Introduction

The global incidence of oral cavity, pharynx, and larynx cancer is around 500,000 cases yearly, with an average yearly mortality rate of 270,000. Head and neck cancer accounts for approximately 4% of these malignancies (1). Except for skin cancer, these instances represent 5% of all cancer-related mortality, with about three-quarters attributable to oral cavity and pharynx malignancies and the remaining 1.4% attributable to laryngeal cancer (2).

Radiotherapy is one of the primary treatments that is sometimes used alone and sometimes in conjunction with other treatments (3). In situations of irradiation of the oral cavity and salivary glands, problems such as the death of taste bud cells, the diminution of salivary gland secretory function, oral mucositis, and peripheral neuropathy are unavoidable. These patients frequently feel dry mouth, altered taste perception, difficulty in opening the mouth (trismus), and difficulty in swallowing (dysphagia) (4).

Another problem is radiation-induced somatic nerve damage, which produces discomfort. 30-80% of patients with cancer endured discomfort. Pain in the oropharynx, face, or neck, or as a headache, is the initial clinical finding in these individuals (5).

The limited studies have been conducted based on patients’ complaints about the oral side effects of radiotherapy, and have only addressed a few oral side effects, and no study using this questionnaire has been conducted on the Iranian population. Therefore, the purpose of this study is to investigate the side effects of radiation therapy in patients with head and neck cancer according to the late effects of normal tissues - subjective objective management and analytic (LENT-SOMA) questionnaire.

Material and Methods

This work is descriptive-analytical research about 60 patients with head and neck malignancies referred to “Shafa Hospital” in Kerman before, during, and one to three months following radiation between 2018 and 2019.

The inclusion criteria of the present study was the presence of primary cancer in the head and neck region requiring radiation as primary or adjunctive therapy. The patient must be free of oral mucosa disorders and systemic conditions impacting saliva. Exclusion criteria include cancer recurrence in the investigated regions and individuals who have had a significant resection.

The LENT-SOMA questionnaire, which is regarded as a valid questionnaire in the field of oral diseases, has been utilized after recording the demographic information of each patient through interview and file review to verify diagnostic and treatment information (6,7).

The validity and reliability of the applied questionnaire has been established by Rabiei et al. (8). The final year student performed the Persian version of the LENT-SOMA questionnaire as a control for all patients prior to radiation treatment, during radiotherapy treatment (7 to 14 days from the start of radiotherapy) and one to three months after the conclusion of radiotherapy treatment. The goal of the study was first explained to each participant, and they were provided with the questionnaire if desired. In addition, all respondents were promised that the information they provided on the questionnaire would remain secret and would be studied solely from a statistical standpoint; the questionnaire was also anonymous (verbal consent). This project was approved by the Ethical Committee of Kerman University of Medical Sciences of the university with the code IR.KMU.REC.1399.488 (date: 17.08.2023).

Statistical Analysis

The data analysis was performed using chi-square, ANOVA, and SPSS 21 (IBM SPSS Statistics V21, SPSS Inc., Chicago, Ill., USA).

Results

This research investigated sixty patients. Thirty patients completed the questionnaire before and during therapy, and rest of them completed the questionnaire before, during, and one and three months following treatment. The age ranges of the patients was 81 to 25 years, with an average age of 59.49.3 years (Table 1).

The minimum and maximum radiation dosages were 700 and 6,900 cGy, respectively. The most prevalent site of involvement was the larynx in 14 individuals (23.3%), followed by the nasopharynx in 9 people (15%), the hypopharynx in 6 people (10%), the tonsil in 4 people (6.7%), the oropharynx in 6 people (10%), and the oropharynx in 7 people (11.7%) (Table 2).

Before beginning radiation therapy, all patients described their discomfort as bearable. Most locations had a more severe kinds of pain during and one month after treatment. One month following treatment, the most extreme pain or type of sciatica was reported in the majority of affected locations.

One month following therapy, mouth discomfort (16.6%), ear ache (63.3%), jaw pain (6.6%), and sore throat (6.6%) were regarded as excruciatingly painful. After three months of therapy, pain severity decreased in all locations (Table 2).

50% of ear discomfort, 53.3% of throat pain, 40% of jaw pain, and 16.6% of mouth pain were unbearably unpleasant throughout therapy. Three months following radiation, 98 % of patients reported frequent discomfort and four patients reported terrible pain in these locations (Table 3).

A month after radiation therapy, 89% of patients with a sore throat, 81.2% of patients with mouth pain, 82.5% of patients with ear discomfort, 79.2% with jaw pain, and 61.3% of patients with tooth pain utilized housing constantly.

By separating the analyzed periods within one month following treatment, the severity of discomfort, the frequency of pain complaints, and the frequency of taking medication to ease pain in the throat, ear, jaw, and mouth were considerably higher than at other times (p=0.001). Additionally, the degree of toothache was greater one month after therapy than on other occasions.

After one and three months of therapy, 60% and 80% of patients, respectively, exhibited significant xerostomia.

Before beginning therapy, 73.3% of patients had no difficulty chewing. The data analysis about patients conducted over the course of one month revealed that 36.6% had trouble chewing hard foods, and 16.6% had difficulty eating soft foods. 98% of patients could not swallow soft meals one month following therapy, while 93,4 % were unable to consume beverages at this time. However, three months following therapy, a more significant proportion of patients were able to chew soft meals with more ease (Table 4).

This study revealed that, after adjusting for age and gender, changes in the sensation of taste, dysphagia, the frequency of experiencing dry mouth, the severity of xerostomia, and its influence on chewing different types of food were substantially greater one month after therapy than at previous periods (p=0.001).

One month after radiotherapy, the consequences of irradiation were identified in some variables. The pain in the ear and jaw exhibited a statistically significant association with the radiation dosage (p=0.001). Also, the present findings showed an increase in the rate of discomfort with age and gender (p=0.001).

Discussion

This study investigated the oral side effects of radiation in patients before, during, and one month and three months following treatment according to the LENT-SOMA questionnaire.

Compared to the research work by Rabiei et al. (8), the present study reveals that 60% of patients comprehend their pain experience since initiating therapy. In other investigations, pain has been identified as the most common side effect of radiation, with incidence rates ranging from 30% to 80% (9). Oral mucositis pain is the most prevalent symptom affecting mouth and jaw function (10).

In the study conducted by Elting et al. (11), the severity of mucositis and associated discomfort lessened throughout the sixth month (12).

The majority of patients related their pain to the tumor and/or cancer treatment. Whereas 59% reported their pain to be less severe than they expected, 29% were not satisfied with their level of pain despite pain management during cancer therapy. The most common neuropathic pain descriptors chosen were aching (20%) and burning (27%); nociceptive words chosen were dull (22%), sore (32%), tender (35%), and throbbing (23%), and affective/evaluative descriptors were tiring (25%) and annoying (41%).

Rose-Ped et al. (13) showed that painful sore throat takes place the most frequently (20%), followed by mouth sores and pain (18%), and dry mouth (14%) (13%).

One and three months following therapy, 60% and 80% of patients, respectively, exhibited significant xerostomia, which is less than the finding by Rabiei et al. (8).

Dirix  et al. (14) research showed that dry mouth improved three to four weeks following radiation.

Three months following therapy, the process of restoring the sense of taste is nearing completion. Consistent with the observations of Yamashita et al. (15), Rabiei et al. (8), and Chen et al. (16). In the research by Shenoy et al. (7), some improvement of the sensation of taste occurred between 20 and 60 days following the conclusion of therapy, and it was totally restored four months later.

Trismus is common following radiation. In the research by Rabiei et al. (8), 9.8% of patients had trismus of the head and neck muscles, which persisted after three months of therapy. In McSweeney’s (17) study, there was no significant change in the mouth opening rate during the first 1-9 months after radiation treatment.

Ozdere et al. (18) showed that trismus is a commonly observed sequela in patients who have undergone radiation therapy to treat malignancies of the head and neck.

According to the present findings, the adverse effects of radiotherapy were a pain in the ear and jaw region and exhibited a statistically significant association with the radiation dosage one month after treatment, and discomfort in the mouth region increased with age and gender.

Patients who undergo RT for HNC can develop hearing especially when receiving 60 Gy. Complaints include ear heaviness, earache, decreased hearing, tinnitus, and dizziness (19).

Epstein et al. (12) showed that as radiation exposure rose, somatic nerve injury increased, followed by pain in the regions exposed to radiation. In the research by Rabiei et al. (8), increasing the dosage was associated with ear and tooth discomfort.

Around 1950, external beam radiotherapy was performed with a device that produced a voltage greater than 300 kvp. After that, with the development of cobalt devices in the 1950s and 1960s, kilovoltage devices were used less. It is worth mentioning that the gamma-ray therapy devices are divided into several categories based on energy and type of operation. Megavoltage therapy devices include accelerators and gamma-ray teletherapy devices such as cobalt (Co60). The Cobalt 60 is an old device and has its own disadvantages. It burns the skin in high doses because it does not protect the skin. Also, this device has penumbra due to not having a point source of radiation production. Besides, as a result of the interaction between gamma photons and the source itself, its casing, and collimators of the device, low-energy, and scattered gamma-rays are produced, and for this reason, the uniformity of the beam is slightly reduced. Therefore, it seems that the side effects caused by radiotherapy can be minimized by using new devices (20,21).

Conclusion

Following one month of therapy, these adverse effects reach their maximum rate, and from then until the end of the third month after treatment, they continue to improve until they approach near to their pre-treatment levels.

Acknowledgments

The authors would like to express their gratitude to the Vice Deputy of Research at Kerman University of Medical Sciences for their financial support (Reg. No. 99000471).

Ethics

Ethics Committee Approval: This project was approved by the Ethical Committee of Kerman University of Medical Sciences of the university with the code IR.KMU.REC.1399.488 (date: 17.08.2023).

Informed Consent: Informed consent was obtained.

Peer-review: Externally and internally peer-reviewed.

Authorship Contributions

Concept: M.A.H., Design: M.A.H., Data Collection or Processing: A.E., A.R.G.N., Analysis or Interpretation: A.R., Literature Search: A.R., Writing: A.R.G.N.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: This work was supported by Kerman University of Medical Sciences (reg. no: 99000471).