A Phase II Investigation of Contralateral Arytenoid Sparing IMRT for T1a and T2a Larynx Cancer With Detailed Analysis of Post-treatment Laryngeal Function

Parallel opposed portal external beam radiation is the standard nonsurgical treatment for T1-2N0 glottic cancer. This technique involves treatment of the entire larynx for tumors that are small and limited. Although technological advances now allow radiation oncologists selectively to target and avoid adjacent sub-portions of any organ, these tools have not been applied T1-2N0 glottic cancer due to the perceived low toxicity of standard therapy. However, radiotherapy for early glottic cancer is not without functional side effects and it is not known whether post-treatment function after whole larynx radiation is superior to a more targeted surgical approach.

This is a phase II study to treat unilateral glottic cancer (Stage T1a and T2aN0) with intensity modulated radiation therapy (IMRT). In view of the anticipated small volume of disease at presentation and need to limit the potential for a "marginal miss", treatment will include the entire involved vocal fold, anterior commissure, and the anterior 1/3 of the contralateral vocal fold thus sparing the contralateral arytenoid cartilage and musculature ("contralateral arytenoid sparing IMRT"). In addition, we propose to perform sophisticated objective and patient reported measures regarding speech outcomes for two years after the completion of therapy at specified intervals, to better gain an understanding of the effects of therapy. Our findings will have the potential to dramatically advance the field of early larynx cancer therapy by demonstrating the efficacy of limiting the volume of uninvolved larynx that receives radiation and comprehensively assessing the functional outcomes of said therapy.