Table 1.

T staging of glottic carcinoma

T1	Tumour limited to vocal cord(s) with normal mobility
T1a	Tumour limited to one vocal cord
T1b	Tumour involves both vocal cords
T2	Tumour extends to supra- and/or subglottic larynx or region outside the supraglottis (with or without impaired vocal cord mobility)
T3	Tumour limited to the larynx with vocal cord fixation and/or invades paraglottic space, and/or minor thyroid cartilage erosion (e.g. inner cortex)
T4a	Tumour involves tissues beyond the larynx and/or laryngeal cartilage (e.g. trachea, deep extrinsic tongue muscles, strap muscles, thyroid or oesophagus)
T4b	Tumour invades prevertebral space, encases carotid artery or invades mediastinal structures