Please assess the completion status of the following clinical trial:

Trial Title: Acetylcysteine Rinse in Reducing Saliva Thickness and Mucositis in Patients With Head and Neck Cancer Undergoing Radiation Therapy

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: SUPPORTIVE_CARE
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE2
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Histological confirmation of tumor of the oral cavity, oropharynx, supraglottic larynx, or nasopharynx~* Receiving concurrent chemoradiotherapy/chemobiotherapy to a minimum dose equivalent to 60 Gy in 30 fractions in the adjuvant or definitive setting~* Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2~* Initiation of investigational agent =\< 3 days after initiation of radiotherapy~* Negative pregnancy test done =\< 7 days prior to registration, for women of childbearing potential only~* Ability to complete questionnaire(s) by themselves or with assistance~* Provide informed written consent~* Willing to return mail-in questionnaires during the observation phase of the study~Exclusion Criteria:~* Any of the following:~  * Pregnant women~ * Nursing women~ * Men or women of childbearing potential who are unwilling to employ adequate contraception~* Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens~* Immunocompromised patients and patients known to be human immunodeficiency virus (HIV) positive and currently receiving antiretroviral therapy; NOTE: patients known to be HIV positive, but without clinical evidence of an immunocompromised state, are eligible for this trial~* 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~* Receiving any other investigational agent which would be considered as a treatment for the primary neoplasm~* History of myocardial infarction =\< 6 months, or congestive heart failure requiring use of ongoing maintenance therapy for life-threatening ventricular arrhythmias~* Receipt of induction chemotherapy~* Previous receipt of head and neck irradiation~* Utilization of amifostine during radiotherapy~* Greater than or equal to grade 2 dry mouth prior to chemoradiotherapy or greater than or equal to grade 2 mucositis~* Previous intolerance/adverse effect/allergy to any component of the placebo or active agent~* History of Sjogren's, lupus or scleroderma

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Arm I (acetylcysteine) (Type: EXPERIMENTAL): Patients receive acetylcysteine oral rinse and gargle or swish for 60 seconds then spit 5 times per day beginning within 3 days of the initiation of radiotherapy to 14 days following completion of radiotherapy.
- Arm II (placebo) (Type: PLACEBO_COMPARATOR): Patients receive a placebo oral rinse and gargle or swish for 60 seconds and then spit 5 times per day beginning within 3 days of the initiation of radiotherapy to 14 days following completion of radiotherapy.

Based on this trial design, predict the completion outcome and termination type (if applicable).

Answer: outcome: complete