The treatment of choice for stage I cancer larynx is-
Radical surgery
Chemotherapy
Radiotherapy
Surgery followed by radiotherapy
Friends remember 2 very important concepts regarding laryngeal Ca:

If the site of larynx caner viz supra glottis, glottis or subglottis is not mentioned, the cancer should be considered glottic (since it is the M/C variety)
Generally stage I, II, III, IV means stage T1 , T2 , T3 , T4 respectively.

According to Dhingra

Radiotherapy is the treatment of choice for all stage I cancers of larynx, which neither impair mobility nor invade cartilage or cervical nodes. 
The greatest advantage of radiotherapy over surgery in Ca larynx glottic cancer is - preservation of voice.