The control group received the department’s current routine nursing care and standard health education. Education was typically delivered in the ward by the responsible nurse after iodine-125 seed implantation, primarily in the form of brief verbal explanations, without unified courseware, a fixed duration, or standardized operating procedures. The core content focused on the three fundamental principles of radiation protection—“time, distance, and shielding”—while advising patients to minimize close contact with sensitive populations, such as infants, young children, and pregnant women, after discharge and to reasonably limit the duration of close contact. General emergency management reminders were also provided for unexpected situations, such as suspected seed dislodgement. Regarding the use of radiation protection equipment, such as protective clothing, healthcare professionals usually offered recommendations or reminders during education; however, they did not provide continuous supervision, feedback, or reinforcement regarding whether patients actually wore such equipment. After discharge, no structured, periodic, proactive follow-up intervention was conducted, and follow-up was performed only according to the routine outpatient review process. To clarify the differences between the control and intervention groups, the intervention components and contact frequency in the two groups are compared in Table 1.

3.2.1. Establishment of the Intervention Team

A family-participatory radiation protection training intervention team was established and coordinated by the project leader. The team comprised physicians specializing in oncology, interventional medicine, radiotherapy, and nuclear medicine, oncology specialist nurses, nursing managers, and research nurses. Responsibilities were assigned by role: physicians were responsible for reviewing treatment-related risk points and key aspects of radiation safety; specialist nurses delivered the core protection content, provided skills demonstrations, and conducted scenario-based simulations; research nurses were responsible for enrollment communication, organization and implementation of training, follow-up contact, and process documentation; and nursing managers oversaw intervention quality control and consistency supervision.

3.2.2. Development of the Intervention Protocol and Pilot Testing

1) Development of the initial draft: Evidence related to home radiation protection and health education after iodine-125 seed implantation was systematically retrieved. In conjunction with common clinical cognitive biases and difficulties in home implementation, an initial draft of the intervention program was developed, accompanied by standardized training slides, key-action cards, key points for misconception clarification, scenario simulation scripts, follow-up scripts, and a Home Protection Action Plan.

2) Expert consultation: Experts in relevant fields were invited to review and revise the program in terms of content coverage, operability, cultural adaptability, and training duration and procedures, resulting in a revised draft.

3) Pilot testing: Before the formal study, a small-sample pilot test was conducted following the “enrollment-training-follow-up” process to evaluate feasibility and acceptability. Based on feedback, minor adjustments were made to the course pace, proportion of practice exercises, wording of materials, and timing of follow-up reminders, after which the final intervention protocol and key quality control points will be finalized.

3.2.3. Implementation Process

On the basis of routine care, the intervention group received family-participatory training, in which each patient was required to designate one family caregiver to participate jointly in the training and practice sessions. The caregiver was positioned as a collaborative learner and behavioral supporter; the outcome measures in this study were assessed in patients. During hospitalization, a two-stage structured training program was completed using a closed-loop approach of “instruction-demonstration-practice-return demonstration-planning”. The teach-back method was used to verify patients’ understanding of key protective points and their ability to perform the required procedures; those who had not mastered them received immediate correction and reinforcement [7].

1) Stage 1: Contextualized inpatient education (30 - 40 min): Focusing on particle characteristics, radiation attenuation, and safety boundaries, executable actions based on the principles of “time-distance-shielding” were specified for the home setting, including management of contact with sensitive groups such as infants, young children, and pregnant women; control of close-contact duration; household zoning; and cleaning management of personal items. On-site visualization exercises were conducted using measuring tapes and adhesive markers, such as marking safe distances of 1.0 m and 1.5 m, to guide patients in translating abstract principles into a practicable behavioral checklist for home implementation.

2) Stage 2: Belief reinforcement and personalized action planning (30 - 40 min): Case discussion and misconception clarification were used to conduct risk communication targeting two types of bias—“excessive fear leading to avoidance and isolation” and “underestimation of risk leading to nonadherence or perfunctory adherence”—thereby strengthening perceptions of the necessity and controllability of protective behaviors. Scenario-based simulation training was also organized (e.g., suspected seed dislodgement, body fluid contamination, and communication during security screening when going out). The design and implementation of the simulations followed best-practice standards for healthcare simulation, including prebriefing, enactment, and debriefing/reflection, to improve training consistency and evaluability [8]. An individualized Home Radiation Protection Action Plan was developed based on each patient’s home living conditions, specifying key goals, implementation frequency, barrier-management strategies, and forms of support from family members. Before discharge, key points were reconfirmed and supplementary training was provided using the teach-back method and a checklist of critical actions.

3.2.4. Post-Discharge Follow-Up and Consolidation

Structured follow-up was implemented after discharge: once weekly within the first month after discharge, and once each at 3 and 6 months after discharge. Follow-up was conducted using a standardized script via telephone or WeChat to check the implementation of the action plan, identify problems, provide targeted feedback, and offer necessary emotional support and referral guidance. In addition, protective measures and answers to frequently asked questions were regularly disseminated through WeChat groups, forming a closed-loop support process of “reminder-checking-feedback-reinforcement”. Previous systematic reviews have shown that transitional care delivered via mobile platforms such as WeChat can significantly improve psychological outcomes, including anxiety, in patients with cancer and promote the maintenance and implementation of post-discharge health management behaviors [9].

3.2.5. Quality Control

To ensure intervention homogeneity and the reliability of the study findings, patient education and follow-up in both groups were delivered by designated research nurses, who received standardized training and passed competency assessments before implementation, and all procedures were conducted according to standard protocols. Outcome assessments were conducted by two trained nurses who were not involved in intervention implementation. However, because of the behavioral nature of the intervention, complete blinding of outcome assessors could not be guaranteed. Therefore, outcome assessment was considered unblinded, and potential measurement bias was acknowledged as a limitation of this study. Given the marked differences in the content and format of the interventions, blinding was not implemented for participants or intervention providers in this study. After enrollment, patient information files were established, including demographic and clinical characteristics, contact information, intervention implementation records (stage, duration, completion of practice sessions, and pre-discharge checklist results), follow-up completion status, and feedback, for process tracking and quality audits. Quality control personnel regularly reviewed the completeness of records and the implementation of key procedures, and any deviations identified were promptly corrected. To minimize contamination between groups, intervention materials and online push notifications for the intervention group were made available only to that group. In summary, the experimental and control groups differed in intervention recipients, degree of content structuring, mode of delivery, and post-discharge follow-up/online support; the specific comparison is shown in Table 1.

1) General characteristics

The questionnaire was developed by the researchers. The patient-related section mainly included age, sex, educational level, place of residence, and per capita monthly household income. Disease- and treatment-related characteristics included the site of the current iodine-125 seed implantation (target area), tumor stage, pathological nature of the tumor treated in the current implantation, comorbid chronic diseases, and dosimetric parameters (prescription dose). Family/caregiver characteristics included the relationship between the primary caregiver and

Table 1. Comparison of interventions and contact frequency between the two groups.

the patient, family structure, and whether the patient lived with children or pregnant women. Patients in both groups completed the questionnaire at enrollment under standardized guidance from a research nurse. Information on implantation site, tumor stage, and dosimetric parameters was verified and supplemented by the research nurse using medical records and treatment planning system records to ensure the authenticity and consistency of the data.

2) Patient compliance with radiation protection

Patients’ implementation of home-based radiation protection behaviors was assessed using the Questionnaire on the Implementation Status of Radiation Protection Standards in Patients after ¹²⁵I Seed Implantation, developed by Zhou based on the Requirements for Radiation Protection in Permanent Implantation Therapy with Seed Sources (GBZ 178-2017) [10]. The questionnaire was developed through a literature review, group discussion, two rounds of expert consultation, and a pilot survey. The expert authority coefficient was 0.89, and the Kendall coordination coefficient was 0.795 (P < 0.001), indicating good content validity and expert agreement. The questionnaire comprises 18 items across three dimensions: time protection (6 items), distance protection (7 items), and shielding protection (5 items), with response options of “yes”, “no”, and “unclear”. Total and dimensional scores were calculated according to the questionnaire scoring rules. Patients who implemented ≥12 applicable items (implementation rate ≥ 66.7%) were classified as having “good standard implementation”, which was used to compare changes in radiation protection compliance between the two groups before and after the intervention. For each participant, applicable items were determined according to individual household exposure conditions. For example, items related to contact with pregnant women or children were excluded from the denominator when these individuals were not present in the patient’s household. Therefore, the number of applicable items and the maximum possible score could vary according to individual living circumstances. Each implemented protective behavior was assigned 1 point, whereas non-compliant or unclear behaviors were assigned 0 points. The total compliance score was calculated as the sum of completed protective behaviors. The implementation rate was calculated as the number of compliant items divided by the number of applicable items. Patients achieving an implementation rate ≥ 66.7% were classified as having good radiation protection adherence.

3) Patient anxiety level

Patient anxiety was assessed using the Generalized Anxiety Disorder-7 (GAD-7) scale [11]. This self-report scale comprises seven items and assesses the frequency of anxiety-related symptoms over the preceding 2 weeks. It uses a 4-point Likert scoring system (0 = “not at all”, 1 = “several days”, 2 = “more than half the days”, and 3 = “nearly every day”), with a total score ranging from 0 to 21; higher scores indicate greater anxiety severity. Scores of 5, 10, and 15 are used as the cutoffs for mild, moderate, and severe anxiety, respectively. The Chinese version of the GAD-7 has demonstrated good psychometric properties in studies of patients with cancer, with an internal consistency Cronbach’s α of approximately 0.91, and can be used for anxiety screening and severity assessment [12]. The scale was completed independently by patients, while research nurses provided standardized instructions and checked for missing responses on site to ensure data completeness.

4) Assessment of quality of life in patients with malignant tumors

Assessment was conducted using the Chinese version of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30, version 3. This Chinese version was translated and culturally adapted by Wan et al., and has demonstrated good reliability, validity, and responsiveness among Chinese patients with cancer [13]. The QLQ-C30 comprises 30 items covering five functional domains (physical, role, cognitive, emotional, and social functioning), three symptom domains (fatigue, pain, and nausea/vomiting), and one global health status domain. Items are scored using 4-point and 7-point Likert scales, and all domain scores are standardized to a 0 - 100 scale; higher functional and health status scores indicate better functioning and health, whereas higher symptom scores indicate greater symptom burden. The primary quality-of-life outcome was the global health status/QoL score of the EORTC QLQ-C30. The score was calculated according to the EORTC scoring manual using items 29 and 30 and transformed into a 0 - 100 scale. Higher scores indicated better overall health status and quality of life.

Data were collected from both groups at five time points. At T0, on the day of admission after informed consent was obtained, the general information questionnaire was administered, and baseline assessments were completed using the Radiation Protection Standards Implementation Questionnaire, the GAD-7, and the QLQ-C30. At T1, within 24 h before discharge after the intervention, the Radiation Protection Standards Implementation Questionnaire, GAD-7, and QLQ-C30 were administered again. T2, T3, and T4 corresponded to 1 month (±7 d), 3 months (±7 d), and 6 months (±7 d) after discharge, respectively, when the same scales were completed through outpatient follow-up visits, WeChat, or telephone follow-up. Questionnaires were distributed and collected by uniformly trained researchers. Standardized informed explanations and instructions were provided before completion to ensure neutrality of responses; for participants with reading or writing difficulties, researchers provided assistance. Immediately after collection, the questionnaires were checked on site for completeness and logical consistency to ensure data validity.

Statistical analyses were performed using SPSS version 26.0. Measurement data were assessed for normality and homogeneity of variance. Normally distributed data are expressed as mean ± standard deviation ( x ¯ ± s ); between-group comparisons were performed using the independent-samples t test, and Welch’s t test was used when variances were unequal. Non-normally distributed data are expressed as median (interquartile range), and between-group comparisons were performed using the Mann-Whitney U test. Categorical data are expressed as frequencies (n) and percentages (%), and between-group comparisons were performed using Pearson’s χ² test, with continuity correction applied when necessary. Repeated-measures analysis of variance was used to analyze GAD-7 and EORTC QLQ-C30 scores measured at multiple time points from T0 to T4; sphericity was assessed using Mauchly’s test, and Greenhouse-Geisser-corrected results were reported. Repeated-measures analysis of variance was used to analyze changes in radiation protection compliance scores across different time points, with group as the between-subject factor and time as the within-subject factor. The main effects of group, time, and group × time interaction were evaluated. When the assumption of sphericity was violated, Greenhouse-Geisser correction was applied. Simple effects analyses were subsequently performed to compare between-group differences at each time point. The proportion of patients achieving good radiation protection adherence was compared between the two groups at each time point using Pearson’s χ² test or Fisher’s exact test when appropriate. The significance level was set at α = 0.05 (two-sided).

A total of 90 patients were randomized into the intervention group (n = 45) and control group (n = 45). All randomized participants completed the 6-month follow-up, with no withdrawals, losses to follow-up, or missing repeated-measures data. Therefore, all participants were included in the final analysis. The mean age was 64.69 ± 10.15 years in the intervention group and 62.71 ± 9.80 years in the control group, with no significant difference between groups (P > 0.05). No significant differences were observed between the two groups in sex, educational level, place of residence, monthly household income per capita, implantation site, tumor stage, tumor characteristics, comorbid chronic diseases, prescription dose, caregiver relationship, family structure, or cohabitation with children or pregnant women (all P > 0.05), indicating that the two groups were comparable at baseline (Table 2).

Table 2. Comparison of baseline characteristics between the two groups of patients.

Note: Continuous variables are presented as mean ± standard deviation and compared using independent-samples t tests or Welch’s t tests when appropriate. Categorical variables are presented as n (%) and compared using Pearson’s χ² test. *The primary caregiver refers to the family member who provided the main daily care and support for the patient.

Radiation protection compliance scores were compared between the two groups at different time points. Repeated-measures analysis of variance was performed, with group (intervention/control) as the between-subjects factor and time (T0 - T4) as the within-subjects factor. Mauchly’s test was used to assess the assumption of sphericity, and Greenhouse-Geisser correction was applied when necessary.

The repeated-measures ANOVA demonstrated significant main effects of group (F = 18.624, P < 0.001), time (F = 286.517, P < 0.001), and group × time interaction (F = 15.836, P < 0.001), indicating that radiation protection compliance changed significantly over time and that the trajectories differed between the intervention and control groups (Table 3).

Table 3. Overall repeated-measures ANOVA results for radiation protection compliance scores.

Simple effects analysis showed that there was no statistically significant difference in compliance scores between the two groups at baseline (T0) (P = 0.396). Compared with the control group, the intervention group showed significantly higher compliance scores at T1, T2, and T3 (all P < 0.05). However, no statistically significant difference was observed between the two groups at T4 (P = 0.896). Compliance scores decreased gradually in both groups at T3 and T4, which may be associated with progressive radioactive decay of iodine-125 seeds and reduced need for intensive radiation protection behaviors during long-term follow-up (Table 4).

Table 4. Simple effects analysis of radiation protection compliance scores between the intervention and control groups at different time points.

The proportions of patients achieving good radiation protection adherence were compared between the two groups at each follow-up time point using Pearson’s χ² test. At baseline (T0), no significant difference was observed between the two groups, indicating comparability. From T1 to T3, the intervention group showed significantly higher rates of good adherence than the control group (all P < 0.05). At T4, no significant difference was observed between the two groups (Table 5).

Table 5. Comparison of good radiation protection adherence rates between the intervention and control groups at different follow-up time points.

The repeated-measures ANOVA demonstrated significant main effects of time (F = 268.421, P < 0.001) and group (F = 18.632, P < 0.001), as well as a significant group × time interaction (F = 6.917, P < 0.001), indicating that anxiety levels changed differently over time between the intervention and control groups. Simple effects analysis showed that there was no statistically significant difference in anxiety scores between the two groups at baseline (T0) (P = 0.402). Compared with the control group, the intervention group showed significantly lower anxiety scores at T1 (P = 0.007), T2 (P < 0.001), and T3 (P = 0.001). However, no statistically significant difference was observed between the two groups at T4 (P = 0.197) (Table 6 and Table 7).

Table 6. Comparison of anxiety scores between the two groups of patients.

Table 7. Simple effects tests at different time points.

Repeated-measures analysis of variance (ANOVA) was used to compare quality-of-life scores between the two groups at different time points, with group (intervention/control) as the between-subjects factor and time (T0 - T4) as the within-subjects factor. The analyzed outcome was the global health status/QoL score of the EORTC QLQ-C30. Mauchly’s test indicated that the assumption of sphericity was violated (P < 0.05); therefore, the Greenhouse-Geisser correction was applied.

The repeated-measures ANOVA demonstrated significant main effects of group (F = 22.514, P < 0.001), time (F = 31.872, P < 0.001), and group × time interaction (F = 8.426, P < 0.001), indicating that quality-of-life trajectories differed significantly between the intervention and control groups over time. Simple effects analysis showed that there was no statistically significant difference in quality-of-life scores between the two groups at baseline (T0) (P = 0.698). Compared with the control group, the intervention group showed significantly higher quality-of-life scores at T1 (P = 0.028), T2 (P < 0.001), T3 (P = 0.020), and T4 (P < 0.001) (Table 8 and Table 9).

Table 8. Comparison of EORTC QLQ-C30 global health status/QoL scores between the two groups.

Table 9. Simple effects analysis of between-group differences in EORTC QLQ-C30 global health status/QoL scores at different time points.

This study demonstrated that family-participatory radiation protection transitional care significantly improved radiation protection adherence during hospitalization and the early post-discharge period (T1 - T3), but the between-group difference was no longer significant at 6 months (T4). At follow-up to T4, the between-group difference was no longer significant, and adherence indicators declined in both groups, suggesting that the intervention effect may diminish over time and may also be related to reduced protection needs after radiation attenuation. These findings are consistent with previous studies on empowerment management and related approaches [6], indicating that intervention strategies centered on capacity building, enhancement of self-efficacy, and continuous support may help improve the implementation of protective behaviors. In this study, caregivers jointly participated in training and scenario-based practice, teach-back verification, and action plan development, enabling families to assume reminder and support roles after discharge and thereby enhancing the operability and stability of protective behaviors. From mechanistic and evidence-based perspectives, iodine-125 seed implantation is a form of low-dose-rate brachytherapy, and the overall radiation risk is controllable; however, safety depends on patients’ sustained implementation of key measures such as time, distance, and shielding in real-life contexts [1]. Relevant dosimetric studies also support that, provided protective strategies are implemented according to standards, external exposure can be controlled within an acceptable range [14]. Therefore, this study provides evidence for optimizing routine verbal instruction into a continuity-of-care pathway characterized by family participation, scenario-based training, and follow-up reinforcement. From the perspective of the Knowledge-Attitude-Practice (KAP) theory, family-participatory training can strengthen protection-related knowledge and risk awareness, enhance perceived controllability, and, with caregivers’ reminders and assistance, promote the sustained implementation of protective behaviors, thereby reducing concerns and alleviating anxiety. This study only evaluated the intervention effect and did not directly measure knowledge, attitudes, or mechanistic pathways.

The results of this study showed no statistically significant difference in baseline (T0) anxiety scores between the two groups. After the intervention, the anxiety score in the intervention group at T1 (24 h before discharge) was significantly lower than that in the control group, and this difference persisted at T2 (1 month after discharge) and T3 (3 months after discharge), suggesting that family-participatory continuing care for radiation protection exerted an immediate to short- and medium-term anxiolytic effect. By T4 (6 months after discharge), the between-group difference was no longer significant, indicating an attenuation of the long-term effect. The underlying mechanisms may be as follows: during the transition to home care while carrying the radioactive source, patients are prone to anxiety due to uncertainty about risks. Through scenario-based education, rehearsal of key procedures, and teach-back verification, the training translated the principles of “time-distance-shielding” into actionable strategies, while caregivers provided reminders and support, thereby enhancing patients’ perceived risk controllability and self-efficacy and reducing anxiety. After patients entered the long-term home-care stage, they gradually adapted, became more proficient in protective measures, and obtained more follow-up examinations and information; together with radiation decay, these factors reduced the perceived threat, leading to decreased anxiety in the control group as well and a narrowing of the between-group difference. Previous studies have also suggested that the effects of education and communication interventions on anxiety are generally more pronounced in the early stage and tend to converge later: Liu et al. reported mid-term improvement, whereas the difference weakened at the end of follow-up [15]. Atwood et al. also confirmed that the benefits of counseling were more prominent in the early stage [16]; Lim et al. observed an immediate reduction in anxiety after brachytherapy, but the follow-up effect diminished [17]. Accordingly, intensified follow-up or supplementary training (e.g., digital reminders and refresher training in risk communication) is recommended at 3 - 6 months after discharge to consolidate long-term emotional benefits.

The results of this study showed no statistically significant difference in quality-of-life scores between the two groups at baseline (T0), indicating comparability. After the intervention, quality-of-life scores in the intervention group were significantly higher than those in the control group at T1 - T4, suggesting that family-participatory radiation protection-based transitional care confers sustained benefits for health-related quality of life in patients undergoing iodine-125 seed implantation. Notably, scores in both groups peaked at T2 and then declined at T3 and T4, with a gradual narrowing of between-group differences, indicating that quality of life is influenced by multiple factors, including disease progression, treatment burden, and adaptation over time, and that the long-term intervention effect may be partially attenuated. This finding is consistent with previous evidence that structured nursing interventions improve quality of life: a randomized controlled study by Choi et al. showed that nurse-led supportive care improved functional domains related to the EORTC QLQ-C30 and yielded quality-of-life benefits [18]; Liu et al. also reported that individualized nursing, through symptom assessment, psychological support, and lifestyle guidance, significantly improved overall QLQ-C30 quality of life in patients with lung cancer and alleviated fatigue, pain, and emotional functioning [19]; and a telenursing educational intervention by Muñoz-Villaverde et al. similarly demonstrated improvements in quality of life, suggesting that “continuous education plus follow-up support” is an important pathway [20]. Considering the characteristics of the intervention in this study, family-participatory radiation protection-based transitional care contextualizes and operationalizes key principles such as “time, distance, and shielding”, while strengthening daily implementation through caregiver support. This approach may help reduce uncertainty and avoidance behaviors associated with living at home with radioactive sources, and may promote self-management and recovery of social functioning. In addition, improved adherence and reduced anxiety may jointly enhance QLQ-C30 dimensions such as emotional and role functioning, thereby increasing overall quality of life. These findings suggest that family co-participation, contextualized rehearsal, and continuous post-discharge support should be incorporated into continuity-of-care pathways, and that future studies should further evaluate their long-term effects and associated influencing factors.