8 (11.3%)	6 (8.0%)
Oropharynx	7 (9.9%)	3 (4.0%)
T classification			0.736
T1	6 (8.5%)	7 (9.3%)
T2	21 (29.6%)	26 (34.7%)
T3	33 (46.5%)	28 (37.3%)
T4	11 (15.5%)	14 (18.7%)
N classification			0.932
N0	23 (32.4%)	27 (36.0%)
N1	9 (12.7%)	7 (9.3%)
N2	35 (49.3%)	37 (49.3%)
N3	4 (5.6%)	4 (5.3%)
Stage			0.978
I	2 (2.8%)	1 (1.3%)
II	8 (11.3%)	8 (10.7%)
III	31 (43.7%)	35 (46.7%)
IV	30 (42.3%)	31 (41.3%)
Treatment			0.455
Adjuvant	10 (14.1%)	14 (18.7%)
Definitive	61 (85.9%)	61 (81.3%)

Data are expressed as mean ± SD, or number (%).

Figure 1. CONSORT diagram.

Table 2. The mean dose (in Gy) delivered to SWOARs in patients with nasopharyngeal, laryngeal, and hypopharyngeal carcinomas in the two studied groups.

	SW-IMRT Group	ST-IMRT Group	p Value
Nasopharyngeal	n = 22	n = 26
Base of tongue	40.7±7.2	55.7±7.3	<0.001
Inferior pharyngeal constrictor	51.9±5.3	56.4±6.4	0.012
Cricopharyngeus	51.7±4.4	54.7±6.5	0.081
Esophageal inlet	47.3±11.6	52.9±5.5	0.040
Cervical esophagus	43.6 ±9.0	45.3±5.4	0.466
Glottic larynx	45.8± 5.5	47.2± 6.1	0.410
Supraglottic larynx	48.8± 5.7	53.8±6.5	0.010
Laryngeal and hypopharyngeal	n = 22	n = 27
Base of tongue	43.7± 8.0	55.2± 6.7	<0.001
Superior pharyngeal constrictor	42.3±7.8	41.0 ±9.4	0.640

Data are expressed as mean±SD.

Table 3. Assessment of dysphagia in the two studied groups during treatment and up to one year after treatment.

Dysphagia	SW-IMRT	ST-IMRT	p Value
During treatment
G0	10 (14.1%)	7 (9.3%)	0.262
≥ G1	61 (85.9%)	68 (90.7%)
n	71	75
At 1 month
G0	32 (48.5%)	13 (20.3%)	0.001
≥ G1	34 (51.5%)	51 (79.7%)
n*	66	64
At 3 months
G0	35 (55.6%)	14 (23.7%)	<0.001
≥ G1	28 (44.4%)	45 (76.3%)
n	63	59
At 6 months
G0	38 (65.5%)	12 (22.2%)	<0.001
≥ G1	20 (34.5%)	42 (77.8%)
n	58	54
At 1 year
G0	28 (59.6%)	13 (30.2%)	0.006
≥ G1	19 (40.4%)	30 (69.8%)
n	47	43
Videofluoroscopy (DIGEST)
At 3 months
0–1	26 (76.5%)	8 (36.4%)	0.005
2–4	8 (23.5%)	14 (63.6%)
n	34	22
At 6 months
0–1	23 (82.1%)	9 (42.9%)	0.006
2–4	5 (17.9%)	12 (57.1%)
n	28	21
At > 1 year
0–1	10 (76.9%)	3 (30.0%)	0.04
2–4	3 (23.1%)	7 (70.0%)
n	13	10

*The numbers examined are those available at the time of examination after dropping those patients who died or developed recurrence or distant metastases.

Data are expressed as number (%).

Table 4. The relation between the development of ≥ G1 dysphagia at six months and dose to SWOARs in nasopharyngeal, laryngeal, and hypopharyngeal carcinomas in the two studied groups.

	No dysphagia	≥ G1 dysphagia	p Value
Nasopharyngeal	n = 14	n = 22
Base of tongue mean dose	44.1±10.3	52.0± 9.1	0.018
Base of tongue maximum dose	62.9± 6.2	68.7± 4.7	0.003
MPC mean dose	54.7±5.1	60.0± 6.4	0.013
MPC V55 (%)	45.2 (6.9–100.0)	100.0 (0.0–100.0)	0.014
MPC V60 (%)	18.4 (0.4–85.7)	84.9 (0.0–100.0)	0.004
MPC V65 (%)	0.0 (0.0–6.4)	6.3 (0.0–76.8)	0.003
IPC mean dose	51.8±4.3	56.4±6.6	0.027
IPC V55 (%)	22.4 (3.6–98.4)	91.2 (0.0–100.0)	0.012
IPC V60 (%)	1.9 (0.1–44.8)	34.6 (0.0–100.0)	0.027
IPC V65 (%)	0.0 (0.0–0.7)	0.0 (0.0–54.1)	0.484
Cricopharyngeus m. mean dose	51.7±3.8	55.6±6.1	0.047
Supraglottic larynx mean dose	48.9±5.3	54.4±6.4	0.012
Laryngeal and hypopharyngeal	n = 22	n = 15
Base of tongue mean dose	47.6± 9.2	54.7± 7.3	0.019

Data are presented as mean±SD, or median (range).

MPC: middle pharyngeal constrictor muscle, IPC: interior pharyngeal constrictor muscle, V40: volume receiving 40 Gy, V50: volume receiving 50 Gy, V55: volume receiving 55 Gy.