Dosimetric analysis of ultrasound-guided radiotherapy for prostate cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2026年第2期
- Page:
- 155-161
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric analysis of ultrasound-guided radiotherapy for prostate cancer
- Author(s):
- CHENG Jianqiang; LI Fengju; ZHAO Fengju; NIU Ruijun; WEI Xiyi; TAO Na; JIA Huailin; LU Yaqiong; ZHANG Chunlin; DONG Fang
- Department of Radiation Oncology, Gansu Provincial Cancer Hospital, Lanzhou 730050, China
- Keywords:
- prostate cancer radiotherapy ultrasound-guided dosimetry
- PACS:
- R318；R815
- DOI:
- DOI:10.3969/j.issn.1005-202X.2026.02.003
- Abstract:
- Abstract: Objective To analyze the differences in irradiation doses delivered to target areas and organs-at-risk (OAR) during interfraction and intrafraction treatments of ultrasound-guided radiotherapy for prostate cancer. Methods A retrospective analysis was conducted on 36 prostate cancer patients admitted to Department of Radiation Oncology, Gansu Provincial Cancer Hospital from 2020 to 2024. According to ultrasound guidance modalities, they were divided into interfraction guidance with three-dimensional ultrasound and intrafraction guidance with four-dimensional real-time ultrasound. The doses received by target areas and OAR were analyzed in relation to different setup errors. Results The maximum and minimum setup errors in 451 interfractions guided by three-dimensional ultrasound were 5.8 mm and 4.8 mm, respectively, and the setup errors along the X-, Y-, and Z-axes were (-0.31±2.50), (0.48±2.39), and (-0.12±2.02) mm, respectively, without significant inter-axis differences (P>0.05). The minimum prostate setup error in the 45 intrafractions guided by four-dimensional real-time ultrasound was 0.1 mm. In terms of three-dimensional setup errors, the maximum values were 2.8 mm (Right), 2.6 mm (Left), 3.2 mm (Inferior), 2.4 mm (Superior), 1.9 mm (Posterior), and 1.6 mm (Anterior), respectively while the average values were 1.2 mm (Right), 1.1 mm (Left), 1.6 mm (Inferior), 1.2 mm (Superior), 1.2 mm (Posterior), and 1.5 mm (Anterior), respectively. The setup errors along the X-, Y-, and Z-axes were (0.21±2.30), (-0.36±2.15), and (-0.18±2.07) mm, respectively, without significant inter-axis differences (P>0.05). For varying three-dimensional displacements, displacements exceeding 3 mm significantly affected the dose coverage of the target areas, whereas displacements over 2 mm exerted a remarkable effect on the gamma passing rate 3 mm/3% of the treatment plan, with passing rates below 95%. The head-foot directional deviations had a significant effect on the irradiation doses delivered to the bladder and pelvic bones, whereas the anterior-posterior directional deviations had a pronounced effect on the rectal dose. No significant difference was observed in the three-dimensional penis dose. Conclusion The analysis of the radiation doses delivered to the target areas and OAR in ultrasound-guided radiotherapy for prostate cancer shows that prostate displacement within 3 mm rarely affects the prescription dose coverage in the target area and the exposure to the OAR, while the displacement exceeding 3 mm results in significant reduction in prescription dose coverage in the target areas, and statistically significant differences in radiation doses received by the OAR. This study provides certain reference significance for clinicians to determine the target area margins.
Last Update: 2026-01-27