ABSTRACT
Objective:To explore the clinical application value of Bodyfix fixation device in stereotactic body radiotherapy (SBRT) for elderly patients with lung cancer.Methods:The clinical data of 63 elderly patients with lung cancer who received SBRT in Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from January to October 2021 were retrospectively analyzed. According to different fixation methods, the patients were divided into Bodyfix combined with vacuum bag fixation device group (Bodyfix group, 20 cases) and 4D respiratory gating technology combined with vacuum bag fixation device group (vacuum bag group, 43 cases). Cone beam CT (CBCT) was used for position verification before each treatment, linear and rotational errors in the horizontal (X), head-to-foot (Y), front-to-back (Z) directions were recorded.Results:The linear errors of Bodyfix group in the X, Y and Z directions were 1.7 mm (1.3 mm, 3.0 mm), 4.6 mm (4.3 mm, 5.3 mm) and 1.3 mm (0.8 mm, 2.8 mm), and the rotational errors were (0.46±0.04)°, (-0.48±0.05)° and 0.64°(0.38°, 1.07°); the linear errors of vacuum bag group in the X, Y and Z directions were 2.1 mm (1.6 mm, 3.3 mm), 2.8 mm (1.8 mm, 3.7 mm) and 3.0 mm (2.3 mm, 3.8 mm), and the rotational errors were (0.69±0.04)°, (-0.70±0.04)° and 0.64° (0.42°, 0.86°). The differences in linear errors in the Y and Z directions and rotational errors in the X and Y directions between the two groups were statistically significant ( P values were <0.001, <0.001, 0.003 and 0.007). Conclusions:Compared with the 4D respiratory gating technology, the Bodyfix fixation device has smaller rotational errors in the X and Y directions and linear errors in the Z direction. It can be used as an effective method of postural fixation for SBRT in elderly patients with lung cancer.
ABSTRACT
Objective:To compare the difference between active breathing coordinator (ABC) technique and free breathing (FB) mode combined with bodyfix stereotactic radiotherapy (SBRT) for chest tumors.Methods:40 thoracic tumor patients receiving SBRT were randomly selected and divided into the ABC technique group and FB model group. After fixation with bodyfix fixing devices in two groups, cone-beam CT (CBCT) scan images before each SBRT were matched with the plan reference images. The setup errors in the left-right (LR), superior-inferior (SI) and anterior-post (AP) directions were obtained. Then, the setup errors were corrected. SBRT was performed and split intra-fraction CBCT was conducted simultaneously, which was repeated until the end of treatment.Results:In the ABC technique group, the setup errors in the LR, SI and AP directions were (0.25±0.21) cm, (0.28±0.21) cm, and (0.21±0.24) cm, significantly less compared with (0.31±0.22) cm, (0.32±0.21) cm and (0.37±0.23) cm in the FB model group (all P<0.05). The V 30Gy of the heart, the V 20Gy and V 30Gy of the lung in the ABC technique group were significantly less than those in the FB model group (0.31%∶7.35%; 24.5%∶32.9%; 19.5%∶25.8%, all P<0.05). Conclusions:ABC technique combined with bodyfix fixation device may be superior to FB mode in SBRT for chest tumors, which remains to be validated by subsequent studies with large samples.