Radiation therapy alone vs surgery
For early-stage glottic laryngeal carcinomas surgery or RT have similar effectiveness. A number of systematic reviews of non-RCTs have shown endolaryngeal surgery (with or without laser) can provide similar voice and laryngeal function preservation and survival rates when compared to RT alone.rrr
Hypofractionation vs. standard fractionation
The ultimate goal in treating early glottic carcinoma is cure of the tumour, while preserving organ function, allowing the best voice quality possible, and without serious side effects. Dose per fraction and overall treatment time have been identified as factors that contribute to locoregional control.rr Numerous studies have shown a locoregional control advantage for hypofractionated radiation therapy schedules when treating early stage glottic carcinoma, as compared to standard 2Gy per fraction daily treatments without an increase in serious complications.rrrrr Therefore the use of hypofractionated protocols over conventional schedules is considered standard of care.
The Japanese RCT reported significantly improved local control with hypofractionated radiation therapy (56.25-63Gy in 2.25Gy fractions) compared with 60-66Gy in 2Gy fractions.r In this trial, 180 patients with T1 glottic cancer, treated from 1993 to 2001, were randomised to either conventional or hypofractionated schedules. The dose prescribed for each schedule was dependent on the size of the tumour (in the hypofractionated arm 56.25Gy was prescribed if the tumour was </=2/3rds in length of the ipsilateral or bilateral vocal cords, vs 63Gy if the tumour occupied >2/3rds of the vocal cord). The 5 year local control was 77% vs 92% in the conventional and hypofractionated arms, respectively (p<0.004).
The DAHANCA group also reported improvement in 5 year locoregional control with an accelerated fractionated schedule.r 1476 patients were randomised to either 5 or 6 fractions of radiation therapy per week with the same total dose. The total dose delivered was 66-68Gy in 33-34 fractions, except for well-differentiated T1 glottic tumours which were treated with 62Gy. Of these patients 47% had laryngeal cancer, and 29% of patients overall had Stage I disease. Individual figures for LRC for early stage glottic cancer were not reported, but overall LRC improved from 60 to 70% (p=0.0005) in favour of the 6 fraction per week arm. There was no significant difference in overall survival. Disease-specific survival was 73% vs 66% for six and five fractions, respectively (p=0.01).