Author: Olubunmi Odunola Aregbe, Clara Ferreira, Margaret Reynolds, David A. Sterling, Jianling Yuan 👨🔬
Affiliation: University of Minnesota, University of Minnesota Physicians, Department of Radiation Oncology, University of Minnesota, Minneapolis 🌍
Purpose: To analyze volume changes in the high-risk clinical target volume (HR-CTV) during high-dose rate (HDR) brachytherapy for cervical cancer patients. The study aims to evaluate the trend and correlation of these volume changes to determine whether a new target for every treatment fraction is needed to ensure optimal dose delivery and patient safety.
Methods: In this retrospective study of 15 cervical cancer patients treated with the tandem and ring applicator, the HR-CTV were collected for each of the five fractions. The segmented volumes were extracted from anonymized MRI DICOM RT plan files using the 3D Slicer. Statistical analysis was conducted to assess volume changes from the first fraction and identify correlations across fractions.
Results: On average, across all 15 patients, the mean variation in volume was 10.3% with a standard deviation of 19.9%. The maximum observed percentage difference in HR-CTV between fractions was 64.5%, while the minimum was 2.9%. The high standard deviation is largely driven by patients with substantial percentage differences, as 86.6% of the patients exhibit differences exceeding 5% variability between treatment fractions.
Conclusion: This study highlighted the variability in HR-CTV during HDR brachytherapy for cervical cancer patients. The results emphasize the importance of personalized treatment evaluation, particularly for patients with noticeable volume changes, to account for anatomical and physiological changes, ensuring optimal dose delivery and improved patient safety during HDR brachytherapy.