Dysphagia in head and neck cancer patients following intensity modulated radiotherapy (IMRT)

Radiation Oncology

Table 4 Median doses (median of the median dose) to the swallowing structures in all patients and comparison to reported series

Swallowing structures		Current study		Feng et al 2007[21]		Levendag et al* 2007[7]
		Median	Range	Median	Range	Median	Range
PCs	Volume (cc)	20	11-32	NA	NA	NA	NA
	Dose (Gy)	59	39-66	64	51-72	48	6.0-73.0
scm	Volume (cc)	12	6-21	NA	NA	NA	NA
	Dose (Gy)	59.4	24-69	68	57-74	51	22.0-73.0
mcm	Volume (cc)	3.6	1.5-9	NA	NA	NA	NA
	Dose (Gy)	59	37.0-71.5	64	53-75	48	11.0-72.0
icm	Volume (cc)	3.7	0.9-7	NA	NA	NA	NA
	Dose (Gy)	53	29-73	51	30-70	32	6.0-73.0
GSL	Volume (cc)	15.3	6.4-23	NA	NA	NA	NA
	Dose (Gy)	53	28-70	55	22-72	NA	NA
eim	Volume (cc)	5.4	0.7-44	NA	NA	NA	NA
	Dose (Gy)	39	16.0-67.8	44	15-66	18	3.0-64.0

* The results are not entirely comparable with the study of Levendag et al [7], as there is a difference in the delineation of muscular structures. In Levendag et al. the anterior part of scm and mcm were not delineated and eim was defined as the proximal 1 cm of the esophageal inlet, regardless of the caudal-most extent of the low neck target volumes.
Abbreviations: PCs: pharyngeal constrictor muscles, scm: superior constrictor muscle, mcm: middle constrictor muscle, icm: inferior constrictor muscle, GSL: glottic and supraglottic larynx, eim: muscular compartment of the esophagus inlet, NA: not assessed

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