CT-Guided Placement of a Polyethylene Glycol Hydrogel in Brachytherapy for Gynecologic Malignancy to Limit Nontarget Organ Toxicity

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.

SpaceOAR hydrogel spacer in interstitial brachytherapy for intrapelvic recurrent endometrial cancer: a case report

Objective:

We report the use of SpaceOAR hydrogel spacer in interstitial brachytherapy (ISBT) for a patient with intrapelvic recurrent endometrial cancer (EC).

Methods and materials:

A 59-year-old female patient was diagnosed with intrapelvic recurrence of EC after a definitive surgery. Despite administration of adjuvant chemotherapy, the recurrent tumour in the right para-rectal fossa increased in size. Salvage radiotherapy, including external beam radiotherapy followed by ISBT boost, was planned. We planned to inject SpaceOAR between the tumour and rectum to reduce the rectal dose in ISBT; transrectal ultrasound-guided SpaceOAR injection was performed using needle applicator insertion. This was followed by computed tomography-based image-guided brachytherapy.

Results:

The use of SpaceOAR allowed us to achieved both a higher dose for the clinical target volume and a lower dose for the rectum. Furthermore, no ISBT-related complications or acute toxicities were observed.

Conclusions:

The preliminary results suggest that SpaceOAR could be effective in increasing the efficacy of ISBT for intrapelvic recurrent EC, while reducing the associated complications.

Complications of intracavitary brachytherapy for gynecologic cancers and their management: A comprehensive review

Intracavitary gynecologic brachytherapy in the form of tandem-based brachytherapy and vaginal cylinder-based brachytherapy represents a fundamental component of the treatment of women with cervical or uterine cancer due to the ability to deliver a therapeutic dose of radiation with sharp dose falloff. This results in highly effective treatment in terms of oncologic outcomes with an overall favorable toxicity profile. Still, complications and side effects of brachytherapy do exist. While advances in brachytherapy techniques have led to a significant decrease in the rates of toxicity, a thorough understanding of the potential complications is crucial to ensuring optimal outcomes for women with gynecologic cancer undergoing brachytherapy. Use of equivalent dose at 2 Gy per fraction (EQD2) models has allowed incorporation of external beam radiotherapy dose to the brachytherapy dose leading to development of consolidated dose constraints for organs-at-risk in the modern era. This manuscript offers a comprehensive review of potential complications associated with intracavitary brachytherapy for gynecologic cancer including predictive factors, mitigation tactics, and management strategies.