ESTRO 2024 - Abstract Book

S269

Brachytherapy - Gynaecology

ESTRO 2024

heterogeneity of patients, treatments, and reporting. Recently, ESTRO/EORTC published a consensus statement on re-irradiation (3), but the patterns of GRIB reporting have not been analyzed so far. We aimed to assess the patterns of GRIB reporting, summarize the treatment outcomes, and discuss the scope of best practice, based on available evidence.

Material/Methods:

Systematic search of the published literature was performed on PubMed and EMBASE to identify studies on GRIB, published from 1990 to 2023. Information on the following reporting parameters was extracted, reflecting the ESTRO/EORTC consensus statement (3): publication year, study type, patient and tumor characteristics, primary therapy, interval to re-irradiation, therapy for recurrence, brachytherapy (BT) technique, dose rate, fractionation, treatment sum, and clinical outcome.

Results:

We identified 33 retrospective and 3 prospective studies, including a total of 1267 patients. 889(70%) received BT for reirradiation (2). 31(86%) of the reports were published during last decade. Median sample size for all and re irradiated patients was 30 (4-103) and 20 (2-103). 12(33%) authors reported on cervical, 7(19%) on endometrial, and 17(47%) on mixed recurrences, including vaginal, vulvar, and ovarian cancer. Interstitial GRIB with or without intracavitary component was performed by 29(89%) authors. Pure intracavitary GRIB was utilized in selected patients in 4(11%) reports. High- or (very) low-dose rate was the exclusive rate in 19(53%) or 12(33%) reports, while 5(14%) used mixed approaches, including pulsed-dose rate in one series. We found a wide variation of the administered GRIB doses and schedules, which were individualized, based on the dose during first treatment and, in some studies, cumulative organ at risk (OAR) doses and existent late side effects. Dose specification, when reported, varied between point-based in 8(22%), volume-based in 19(53%), and mixed in 4(10%) of the series. Patterns of recording and reporting are presented in Table 1. Only one study mentioned persistent late side effects from primary treatment (2). 23(64%) authors specified the median interval from the primary course to re irradiation. Intent (palliative vs. curative) was specified in 6(17%) of reports. Only 10(28%) studies gave indication of the target planning aims, 8(22%) specified the OAR dose constraints, and 14(39%) reported on cumulative doses. Local control and side effects were reported in ~90%. However, the follow-up method and the system for side effect assessment were indicated only in 12(33%) and 20(56%) of publications. None of the authors reported on the quality of life. The re-irradiation type was implicitly reported in all published series.: most central pelvic recurrences which can be treated with GRIB meet criteria of type 1 re-irradiation (3). After a median follow-up of 1-5 years, the local control rates were around 70-90% at 1 year, 45-70% at 3 years, and 45-70% at 5 years. Respective overall survival rates were around 80%, 50-70%, and 40%. Late G3-4 toxicity ranged from 0% to 43% (2).