The primary purpose of this study is to explore the significance of analgesic treatment for radiation-induced oral mucositis pain in patients with nasopharyngeal carcinoma during radiotherapy, and to compare the analgesic effect of morphine controlled-release tablets with that of fentanyl transdermal patch. Half of participants will receive morphine controlled-release tablets,while the other half will receive fentanyl transdermal patch.

Morphine controlled-release tablets and fentanyl transdermal patch each relieve radiation-induced oral mucositis pain in patients with nasopharyngeal carcinoma. But they do so by different mechanisms and in different effects.

Morphine is a classic strong analgesic, which has been widely used in patients with advanced cancer pain. It has achieved satisfactory results in pain control, sleep improvement and quality of life. Oral morphine has been regarded as the standard treatment for moderate and severe cancer pain.

Fentanyl transdermal patch is a system device for transdermal delivery of drugs. It is compressed on a film containing fentanyl memory. The film can continuously release fentanyl into the blood circulation and maintain stable for more than 72 hours. It is not affected by gastrointestinal PH or food, and it has no hepatic frst-pass effect, with a bioavailability of up to 92%.

This study will test the efficacy and safety of morphine controlled-release tablets compared to fentanyl transdermal patch in the treatment of pain in patients with radiation-induced oral mucositis.

Inclusion Criteria:

• Patients were pathologically newly diagnosed with nasopharyngeal carcinoma and had no previous history of other tumors
• According to the treatment strategies of doctors, patients need to receive radiotherapy with or without chemotherapy (for example, neoadjuvant chemotherapy, concurrent chemotherapy, adjuvant chemotherapy) or targeted therapy
• Never use a opioid before treatment
• Hematology: WBC≥4.0×109/L, ANC≥1.5×109/L, PLT≥100×109/L,Hb≥90g/L.
• Participants with the ability to assess the pain level
• Willingness to return to enrolling institution for follow-up

Exclusion Criteria:

• Patients do not conform to the inclusion criteria
• Known allergy to fentanyl, morphine, or any known component of the drug formulation
• Refuse to use of opioid drugs
• Nasopharyngeal patients with mental illness
• Current untreated or unresolved oral candidiasis or oral HSV infection
• 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
• Pregnant or Nursing women
• Men or women of childbearing potential who are unwilling to employ adequate contraception
• Other contraindications or unsuitable conditions for radiotherapy