Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Department of Oncology, Chengdu First People's Hospital, Chengdu, Sichuan, China.
Clin Oncol (R Coll Radiol). 2023 Dec;35(12):e657-e665. doi: 10.1016/j.clon.2023.09.007. Epub 2023 Sep 22.
To conduct a direct comparison regarding the non-coplanar positioning accuracy between the optical surface imaging system Catalyst HD and non-coplanar cone-beam computed tomography (NC-CBCT) in intracranial single-isocentre non-coplanar stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HSRT).
Twenty patients with between one and five brain metastases who underwent single-isocentre non-coplanar volumetric modulated arc therapy (NC-VMAT) SRS or HSRT were enrolled in this study. For each non-zero couch angle, both Catalyst HD and NC-CBCT were used for set-up verification prior to beam delivery. The set-up error reported by Catalyst HD was compared with the set-up error derived from NC-CBCT, which was defined as the gold standard. Additionally, the dose delivery accuracy of each non-coplanar field after using Catalyst HD and NC-CBCT for set-up correction was measured with SRS MapCHECK.
The median set-up error differences (absolute values) between the two positioning methods were 0.30 mm, 0.40 mm, 0.50 mm, 0.15°, 0.10° and 0.10° in the vertical, longitudinal, lateral, yaw, pitch and roll directions, respectively. The largest absolute set-up error differences regarding translation and rotation were 1.5 mm and 1.1°, which occurred in the longitudinal and yaw directions, respectively. Only 35.71% of the pairs of measurements were within the tolerance of 0.5 mm and 0.5° simultaneously. In addition, the non-coplanar field with NC-CBCT correction yielded a higher gamma passing rate than that with Catalyst HD correction (P < 0.05), especially for evaluation criteria of 1%/1 mm with a median increase of 12.8%.
Catalyst HD may not replace NC-CBCT for non-coplanar set-up corrections in single-isocentre NC-VMAT SRS and HSRT for single and multiple brain metastases. The potential role of Catalyst HD in intracranial SRS/HSRT needs to be further studied in the future.
比较光学表面成像系统 Catalyst HD 与非共面锥形束 CT（NC-CBCT）在颅内单等中心非共面立体定向放射外科（SRS）和分次立体定向放射治疗（HSRT）中的非共面定位精度。
本研究纳入了 20 例接受单等中心非共面容积调制弧形治疗（NC-VMAT）SRS 或 HSRT 的脑转移瘤患者。对于每个非零治疗床角度，在进行射束治疗之前，均使用 Catalyst HD 和 NC-CBCT 进行摆位验证。将 Catalyst HD 报告的摆位误差与 NC-CBCT 得出的摆位误差进行比较，后者被定义为金标准。此外，使用 Catalyst HD 和 NC-CBCT 进行摆位校正后，使用 SRS MapCHECK 测量每个非共面射野的剂量传递精度。
两种定位方法的中位摆位误差差值（绝对值）分别为 0.30mm、0.40mm、0.50mm、0.15°、0.10°和 0.10°，分别在垂直、纵向、横向、偏航、俯仰和滚转方向上。在纵向和偏航方向上，平移和旋转的最大绝对摆位误差差值分别为 1.5mm 和 1.1°。只有 35.71%的测量值对同时在 0.5mm 和 0.5°的容差范围内。此外，经 NC-CBCT 校正的非共面射野的伽马通过率高于经 Catalyst HD 校正的射野（P＜0.05），特别是对于 1%/1mm 的评估标准，中位提高了 12.8%。
在单等中心 NC-VMAT SRS 和 HSRT 治疗单发和多发脑转移瘤中，Catalyst HD 可能无法替代 NC-CBCT 进行非共面摆位校正。未来需要进一步研究 Catalyst HD 在颅内 SRS/HSRT 中的潜在作用。
