ESTRO 2024 - Abstract Book

S1107

Clinical - Gynaecology

ESTRO 2024

The combination of external beam radiotherapy (with concomitant chemotherapy) and brachytherapy remains the standard of care for locally advanced cervical cancer. However, our study demonstrates that an IMRT boost with a total dose of 20Gy to 24GY (2GY/FR) could be a reasonable option when brachytherapy is not possible .

Keywords: IMRT, cervical cancer, boost

2896

Digital Poster

Correlation between MR-Radiomics and Outcomes after Concurrent Chemoradiation in Cervical Cancer

Pitchayut Wongsuwan 1 , Wiwatchai Sittiwong 1 , Pittaya Dankulchai 1 , Tissana Prasartseree 1 , Wajana Thaweerat 1 , Nerisa Thornsri 2 1 Faculty of Medicine Siriraj hospital, Radiology, Bangkok, Thailand. 2 Faculty of Medicine Siriraj hospital, Research, Bangkok, Thailand

Purpose/Objective:

The outcome of concurrent chemoradiation in combination with 3D-image guided adaptive brachytherapy (3D IGABT) for locally advanced cervical cancer was favorable. However, there are still significant rates of relapses. Several tools have been proposed to predict the treatment outcomes. Radiomics is a study that can provide unseen information in the images which could be a potential predictive tool to predict the prognosis of the patients. The objective of this study was to determine the correlation between radiomic features of the pre treatment (PreRx), pre-brachytherapy (PreBT), radiomic feature shift (difference of PreRx and PreBT: Diff) and oncological outcomes after concurrent chemoradiation in patients with locally advanced cervical cancer.

Material/Methods:

Between January 2016 and December 2021, 75 patients with locally advanced cervical cancer patients with histologic subtype of squamous cell carcinoma, adenocarcinoma or adenosquamous carcinoma were included in the study. The eligible patients must receive definitive concurrent chemoradiation IMRT or VMAT technique in combination with weekly cisplatin or carboplatin followed by 3D-IGABT. Complete pre-treatment and pre brachytherapy MRI were mandatory. Contouring on MR images for gross tumor volume of the primary tumor (GTVp) and lymph node (GTVn) was performed. All contoured MR images including T2W, DWI and ADC series were imported to MIM software and first-order radiomic data computed by the software were exported for the analysis. The rates of local control, nodal control, distant metastasis-free survival, and overall survival were analyzed by Kaplan-Meier method. Chi-square test and Mann Whitney-U test were assessed to compare differences in clinical, radiomics features and oncologic outcomes. Forward elimination method was used in Cox-Regression Analysis to prove the factors associated between oncologic outcomes and radiomics features including PreRx, PreBT and Diff. A p-value less than 0.05 is considered as statistical significance.

Results:

The median follow-up time was 24.5 months. According to FIGO 2018 staging, patients were mainly diagnosed as stage IIIB (34 patients, 45.3%) and IIB (26 patients, 34.7%). For nodal staging, most patients were N1 (32 patients,