Implementation of image-guided brachytherapy as part of non-surgical treatment in inoperable endometrial cancer patients

OBJECTIVE

This study assessed outcomes of inoperable endometrial cancer (IEC) patients treated with definitive external beam radiation therapy (EBRT) followed by a 3D image-guided brachytherapy boost.

METHODS

All consecutive patients treated with EBRT followed by 3D image-guided brachytherapy for IEC were retrospectively included. EBRT delivered a dose of 45Gy. Then, patients had an uterovaginal brachytherapy guided by 3D imaging. Clinical target volume (CTV_BT) included the whole uterus and the initial disease extent. Gross tumour volume (GTV_res) included the residual disease at time of brachytherapy.

RESULTS

Twenty-seven patients were identified. Causes of inoperability were comorbidities (37%) or tumour loco regional extent (63%). Including EBRT and brachytherapy, the median D₉₀ (minimal dose delivered to 90% of the volume) was 60.7 Gy_EQD2 (IQR = 56.4-64.2) for the CTV_BT, and was 73.6 Gy_EQD2 (IQR = 64.1-83.7) for the GTV_res. The median overall treatment time was 50 days (IQR = 46-54). The mean follow-up was 36.5 months (SD = 30.2). The cumulative incidence of local, pelvic and distant failures was 19% (n = 5), 7% (n = 2) and 26% (n = 7), respectively. Five-year overall survival was 63% (95% CI = 43-91). Late urinary and gastro intestinal toxicities ≥ grade 2 were reported in four (15%) and two patients (7%) respectively. No vaginal toxicity ≥ grade 2 was reported.

CONCLUSIONS

EBRT followed by intracavitary brachytherapy seems to be an effective option for IEC. The implementation of 3D concepts at time of brachytherapy may contribute to high local control probability and low toxicity profile. Large scale retrospective or prospective data are needed to confirm these early data.

Pulsed-Dose Rate Brachytherapy for the Treatment of Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecologic malignancy. The aim of this review is to outline clinical practice recommendations, to suggest a technical solution, and to advise doses selection for pulsed-dose rate (PDR) brachytherapy in EC. Electronic bibliographic databases, including PubMed, clinicaltrials.gov, and the American Society of Clinical Oncology (ASCO) Meeting Library, were searched for articles in English. Clinical guidelines and systematic reviews were also considered. The appropriate therapeutic approach should consider risk factors for tumor relapse and PDR brachytherapy and have a convincing role in this multidisciplinary scenario. Performing PDR brachytherapy in EC requires robust training and experience.

[Pulsed-dose rate brachytherapy in cervical cancers: why, how?]

The end of the production of 192 iridium wires terminates low dose rate brachytherapy and requires to move towards pulsed-dose rate or high-dose rate brachytherapy. In the case of gynecological cancers, technical alternatives exist, and many teams have already taken the step of pulsed-dose rate for scientific reasons. Using a projector source is indeed a prerequisite for 3D brachytherapy, which gradually installs as a standard treatment in the treatment of cervical cancers. For other centers, this change implies beyond investments in equipment and training, organizational consequences to ensure quality.