| Luo Xuechen,Wang Chan,Li Xiang,et al.Suitable patient populations of optical surface imaging for setup error correction during breast cancer radiotherapy using DIBH[J].Chinese Journal of Radiological Medicine and Protection,2026,46(6):581-586 |
| Suitable patient populations of optical surface imaging for setup error correction during breast cancer radiotherapy using DIBH |
| Received:August 13, 2025 |
| DOI：10.3760/cma.j.cn112271-20250813-00296 |
| KeyWords:Breast cancer|Deep inspiration breath-hold|Radiotherapy|Setup error |
| FundProject: |
| Author Name | Affiliation | E-mail | | Luo Xuechen | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | Wang Chan | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | Li Xiang | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | Yu Jialei | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | An Zimeng | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | Li Gaofeng | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | | | Xu Yonggang | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | stone1977coco@163.com | | Zhong Qiuzi | Department of Radiation Oncology, Beijing Hospital, National Center for Gerontology, Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China | |
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| Abstract:: |
| Objective To determine suitable patient populations with left-sided breast cancer for the application of optical surface imaging (OSI) to setup error correction during radiotherapy using deep inspiration breath-hold (DIBH). Methods A retrospective study was conducted on 53 patients with left-sided breast cancer who received radiotherapy using DIBH after breast-conserving surgery at the Department of Radiation Oncology of Beijing Hospital from August 2023 to May 2025. Based on their body mass index (BMI) values, these patients, with a median age of 47 years, were divided into three groups: obese group (BMI ≥ 28 kg/m2, n = 15), overweight group (24 kg/m2 ≤ BMI ≤ 27.9 kg/m2, n = 18), and normal-weight group (18.5 kg/m2 ≤ BMI ≤ 23.9 kg/m2, n = 20). For each patient, setup errors measured using the cone-beam computed tomography (CBCT) and OSI systems were recorded, denoted as E1 and E2, respectively. These errors included translational errors in the left-right (x), superior-inferior (y), and anterior-posterior (z) directions and rotational errors around the x, y, and z axes (Rx, Ry, Rz). The E2 errors were not applied to actual error correction. The correlation between the E1 and E2 errors was analyzed, followed by the calculation of their differences (Er = E1-E2) in translational directions. Differences between E1 and Er errors in translational directions were then compared for each group. Subsequently, E1 and Er were separately substituted into the isocenters of the original plans, generating re-planned E1 and Er. Dosimetric differences of planning target volumes (PTVs) and key organs at risk (OARs) between re-planned E1 and Er were compared across the three groups. The evaluation parameters included the V100 % of PTVs, the V5 Gy and V20 Gy of the left lung, the mean dose (Dmean) to the heart, and the Dmean and maximum dose (Dmax) to the left anterior descending (LAD) artery. Finally, using a margin formula, the PTV margins were calculated based on E1 and Er errors, denoted as MPTV1 and MPTVr, respectively. Results A total of 284 datasets of setup errors measured using CBCT and OSI each were collected. The correlations between E1 and E2 errors reveal that the obese group exhibited low correlations in the y, Rx, Ry, and Rz directions (r = 0.46, 0.47, 0.48, 0.41, P < 0.05), while other groups exhibited moderate correlations in other directions (r = 0.52-0.78, P < 0.05). The comparison between E1 and Er errors indicated that the overweight group showed statistically significant differences in the y direction ［(0.15 ±4.39)mm vs. (1.28 ±3.19) mm, t = -2.00, P < 0.05］; the normal-weight group exhibited statistically significant differences in both the x direction ［(-1.04 ±2.38)mm vs. (-0.14 ±2.03) mm, t = -3.34, P< 0.05］ and the y direction ［(-1.68 ±4.28) mm vs. (-0.03 ±2.89) mm, t = -2.68, P< 0.05), while minimal statistically significant differences were observed in other directions (P > 0.05). Dosimetric comparison between re-planned E1 and Er indicated that the overweight group displayed significant differences in both Dmean ［(13.36 ±4.77)Gy vs. (10.9 ±3.83) Gy］ and Dmax ［(33.15±1.43)Gy vs. (29.10±7.53) Gy］ to the LAD artery (t = 3.23, 2.48, P < 0.05). The normal-weight group showed statistically significant differences in both Dmean ［(12.58 ±5.06)Gy vs. (9.88 ±3.78) Gy］ and Dmax ［(34.56 ±8.65)Gy vs. (28.86 ±7.52) Gy］ to the LAD artery (t = 2.89, 2.30, P < 0.05), while no statistically significant differences were observed in other dosimetric parameters (P > 0.05). Additiontionally, the calculated MPTV1 and MPTVr in x, y, and z directions of the obsess group were 5.88, 9.45, 6.37 mm and 5.12, 8.92, 6.01 mm, respectively. While those of the overweight group were 5.23, 6.95, 5.73 mm and 4.57, 5.26, 5.35 mm, respectively, and those of the normal-weight group were 5.18, 6.68, 5.75 mm and 4.07, 5.02, 5.41 mm, respectively. Conclusions Among the left-sided breast cancer patients treated with radiotherapy using DIBH, those with normal weight or overweight (18.5 kg/m2 ≤ BMI ≤ 27.9 kg/m2) are suitable populations for OSI. For these patients, OSI can reduce their setup errors, effectively protect their OARs, and reduce PTV margins to approximately 5 mm. In contrast, for obese patients (BMI ≥ 28 kg/m2), OSI exhibits a diminished capacity for setup error correction, necessitating an increased frequency of CBCT scans. |
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