Salas Juan Carlos Pari, Urviola Kevin Aguirre, Benavides Paola Cynthia Smith, Flores Digna Cristina Santos, Cruz Albert Bedregal, Véliz Danny Giancarlo Apaza
Universidad Católica de Santa María, Arequipa, Perú.
Servicio de Radioterapia-Hospital Goyeneche de Arequipa, Perú.
J Contemp Brachytherapy. 2025 Feb;17(1):15-21. doi: 10.5114/jcb.2025.147944. Epub 2025 Feb 24.
In cervical cancer, brachytherapy is a key component of multi-disciplinary treatment. Wide scale studies, such as EMBRACE, demonstrate benefits of volume-oriented and image-guided brachytherapy. However, MRI and CT are too expensive for health systems with scarce resources. The aim of the study was to assess whether ultrasound- and CT-based volumes of high-risk clinical target volume (HR-CTV) in organs at risk (OARs) as well as dose values in a given plan are comparable.
Eighteen applications were evaluated. After CT scans, axial ultrasound images were acquired in 5 mm steps, serving as a secondary set. Post-prescription, HR-CTV, bladder, and rectum were contoured on ultrasound images. Image sets were compared using CT-based volumes as primary reference. Dice coefficient and Jaccard index were calculated. CT-based dosimetric plan was then compared with ultrasound-based volumes to determine D HR-CTV, D bladder, and D rectum, and these were compared with CT-based values.
The mean dose differences between CT and ultrasound volumes for HR-CTV and D rectum were less than 5%, with the bladder slightly above 5%. Wilcoxon test showed no significant difference between the mean doses for CT and ultrasound. Dice coefficients indicated good to very good correlation for these volumes.
Ultrasound-based volume acquisition appears comparable with CT volumetric acquisition in both dosimetric and volumetric terms. Further studies are needed to validate this technique, potentially offering a more affordable and feasible volume-based brachytherapy option for low-income health systems.
在宫颈癌治疗中，近距离放射治疗是多学科治疗的关键组成部分。诸如EMBRACE等大规模研究证明了体积导向和图像引导近距离放射治疗的益处。然而，对于资源稀缺的卫生系统而言，MRI和CT成本过高。本研究的目的是评估基于超声和CT的高危临床靶区（HR-CTV）在危及器官（OARs）中的体积以及给定计划中的剂量值是否具有可比性。
评估了18例应用。CT扫描后，以5mm步长采集轴向超声图像，作为第二组图像。处方后，在超声图像上勾勒出HR-CTV、膀胱和直肠的轮廓。以基于CT的体积作为主要参考，比较图像集。计算Dice系数和Jaccard指数。然后将基于CT的剂量计划与基于超声的体积进行比较，以确定D HR-CTV、D膀胱和D直肠，并将这些与基于CT的值进行比较。
HR-CTV和D直肠的CT与超声体积之间的平均剂量差异小于5%，膀胱略高于5%。Wilcoxon检验显示CT和超声的平均剂量之间无显著差异。Dice系数表明这些体积之间具有良好到非常好的相关性。
基于超声的体积采集在剂量学和体积方面似乎与基于CT的体积采集具有可比性。需要进一步研究来验证该技术，这可能为低收入卫生系统提供一种更经济可行的基于体积的近距离放射治疗选择。
