Effect of arytenoid sparing during radiation therapy of early stage glottic carcinoma

To retrospectively evaluate the effect of arytenoid shielding on local control and complications in the treatment of early stage glottic carcinomas.

The analysis concerns 71 patients treated with megavoltage photons for stages Tis, T1 and T2 glottic carcinomas. In 31 patients the entire larynx was treated at 2 Gy/day to full dose (group 1, mean field area 41.5 cm2) and in 40 patients a posterior block was placed after a median dose of 54 Gy to protect the arytenoid cartilage (group 2, mean field area 38 cm2). The decision to shield 10-15 mm of the posterior aspect of the treatment volume was based on the presence or absence of involvement of the posterior third of the vocal cords. Median total dose was 70 Gy in both groups.

RTOG grade 2 and 3 acute laryngeal complications were observed in 77% and 62.5% of patients in groups 1 and 2, respectively (P = 0.25). The rate of grade 2-3 late laryngeal complications (mostly arytenoid edema) was similar in the two groups (13.6% vs 20%, P = 0.83). Actuarial local control at 5 years was also similar in the two groups (T1: 85% vs 96.6%, P = 0.13 and T2: 82% vs 87.5%, P = 0.86).

No objective differences could be shown in terms of acute or late laryngeal complications or in terms of local control related to the use of arytenoid shielding. As severe complications are rare and local control is very satisfactory using standard techniques, it is difficult to attribute any advantage to the use of arytenoid blocking.