CT-guided hydrogel injection for brachytherapy in cervical cancer: A case report

Rectal toxicity is a significant concern in cervical cancer radiotherapy. Despite advancements in image-guided brachytherapy (IGBT), rectal morbidity remains a challenge. Injectable hydrogel showed promise in creating a space between the vagina and rectum, reducing rectal radiation dose; however, the traditional ultrasound-guided injection revealed some problems, such as the inadequate separation of the upper edge of the cervix, which can be mitigated through adopting CT-guided injection. This case report presents the successful use of computed tomography (CT)-guided hydrogel injection to limit rectal doses and improve treatment outcomes. A forty-year-old female with stage IIIC1r cervical cancer received external-beam radiotherapy and concurrent chemotherapy. Due to the proximity of the tumor to the rectum, a CT-guided hydrogel injection was performed to increase the distance between the cervix and rectum. Post-injection, magnetic resonance imaging (MRI) demonstrated increased distances between the cervix and rectum. Subsequent MRI-based IGBT achieved high clinical target volume doses while limiting rectal doses. During the six-month follow-up, the patient reported only mild adverse effects. CT-guided hydrogel injection offers advantages over ultrasound-guided injection in cervical cancer radiotherapy. The technique allows for better puncture position adjustment, reduced reliance on specialized ultrasound expertise, and shorter puncture distances. This case report highlights the potential of hydrogel injection as a viable method to reduce rectal morbidity and improve treatment outcomes in a broader range of cervical cancer patients. Further studies are warranted to validate these findings and explore its applicability in larger cohorts.