Objective: To study the effect of 60Co-γ ray irradiation on the contents of danshensu,protocatechuic aldehyde,puerarin and salviamolic acid B in Tongmai granules by HPLC. Methods: An Agilent ZORBAX Eclipse XDB C18(2) column (250 mm × 4. 6 mm,5 μm) was adopted and the wavelength of UV detection was 280 nm at the flow rate of 1. 0 ml·min-1. The mobile phase consisted of 0. 1% phosphoric acid (B) and acetonitrile (A) with gradient elution, and the column temperature was 35℃. Tongmai granules were irradiated by 60Co-γ ray respectively at 0, 2, 5,10 and kGy,the contents of the active ingredients were compared before and after the irradiation. Results: The linear range of danshensu,protocatechuic aldehyde,puerarin and salviamolic acid B was 0. 098-4. 925 μg, 0. 028-1. 411 μg, 0. 378-18. 882 μg and 0. 218-10. 888 μg, respectively. The average recovery was 99. 8% , 97. 7% , 99. 9% and 99. 9% , respectively. When the radiation dose was not more than 2 kGy, the contents of the five components did not change significantly (P>0. 05). After 5 kGy radiation, the contents of protocatechuic aldehyde and salviamolic acid B were signifi-cantly different (P <0. 05). Conclusion: The dose of 60Co ray should be controlled not more than 2 kGy, and the sterilization method is safe and effective for Tongmai granules.

Objective:To reconstruct the dose of nasopharyngeal carcinoma and verify the results of the whole-process radiotherapy plan based on log files and cone beam CT (CBCT).Methods:A total of 15 patients with nasopharyngeal carcinoma who received volumetric modulated arc therapy (VMAT) with Halcyon accelerator in the Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from February to September 2022 were retrospectively selected. Log files and CBCT for all fractionated radiotherapy were recorded. The errors of monitor unit (MU), gantry angle, and multi-leaf collimator (MLC) leaf position per control point were analyzed. The adaptive CT (aCT) were generated according to CBCT and planned CT (pCT) using a commercial software Velocity TM, and the similarities among aCT, pCT and CBCT were analyzed. The original plan was modified from the log files and imported into the treatment planning system to calculate the delivered dose on the corresponding fractionated aCT to reconstruct the fractionated dose. And all the reconstructed doses were mapped back to pCT to obtain the cumulative dose. Theγpass ratios with criteria of 2 mm/2% and 2 mm/3% and the dose differences between the planned dose and the cumulative dose in the planning target volume (PTV) and organs at risk (OAR) were compared. Results:The root mean square (RMS) and the 95th percentile of the errors of MU, gantry angle and MLC leaf position errors were within an acceptable range. The aCT generated by Velocity TM had the anatomical structure of CBCT and the resolution, contrast, noise characteristics of pCT, which could be directly used for dose calculation. Compared with the planned dose, the changes of V 70 Gy of nasopharyngeal primary tumor (PTV nx), V 68 Gy of cervical glands (PTV nd) and V 60 Gy of planning target volume (PTV1) were -0.88%±1.91%, -2.99%±2.99% and -0.63%±0.93%, respectively, and V 40 Gy of parotid gland was increased to 2.65%±2.63%. Cumulative dose showed different degrees of PTV dose decrease ( P<0.05) and parotid dose was increased ( P<0.05). The γ pass ratio (2 mm/3%) between the cumulative dose and planned dose was 97.3%±2.7% and >95.0% in 86.7% of patients. Conclusions:Based on the log files and CBCT, the whole-process dose reconstruction of nasopharyngeal carcinoma patients can be carried out. According to the results of dose reconstruction, the radiotherapy effect of the target area and OAR can be quantitatively evaluated. In the case of high dose coverage and conformity of the original plan, the reconstruction results show that the cumulative dose coverage of the target area is decreased, whereas that of the parotid gland is increased.