Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara-cho, Nakagami-gun, Okinawa 903-0215, Japan.
Division of Radiology, University of the Ryukyus Hospital, 207 Uehara, Nishihara-cho, Nakagami-gun, Okinawa 903-0215, Japan.
J Radiat Res. 2024 Sep 24;65(5):689-692. doi: 10.1093/jrr/rrae055.
Intracavitary brachytherapy with a remote after-loading system (RALS) is performed as a part of radical radiation therapy in cervical cancer. The radiation source is delivered directly through an applicator placed inside the uterus or vagina. Thorough quality control is important to prevent accidents that can lead to serious irradiation error, and an applicator check is one such quality control measure. We experienced a clinical situation in which a small volume of water was observed in the lumen of a post-sterilized applicator on treatment-planning CT. Although the submersion test was negative and no air bubbles emerged from the applicator, ultra-high-resolution computed tomography (U-HRCT) showed a linear crack reaching the inside of the applicator. This abnormality was not identified on treatment-planning CT, which has lower spatial resolution than U-HRCT. In addition, no linear cracks were seen on U-HRCT images of eight other applicators considered to be free from damage. U-HRCT may have superior potential to detect applicator damage and could be useful for quality assurance of the RALS procedure.
腔内近距离放射治疗（RALS）是宫颈癌根治性放射治疗的一部分。辐射源通过放置在子宫或阴道内的施源器直接输送。为了防止可能导致严重放射误差的事故，彻底的质量控制非常重要，施源器检查就是这样一种质量控制措施。我们遇到了一种临床情况，在治疗计划 CT 上观察到一个经过消毒的施源器管腔内有少量水。虽然浸没法测试为阴性，并且施源器没有气泡冒出，但超高分辨率计算机断层扫描（U-HRCT）显示有一条线性裂缝一直延伸到施源器内部。这种异常在治疗计划 CT 上没有被识别出来，因为它的空间分辨率低于 U-HRCT。此外，在 U-HRCT 图像上也没有看到其他 8 个被认为没有损坏的施源器有线性裂缝。U-HRCT 可能具有更高的检测施源器损坏的潜力，可用于 RALS 程序的质量保证。
