Prostate volumes and organ movement defined by serial computerized tomographic scans during three-dimensional conformal radiotherapy

作者：Mack Roach, Pamela Faillace-Akazawa, Christine Malfatti · 发表于：Radiation Oncology Investigations · 年份：1997 · DOI：10.1002/(sici)1520-6823(1997)5:4<187::aid-roi4>3.0.co;2-u · 被引用次数：62 · 研究领域：Advanced Radiotherapy Techniques、Prostate Cancer Diagnosis and Treatment、Medical Imaging Techniques and Applications

The aim of this study was to assess changes in prostate volumes and organ movement during a course of external beam irradiation using serial computerized tomographic (CT) scans and three-dimensional treatment planning software. Ten consenting prostate cancer patients underwent repeat CT scans at biweekly intervals during the course of external beam irradiation. The spacing of 5 mm was used because this spacing mimics our clinical treatment approach. Prostate locations were determined by merging CT images using bony anatomy and comparing the differences in the prostate volumes, the edges (anterior, posterior, superior, inferior, and lateral) and centers of the prostate (EoP and CoP, respectively). Compared to the 10 initial treatment planning CT scans, the prostate volume determined by the repeat CT scans tended to be smaller (approximately 14%, P < 0.001). The prostate volumes determined by repeat CT scans tended to be stable with a mean volume of 86% (S.D. = 18%) of the initial CT. When assessed by changes in the EoP, superior movements appeared to be the most common source for concern for adequate coverage of the prostate, while inferior movement was not seen. When assessed by changes in CoP, movement of > or = 3 mm was noted in 47% of the studies in the superior direction, with the average displacement being approximately 2.0 mm. In this study, the prostate volume tended to be smaller 2 weeks after the start of radiotherapy. Moreover, the prostate volumes defined by the se...