Head and neck cancer is the most common tumor type, the sixth leading cancer by incidence worldwide and the eighth by mortality, which radiation therapy is the preferred and effective treatment (1). However, due to the influence of the tumor and tumor treatment, patients with head and neck cancer are mostly becoming a malnutrition group. Malnutrition is caused by a lack of nutrient intake or nutritional metabolism of damage to the nutrition state of disorder. The predominant symptoms are progressive emaciation, weight loss or edema. When hypoalbuminemia are serious, they can cause multiple organ damage. The malnutrition incidence of patients depends on tumor location, type and disease stages. The malnutrition prevalence rate of head-neck cancer patients is as high as 74.2%. Patients with malnutrition have numerous effect factors, predominantly including the tumor caused by the body's metabolic abnormalities, antitumor treatment side effects and tumor diagnosis of psychological social factors.

Radiation therapy is used to cure or as palliative treatment for patients with head and neck cancer (2). Due to the toxic effects of radiation to the tumor cells and normal tissue cells, including blood cells, the hair follicle and cells on the surface of the digestive tract, are sensitive to radiation damage. During treatment, the patients also suffer from nausea and vomiting, anorexia, full bilge, diarrhea, mucositis, oral inflammation, pain and other symptoms, This symptoms influence the patient's interest in food, food preparation and feeding capacity. Therefore the patients lack of a sufficient nutrient intake, causing malnutrition (3). Ottery (4) believed that ~20% of the cancer patients did not succumb to the tumor itself, but the consequences of malnutrition. To better fit the antitumor treatment and improve the quality of life for the patients, in the past twenty years, the issue of ‘tumor patient nutritional support’ has been performed in numerous studies. The American society for parenteral enteral nutrition and the France cooperation organization based on the collecting previous evaluation research results put forward several opinions for the principles and methods on nutritional support. Clarifying nutritional assessment must be performed for all patients, particularly cancer patients suffering from malnutrition during therapy. These important principles emphasized that the evaluation of nutritional status as a regular assessment must be performed as early as possible. Additionally, when patients require nutritional interventions, these must be initiated as early as possible. The nutrition intervention project implementation must become part of the whole treatment. This requires more staff to cooperate in the various fields, including doctors, nurses, dietitians and pharmacists. There should be close associations with the professional team in the lab and the management department (2).

Oral nutritional support includes food-based interventions, the use of snacks to supplement intake from meals and the use of oral nutritional supplements (5). When a stable disease or complete remission is achieved, the nutritional status can impact cancer recurrence. Dietary habits can also prevent certain cancer types in healthy individuals (6). The advantage in prostate cancer is less obvious (7). Suzuki et al (8) reviewed an in-depth description of cancer-related malnutrition pathophysiology. The well-being of the patient may largely be influenced by a good nutritional status (9). However, measuring quality of life remains controversial (10). It is not appropriate to focus on feeding without anticipating changes in physiological and psychosocial behavior (11). On the contrary, optimal nutrition in combination with systemic antiinflammatory treatment and erythropoietin improves the survival of underweight malignant patients (12,13). Additionally, the number of patients receiving intensive multimodality therapy is likely to increase (14).

Involuntary weight loss for head and neck cancer of >5% in 1 month, or >1–2% per week is a reliable indicator of malnourishment, which has been associated with hospitalization and treatment interruptions (14–17). The present study performed a prospective, randomized controlled trial in patients with head and neck cancer referred for RT, which was designed to investigate whether dietary counseling or oral nutrition supplements preRT and postRT affected nutritional status. Furthermore, the impact of nutritional intervention may have predefined outcomes, (nutritional status, calorie intake and energy expenditure) during treatment.

Head and neck malignant tumors can occur in numerous locations. The most common malignant tumor types are thyroid cancer, nasopharyngeal carcinoma (NPC) and salivary gland tumors (1). The most common cancer types were the oral cavity cancer, including the tongue, buccal mucosa, gums, mouth floor, hard palate and the soft palate, and tonsil, laryngeal cancer, malignant lymphoma, neck metastatic carcinoma of unknown primary tumor (1). The incidence of head and neck malignant cancer are different in different countries, regions, nationalities, races and times (2). Men are more prone to morbidity than women and the highest risk is 40–60-years-old. After 60 years the morbidity gradually declines. A total of 82.4% patients were male in this group, 60.0% of patients were 37–60-years-old, the average age was 59 and the overall morbidity was similar to a basic situation. Radiation therapy is used to cure or as palliative treatment for head and neck tumors. Due to the radiation, the tumor cells and normal tissue cells have toxic effects; all rapidly dividing cells, including blood cells, hair follicle and cells on the surface of the digestive tract, are sensitive to radiation damage (23). Oral mucosal surface is very sensitive to RT. After RT, throat ulcers, difficulty swallowing, dry mouth, loss of appetite, lack of sense of taste and other symptoms will occur in patients with head and neck cancer. The radiation reaction is also prone to cause damage of the salivary glands, reduce salivation, saliva become viscous, and the patient can have chewing and swallowing difficulties. Radiation damage may improve over months and some may never return to the level prior to treatment (24). During the course of treatment, patients also appear nausea and vomiting, anorexic, with full bilge, diarrhea, catarrh, stomatitis, pain and other symptoms (25). The patient's interest in food and food preparation, and the ability to eat are influenced, which reduces the nutrient intake, resulting in malnutrition.

The present study showed that the nutritional status of the patients gradually declined during treatment. The symptoms may be caused during RT, and radiation adverse effects in patients are gradually strengthened and clinical symptoms appeared. When the SGA method was used to assess the patient's nutritional status, it assisted medical personnel to accurately evaluate and compare the nutritional state of patients to find the deterioration of nutritional status, so the necessary support measures as administered as early as possible (26). During RT, while in the care of the patients with head and neck cancer, we gave early nursing nutrition intervention, it can make the patients better cooperate to complete radiotherapy treatment and make the radiation effect achieve the best state.

Based on a review of the available literature, patients with head and neck cancer undergoing RT required nutrition intervention at regular intervals during treatment (14). Regular dietary counseling during treatment has also been recommended, as it has been associated with less weight loss during treatment (27). McQuellon et al (28) used megestrol acetate during treatment to stimulate appetite and may be of some benefit in certain circumstances.

In conclusion, the nutritional status of head and neck cancer patients during RT gradually declined and patients with good nutritional status gradually reduced. When providing nutritional intervention to the patients, the good nutritional status increased and the severe nutritional status decreased. Therefore, early intervention can improve curative effect for patients undergoing RT.