This is a prospective study to determine the local control and quality-of-life outcomes of using SBRT for early-stage glottic larynx cancer.

SBRT treatment will be delivered to patients diagnosed with stage I-II glottic larynx cancer twice per week for 5 fractions (42.5 Gy cohort, low-risk) or daily for 16 fractions (58.08 Gy cohort, moderate-risk).

Low-risk is defined by:

• Planning target volume (PTV) less than 10 cc, AND
• No reported smoking within 1 month from registration

Moderate-risk is defined by:

• Planning target volume (PTV) greater than or equal to 10 cc, OR
• Smoking within 1 month from registration (no more than 1 pack per day)

Inclusion Criteria:

1. Pathologically-proven diagnosis of squamous cell carcinoma in situ, squamous cell carcinoma or squamous cell variants (sarcomatoid, verrucous, basaloid, and papillary subtypes) involving the glottic larynx.

2. Clinical stage I-II (American Joint Committee on Cancer AJCC, 7th edition) with direct laryngoscopy showing no evidence of greater than stage II true glottic larynx cancer and PET/CT or CT neck showing no evidence of regional disease.

3. Age ≥ 18 years.

4. ECOG Performance Status 0-2

5. Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 90 days following completion of therapy. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.

   5.1 A female of child-bearing potential is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:

   • Has not undergone a hysterectomy or bilateral oophorectomy; or
   • Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).

6. Negative serum or urine pregnancy test within 2 weeks before registration for women of childbearing potential.

7. Ability to understand and the willingness to sign a written informed consent.

8. Patients with cognitive impairment or other limited decision making capacity with the ability to understand and willingly sign written informed consent or have the consent signed by a designated legally authorized representative (LAR)

Exclusion Criteria:

1. AJCC stage III or stage IV larynx cancer
2. Involvement of the arytenoid cartilage beyond the vocal process.
3. Prior chemotherapy for treatment of the targeted larynx lesion
4. Synchronous primaries in the head and neck
5. Prior radiotherapy to the region of the study cancer that would result in overlap of radiation fields.
6. Subjects smoking in excess of 1 pack of cigarettes per day.
7. Subjects may not be receiving any other investigational agents.
8. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
9. Subjects must not be pregnant or nursing due to the potential for congenital abnormalities and the potential of this regimen to harm nursing infants.

Early stage larynx cancer patients receiving SBRT; additional details in participant flow

From baseline to 36M post treatment

Adverse events were not collected separately based on dose. The AEs were evaluated with all patients together as one group.