Risk factors for venous thromboembolism induced by prolonged bed rest during interstitial brachytherapy for gynecological cancer: a retrospective study

Considerations for pharmacologic thromboprophylaxis following inpatient brachytherapy for gynecologic malignancies

PURPOSE

Brachytherapy irradiation carries risks of both bleeding and venous thromboembolism (VTE). No screening or management recommendations for VTE in this setting have been developed. Our study aims to understand the incidence of VTE, compile published anticoagulation guidelines, and call for future guidelines to address thromboprophylaxis in this population.

METHODS AND MATERIALS

A retrospective, single institution study of patients undergoing brachytherapy irradiation between 2012 and 2022 was undertaken. We analyzed 2 cohorts: 87 patients undergoing brachytherapy with an inpatient admission, and 66 patients assessed for risk of VTE or bleeding after discharge from an inpatient admission for brachytherapy. Caprini risk scores were calculated for each patient, and statistical analyses were performed.

RESULTS

Eighty-seven patients were included, and 25% had a VTE diagnosis. Forty-seven (54%) of patients included underwent brachytherapy as definitive treatment of cervical cancer, and 16 (18%) received brachytherapy irradiation to treat recurrent endometrial cancer. In the cohort of 66 patients assessed for risk of VTE or bleeding after brachytherapy discharge, 23 (34.8%) were discharged with thromboprophylaxis, and 43 (65.2%) were discharged without thromboprophylaxis. None of the patients discharged on thromboprophylaxis were diagnosed with a VTE within 90 days of discharge after brachytherapy, whereas 3 of 43 (7%) discharged without thromboprophylaxis were diagnosed with a VTE, OR and 95% CI: 0.25 (0.01-5.29), p = 0.37. Of the 23 patients discharged on thromboprophylaxis, 1 was readmitted for bleeding OR and 95% CI: 5.8 (0.22-155.18), p = 0.29. The median Caprini score was 11.

CONCLUSIONS

VTE is a common occurrence in patients undergoing brachytherapy. Patients undergoing brachytherapy irradiation who require inpatient admission represent a unique population, and specialty organizations should develop consensus recommendations to address these clinical challenges.

Outcomes of 3D MRI based HDR brachytherapy with hybrid multichannel vaginal cylinder applicator and freehand needles for treatment of vaginal disease

Freehand needles can be used with multichannel vaginal cylinders (MCVC) to cover vaginal cancer >7 mm thick or with supra-vaginal extension. We report our institutional outcomes using this novel hybrid technique. Patients with vaginal malignancies treated with HDR BT using MCVC plus freehand needles from 2014-2021 at our institution were identified. Clinical characteristics, details of brachytherapy, initial response, and overall local control (LC) outcomes were recorded. LC was analyzed via Kaplan-Meier method. 34 patients were identified with median follow-up 1.9 years. 19 patients had primary endometrial cancer with vaginal recurrence/disease, and remaining had primary vaginal cancer or other primaries. 7 patients had recurrence after previous RT course. 25 patients received EBRT with median dose 45 Gy in 25 fractions, and rest received BT alone. Median HR-CTV D90 for patients treated with EBRT plus BT was 77.4 Gy. 30 patients had complete local response to BT on initial examination and/or follow-up imaging. 1 and 2-year LC rates in patients without prior RT treated with EBRT + BT were 94.1% and 94.1%, respectively. 1 and 2-year LC rates for those without prior RT were 88.1% and 76.4%, respectively. 1 and 2-year LC rates for those with prior RT were 68.6% and 34.3%, respectively. 1 patient had vaginal laceration requiring surgical repair, and 1 patient developed small bowel obstruction 1 month after BT, with no additional acute grade 3+ toxicities identified. Our approach with MCVC plus freehand needles with MRI-based planning was feasible and safe, with excellent initial local response and low rate of serious toxicities.