ESTRO 2024 - Abstract Book

S208

Brachytherapy - Gynaecology

ESTRO 2024

130

Digital Poster

Treatment outcomes of MRI-guided adaptive brachytherapy in patients with advanced cervical cancer

Radovan Vojtíšek 1 , Petr Hošek 2 , Emília Sukovská 1 , Petra Kovářová 1 , Jan Baxa 3 , Jiří Ferda 3 , Jindřich Fínek 1

1 Charles University in Prague, Faculty of Medicine and University Hospital in Pilsen, Department of Oncology and Radiotherapy, Pilsen, Czech Republic. 2 Charles University in Prague, Faculty of Medicine in Pilsen, Biomedical Center, Pilsen, Czech Republic. 3 Charles University in Prague, Faculty of Medicine and University Hospital in Pilsen, Department of Imaging Methods, Pilsen, Czech Republic

Purpose/Objective:

Image guided adaptive brachytherapy (IGABT) is currently state-of-the-art in the comprehensive treatment of patients with cervical cancer. At our institution, IGABT based on MRI has been in place since 2012. Here we report mature clinical data regarding IGABT of cervical cancer in a large patient sample, examining clinical outcomes, manifestations of late toxicities, and also dosimetric findings.

Material/Methods:

Between May 2012 and October 2020, we performed a total of 544 uterovaginal IGABT applications in 131 consecutive patients with biopsy-proven cervical carcinoma not suitable for surgery. The median duration of follow-up was 43 months. The following parameters have been investigated: overall treatment duration, the volume of HR-CTV, total D90 in HR-CTV, D2cm3 for rectum, sigmoid and bladder, clinical outcomes in terms of local control (LC), nodal control (NC), pelvic control (PC), recurrence-free survival (RFS), OS, and manifestations of late gastrointestinal (GI) and genitourinary (GU) toxicity according to the Common Terminology Criteria for Adverse Events (CTCAE v5.0)

Results:

One hundred and nineteen patients (90.8 %) achieved locoregional remission after the treatment, evaluated according to pelvic MRI or PET/MRI performed at least 3 months after the end of RT. In 110 patients (84 %) the remission was complete, whereas 9 patients (6.8 %) reached partial locoregional remission. Twelve patients (9.2 %) progressed in distant regions. We have observed a relapse of the disease in 32 patients (24.4%), isolated local recurrence was present in 4 patients (3.1 %), isolated relapse in PALN in one patient (0.8 %), distant recurrence in 13 patients (9.9 %) and various combinations of the relapses in 14 patients (10.7 %). The estimated 3-, 4- and 5-year LC rates were 88.3% (95% confidence interval [CI] 81.1 - 95.5), 86.9% (95% CI 78.5 - 95.3), and 85.5% (95% CI 76 - 95%), respectively. The 3-, 4- and 5-year OS estimates were 72.66 % (95% CI 63.64 - 81.69%), 68.9% (95% CI 59.15 - 78.66%), and 63.96% (95% CI 52.94 - 74.97 %), respectively. Patients who received ≥ 5 cycles of chemotherapy had statistically significantly better 3-year recurrence-free survival (RFS) compared to patients who completed <5 cycles (79.07% [95% CI 60.81 – 97.34] vs. 58.10% [95% CI 47.22 – 68.98]; p=0.0185). We recorded manifestations of GU and GI toxicity grade ≥ 3 in 6.9% and 5.3%, respectively.

Conclusion: