| Objective To evaluate the value of 3D-printed handheld rod (3DP-HR) and surface-guided radiotherapy (SGRT) in reducing setup errors of nasopharyngeal carcinoma patients, especially in improving positional reproducibility in the lower neck, thoracic vertebrae, and clavicle. Methods A retrospective analysis was conducted for 60 nasopharyngeal carcinoma patients treated in Beijing Cancer Hospital. These patients were equally divided into three groups, namely the conventional, 3DP-HR-improved, and 3DP-HR+SGRT-improved groups, where patients were treated with conventional setup, improved setup using 3DP-HRs, and improved setup using 3DP-HRs combined with SGRT, respectively. The study compared the setup errors in the planning target volume (PTV) and multiple regions of interest (ROIs) (including seven cervical vertebrae (C1-C7), the first thoracic vertebra (T1), the occipital bone, the oral cavity, and bilateral clavicles) among the three groups. Results Regarding the PTV, the 3DP-HR-improved group exhibited setup errors of (-0.02 ± 0.05), (0 ± 0.05), and (0 ± 0.04) cm in three linear directions, i.e., vertical, longitudinal, and lateral, respectively, and (0.10 ± 0.85)°, (-0.07 ± 1.04)°, and (-0.03 ± 0.78)° in three rotational directions, i.e., pitch, roll, and rotation, respectively. In contrast, the 3DP-HR+SGRT-improved group demonstrated setup errors of (-0.01 ± 0.05), (-0.01 ± 0.05), and (-0.01 ± 0.05) cm in the vertical, longitudinal, and lateral directions, respectively, and (0.02 ± 0.77)°, (-0.12 ± 0.77)°, and (0.04 ± 0.49)° in the pitch, roll, and rotation directions, respectively. Compared to the conventional group, the two improved groups presented significantly enhanced linear setup accuracy (F = 9.32, 19.66, 18.48, P< 0.05), with statistical significance identified in roll and rotation angles (F = 9.52, 6.88, P < 0.05). In terms of ROIs, both the improved groups outperformed the conventional group in linear setup errors in the T1, oral cavity, and bilateral clavicles, with statistically significant intergroup differences (F = 58.16, 11.13, 57.08, 35.92, P < 0.05). The 3DP-HR+SGRT-improved group outperformed the other two groups in the rotational setup errors in C3, C4, C7, and bilateral clavicles, with statistically significant inter-group differences (F = 11.13, 13.49, 6.58, 5.47, 27.14, P < 0.05). Furthermore, the 3DP-HR-improved group exhibited significantly lower setup errors than the other two groups in the setup errors in the T1, with statistically significant inter-group differences (F = 9.03, P< 0.05). Conclusions The 3DP-HR-improved and 3DP-HR+SGRT-improved groups can significantly reduce the setup errors for nasopharyngeal carcinoma patients during radiotherapy, providing reliable clinical support. |
