Effects of CKI for Oral Mucositis Caused by Radiotherapy for Head and Neck Cancer

Inclusion Criteria:

1. Patients are pathologically diagnosed as stage III or stage Ⅳ squamous cell carcinoma of head and neck cancer (including nasopharyngeal carcinoma)and are in accordance with the diagnostic criteria of radiotherapy induced mucositis/ stomatitis;
2. Patients have no prior history of radiotherapy, and grade III oropharyngeal mucositis occured after the first radiotherapy;
3. Patients have no stomatological diseases such as ulcer, edema and exudation in the oropharyngeal mucosa before radiotherapy;
4. Eastern Cooperative Oncology Group (ECOG) performance Score is 0 or 1;
5. The function of each organ is basically normal, including: hemoglobins ≥ 9g/dL, platelets ≥ 80×10\^9/L, leukocytes ≥ 3×10\^9/L, liver function within 3 times the upper normal limit, creatinine clearance ≥ 60mL/min;
6. Patients aged between 18 and 75 years;
7. Patients have a life expectancy of at least 6 months;
8. Patients have fully understood the study and signed the informed consent voluntarily prior to any related procedures of the study.

Exclusion Criteria:

1. Patients who have received CoKS or systemic antibiotic treatment within 2 weeks before treatment;
2. Patients who have a history of head or neck surgery (except biopsy);
3. Female patients who are pregnant or breast feeding or female of pregnancy potential with a positive pregnancy test before treatment;
4. Patients with serious or uncontrolled organic diseases or infections, such as decompensate cardiac function failure, pulmonary function failure, liver function failure, renal function failure, causing unability to tolerate radiotherapy;
5. Patients who have radiotherapy contraindications;
6. Patients who are allergic to the study medications or quinolones;
7. Patients have serious psychological or psychiatric disorders, drug abuse or alcohol dependence in the past;
8. Patients are currently participating in another clinical study or have participated in another clinical trial in the past 30 days;
9. The investigator believes that it is not appropriate to participate in this trial.