Evaluation of brachytherapy applicators and their association with morbidity and local control in cervix cancer: An EMBRACE I analysis.

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All Authors

Serban, M.
Spampinato, S.
de Leeuw, A.
Fortin, I.
Kirisits, C.
Ye, XY.
Schmid, M.
Hoskin, P.
Mahantshetty, U.
Segedin, B.

LTHT Author

Cooper, Rachel

LTHT Department

Oncology
Leeds Cancer Centre

Non Medic

Publication Date

2025

Item Type

Journal Article
Multicenter Study

Language

Subject

Subject Headings

Abstract

PURPOSE: To investigate the effects of brachytherapy (BT) applicator and implant type on morbidity and local control (LC) in locally advanced cervix cancer patients. METHODS: 1071 patients treated with radiochemotherapy including MRI-guided BT using tandem&ring (T&R) or tandem&ovoids (T&O) from 19 EMBRACE-I centers were analyzed. Intracavitary (IC) or intracavitary/interstitial (IC/IS) implants were used. Centers came from different brachytherapy traditions and followed their institutional dose aims and planning strategies. LC and physician-assessed morbidity (median follow-up 48 months) was compared between applicator/implant types using Cox proportional hazard model adjusting for patient characteristics and treatment-related potential confounders. Moderate-to-severe (G >= 2) genito-urinary (cystitis/frequency/incontinence), gastro-intestinal (proctitis/bleeding/diarrhea) and vaginal (stenosis/mucositis) symptoms were analysed individually. Severe events (G >= 3) were pooled per organ. RESULTS: The T&O (n = 346) compared to T&R (n = 725) had a higher risk of morbidity, with HRs > 1.3 in 14/16 individual G >= 2 symptoms and in 3/4 G >= 3 pooled organ symptoms. Patients treated with IC/IS (n = 512) compared to IC (n = 559) were not at higher risk of G >= 2 symptoms, with HRs < 1 in 6/8 MVAs. Crude incidence of local failure was 7.3 % (25/343) for T&O and 6.6 % (47/712) for T&R. CONCLUSIONS: In this patient cohort, treated between 2008-2015, T&R and T&O demonstrated comparable LC. However, a higher risk of morbidity is reported for T&O. This increased risk was partly explained by hotspot doses, with factors such as irradiated volumes and organ irradiation length also contributing. Additionally, implant quality, dose planning aims and strategies, and morbidity reporting may have impacted the observed differences in morbidity. IC/IS applicators did not increase morbidity risk compared to IC applicators.

Journal

Radiotherapy & Oncology