This study is a cross-sectional one and the participants were selected at the Thyroid Cancer Center Outpatient Clinic of Oncology, Head and Neck Surgery Department at the Hasan Sadikin General Hospital, Faculty of Medicine, Padjadjaran University, Bandung, West Java, Indonesia, from 2021 to 2022. Included subjects who had previously been diagnosed with thyroid cancer before the age of 18-year-old. A follow-up of less than 5 years, a diagnosis made after the age of eighteen, or a PTC diagnosis as a second malignant neoplasm (SMN) are all exclusion factors.

At the outpatient clinic, everyone was required to independently fill out the written questionnaires. Medical records were used to gather data on the demographics as well as clinical characteristics (such as diagnostic cancer stage, type of pathology, and type of therapy received) of each subject. The Helsinki Declaration was followed in the conduct of this investigation, and it was approved by the Institutional Ethical Review Boards at Hasan Sadikin General Hospital. Each participant signed an informed consent in a written form before enrolling in this study.

The survey items were based on the original version of the ThyCA-QoL, which consists of 24 items of thyroid cancer-specific questionnaire developed based on the EORTC guidelines [8, 9]. First, it was translated from English to Indonesian by a qualified professional translator fluent in both languages. A group of specialists examined the translated questionnaire after which small adjustments were made to adapt and improve the translation. Afterward, the translated Indonesian questionnaire was translated back to English to verify the questionnaire’s original meaning, it was translated by a second certified professional translator. Finally, the Indonesian ThyCA-QoL questionnaire was evaluated on respondents.

The responder is then asked (verbally by the interviewer or via an open-ended question) to explain what they believed each questionnaire item and their related response signified. Using this method, the researcher may make sure that the translated items have the same meaning as the original items and that the translated questionnaire is clear. We used respondent-to-item ratios of 1:3 since the pediatric thyroid cancer patient population was quite small.

The questionnaire consists of seven multi-item scales namely neuromuscular, voice, concentration, sympathetic, throat and mouth, psychological and sensory problems, and six single items relating to problems with scars, feeling chilly, tingling at hands/feet, gained weight, headaches, and interest in sex. Additionally, the questionnaire has a deadline: each item has a week to be completed, except for sexuality, which was four weeks. The Likert scale, which ranges from 1 (not at all) to 4 (very much), was used to evaluate the intensity of the complaints. More complaints correspond to symptoms with higher scores.

The Indonesian version of the EORTC QLQ-C30 (version 3.0) questionnaire includes thirty items and measures five functional scales (physical, role, emotional, cognitive, and social functioning), global health status (GHS), financial difficulties, and eight symptom scales (fatigue, nausea, and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, diarrhea). The evaluation time frame is the previous week of the questionnaire reception. All items are scored on a Likert four-point response ranging from 1, “not at all” to 4, “very much”, except for the global health status scale including 2 items scored on a seven-point modified linear analog scale ranging from 1, “very poor” to 7, “excellent” [15]. The EORTC scoring manual procedure provides a score from 0 to 100 for each dimension.

The primary outcome of this study is a translated and validated Indonesian version of the thyroid cancer-specific quality of life (ThyCA-QoL) questionnaire. The secondary outcome is to obtain data on demographic and clinical characteristics and ThyCA-QoL questionnaire results of pediatric thyroid cancer patients at the Hasan Sadikin General Hospital from 2021 to 2022.

Included subjects who had previously been diagnosed with thyroid cancer before the age of 18-year-old who visited the outpatient clinic of the thyroid cancer center, Oncology, Head and Neck Surgery Department at the Hasan Sadikin General Hospital/Faculty of Medicine, Padjadjaran University, Bandung, West Java, Indonesia, from 2021 to 2022. Exclusion criteria include a follow-up < 5 years, diagnosis after the age of 18 years old, or having been diagnosed with PTC as a second malignant neoplasm (SMN).

Descriptive methods were used for the purpose of evaluating demographic and clinical data. The items in the questionnaire were each translated and evaluated for validity. The validity of the questionnaire was assessed between the EORTC QLQ-C30 and the Indonesian ThyCA-QoL questionnaire. Criterion validity was also assessed using a correlation matrix between Indonesian ThyCA-QoL scale summary scores and the QLQ-C30 scale scores. The correlation between the Indonesian ThyCA-QoL and the QLQ-C30 scores assessing the same HRQoL domain was expected to be greater or equal than 0.4, in absolute value. Conversely, the correlation between each ThyCA-QoL scale score and other scales of the QLQ-C30 assessing other HRQoL domains was expected to be lower than 0.4. By identifying the Cronbach coefficient, which gauges internal consistency, the reliability was evaluated.

This study received approval from Hasan Sadikin General Hospital’s Ethics Committee number 0516070802 on June 15th, 2022. Then, written informed consent forms (Supplementary file 1) were obtained from each patient. The 1964 Helsinki Declaration and any updates thereto, as well as any relevant ethical standards, were followed in all procedures conducted in research involving human participants. These practices also adhere to institutional, governmental, and/or ethical research committee rules.