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Objective:To explore the application value of optical surface monitoring system (OSMS) volume rendering technique (VRT) body surface imaging in intensity-modulated radiotherapy for thoracic tumors.Methods:A retrospective case series study was performed. The clinical data of 65 patients with thoracic tumors treated with intensity-modulated radiotherapy at Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from September 2021 to October 2022 were retrospectively analyzed. In the first treatment,after cone-beam computed tomography (CBCT) scan and correction, VRT body surface images were obtained by using OSMS. In subsequent treatment, the VRT image was used as the benchmark and the 6-dimensional bed was automatically positioned to record the 6-dimensional bed positioning value. The CBCT scan was performed to record the translation and rotation errors of left-right direction (X-axis), head-foot direction (Y-axis) and front-rear direction (Z-axis). After the calibration of the 6-dimensional automatic bed shifting, the new real-time deltas (RTD) value of digital imaging and communications in medicine (DICOM) body surface image was recorded, and the new VRT image was obtained. CBCT registration error value was defined as VRT image-guided setup error. The sum of CBCT registration error value and moving bed movement value was defined as the body surface marker line-guided setup error. The sum of CBCT registration error value and the recorded DICOM image RTD value was defined as the theoretical error of DICOM image-guided setup. The advantages and disadvantages of VRT image, body surface marker line and DICOM image-guided setup were compared and analyzed.Results:There were 42 males and 23 females in 65 patients with thoracic tumors, and the age [ M ( Q1, Q3)] was 58 years (51 years, 64 years). The linear errors [ M ( Q1, Q3)] of VRT image-guided setup in X, Y and Z axes were 0.6 mm (0.3 mm, 1.2 mm), 1.2 mm (0.5 mm, 2.4 mm) and 1.1 mm (0.5 mm, 1.9 mm); and the rotational errors were 0.4° (0.1°, 0.7°), 0.4° (0.1°, 0.6°) and 0.4° (0.2°, 0.6°). The linear errors of the marker line-guided setup were 1.6 mm (0.9 mm, 2.6 mm), 2.2 mm (1.1 mm, 3.8 mm) and 1.0 mm (0.4 mm, 1.8 mm); and the rotational errors were 0.7° (0.3°, 1.2°), 0.5° (0.2°, 0.8°) and 0.5° (0.2°, 0.8°). The linear errors of the DICOM image-guided positioning were 1.1 mm (0.6 mm, 1.9 mm), 2.1 mm (1.0 mm, 3.4 mm) and 1.3 mm (0.6 mm, 3.1 mm), and the rotational errors were 0.6° (0.2°, 1.1°), 0.7° (0.3°, 1.1°), 0.7° (0.2°, 1.1°). Compared with the marker line-guided setup, except for Z-axis linear error ( P = 0.218), the VRT-guided setup errors were low (all P < 0.001). Compared with the DICOM imaging-guided setup, the VRT image-guided setup linear error and rotational error in X-, Y- and Z-axis were low (all P < 0.01). Conclusions:VRT image-guided setup is superior to traditional body surface marker setup and DICOM imaging setup; OSMS VRT body surface imaging can effectively improve the setup accuracy and stability of intensity-modulated radiotherapy for thoracic tumors, and reduce the setup errors.
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Objective To investigate the accuracy and application value of optical surface monitoring system in intensity modulated radiotherapy for thoracic tumors patients.Methods Twenty-eight patients with thoracic tumors were included.During each treatment fraction,the patients were immobilized with body surface markers and laser lamps.The surface images obtained by the optical surface monitoring system were registered with the reference images and recorded during the CBCT scan.The translation and rotation errors of x (left-right),y (craniocaudal) and z (anterior-posterior) axes were recorded.After scanning,the CBCT images were registered with the planned CT images and the translation and rotation errors of x,y and z axes were recorded.The setup errors of these two image systems were analyzed and corrected before each treatment.The correlation between the two sets of setup errors were analyzed with Pearson test,and systematic error (∑) and random error (σy) were also calculated.The consistency of the two image systems was evaluated with the Bland-Altman method and the 95％ limits of agreement were calculated.Results There was a good correlation between these two groups,and the correlation coefficients were 0.79,0.62,and 0.53 in x,y and z axes,respectively.The ∑/σr of the optical surface monitoring system were 0.7 mm/1.5 mm,0.9 mm/1.8 mm and 0.9 mm/1.5 mm in x,y and z axes,respectively.The ∑/σ of CBCT were 0.8 mm/1.6 mm,1.3 mm/1.9 mm and 0.7 mm/1.5 mm in x,y and z axes,respectively.The 95％ limits of agreement of translations direction were (-2.0-2.3),(-3.4-3.6) and (-3.3-2.4) mm,and the 95％ limits of agreement of rotation direction were (-2.0 to 1.6)°,(-2.0 to 1.4)° and (-1.6 to 1.6)° inx,y and z axes,respectively.Conclusions The optical surface monitoring system is an effective image guide tool,which can quickly and accurately verify the patient's position and improve the position accuracy.It can be applied for positioning in the intensity modulated radiation treatments for the thoracic tumor patients.
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Objective To analyze the setup errors by cone-beam computed tomography (CBCT) for breast cancer patients who were immobilized with neck and breast thermoplastic mask and received intensity modulated radiation therapy (IMRT), and to calculate the external margins from the clinical target volume (CTV) to the planning target volume (PTV) (MPTV) of tumors. Methods Twenty-five breast cancer patients who were immobilized with neck and breast thermoplastic mask and received IMRT in the Oncology Department of Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from November 2016 to June 2017 were enrolled. The position of the patients were verified by CBCT before treatment . The linear and rotation errors of the X, Y and Z axes were analyzed by online bone registration. The systematic errors (Σ) and random errors (σ) of the patients were also calculated, and then the margins from CTV to PTV margins were calculated based on MPTV=2.5Σ+0.7σ. 25 patients'height, weight, body mass index (BMI) and the maximum diameters of CTV in the lateral, longitudinal and vertical directions were recorded, and the relation between the setup errors and the above mentioned was analyzed by using Spearman method. Results A total of 174 CBCT scans for 25 breast cancer patients were completed. The group Σ were 1.40 mm, 1.50 mm and 1.20 mm, and rotation errors were 0.9°, 0.7° and 0.8° at the X, Y and Z axes, respectively. The group σ were 2.20 mm, 3.00 mm and 1.40 mm, and rotation errors were 0.7°, 0.6° and 0.7° at the X, Y and Z axes, respectively. MPTVwas recommended as 4.90 mm, 6.00 mm and 3.90 mm at the X, Y and Z axes, respectively. There was no correlation between the height, weight, BMI of the patients and the setup errors (all P ＞ 0.05). However, there was a significant correlation between the maximum lateral, longitudinal diameters of the CTV and the setup errors (rs= 0.406, P= 0.044; rs= 0.512, P= 0.009). Conclusions The neck and breast thermoplastic mask can improve the diagnostic accuracy of radiotherapy in breast cancer patients. The data of setup errors verified by CBCT can provide meaningful references for the setting of MPTV.
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This study examined the role of PI3K/Akt pathway in radiosensitization of DNA damage of cervical carcinoma cells. The 50% inhibition concentration (IC(50)) of cisplatin and docetaxel in HeLa cells was detected by Mono-nuclear cell direct cytotoxicity assay (MTT) in vitro. HeLa cells were treated by cisplatin/docetaxel of 10 percent of IC(20) alone or combined with LY294002 for 24 h, and then radiated by different doses of X-ray. The cell survival ratio was obtained by means of clone formation. One-hit multi-target model was fitted to the cell survival curve to calculate dose quasithreshold (Dq), mean lethal dose (D(0)), 2Gy survival fraction (SF(2)) and sensitization enhancement ratio (SER). The pAkt and total Akt expression was detected by Western blotting and DNA damage by neutro-comet electrophoresis. The HeLa cells were randomly divided into 7 groups in terms of different treatments: Control; radiation treatment (RT) group; LY294002+RT group; cisplatin+RT group; docetaxel+RT group; LY294002+cisplatin+RT group; LY294002+docetaxel+RT group. The apoptosis ratio of each group was measured by flow cytometry. The results showed that docetaxel and cisplatin significantly enhanced the phosphorylation of Akt in radiation-treated HeLa cells. The Dq, D(0) and SF2 in LY294002-contained groups were lower than those in docetaxel or cisplatin+RT group. The SER in the LY294002+docetaxel+RT group was 1.35 times that of the docetaxel+RT group, and that in the LY294002+cisplatin+RT group 1.26 times that of the cisplatin+RT group. The Comet electrophoresis showed that tail distance in the LY294002+cisplatin+RT group or LY294002+docetaxel+ RT group was longer than in the cisplatin+RT group or docetaxel+RT group. The apoptosis ratio in the LY294002+cisplatin+RT group or LY294002+docetaxel +RT group was higher than in the cisplatin+RT group or docetaxel+RT group. It was concluded that inhibiting PI3K/Akt pathway can increase the effect of docetaxel and cisplatin on the radiosensitivity of HeLa cells and DNA damage resulted from radiation.