ESTRO 2024 - Abstract Book

S1098

Clinical - Gynaecology

ESTRO 2024

This study aims to evaluate the feasibility of ERI in predicting local control (LC) after cisplatinum-based chemotherapy and external beam radiotherapy (CRT) followed by brachytherapy in locally advanced cervical cancer (LACC), starting from T2-WI and apparent diffusion coefficient (ADC) maps.

Material/Methods:

Ninety-one patients with LACC (FIGO IB3-IVA) underwent MRI for staging and after CRT. GTV was delineated on the axial oblique T2-WI and ADC map and ERI was calculated on both sequences. Response to CRT and brachytherapy was evaluated six months after the end of treatment using MRI and PET/CT exams. LC was considered in case of the absence of residual disease.

The ERI performance was quantified by calculating the area (AUC) under the Receiver Operating Characteristic (ROC) curve and measuring sensitivity and specificity at the best threshold value.

Results:

The ROC curves obtained for ERI calculated on T2 (ERIT2) and ADC (ERIADC) are reported in Figure 1. The performance of ERIT2(AUC=0.84; 95% CI 0.76-0.95) was superior to that reported by ERIADC (AUC=0.72; 95% CI 0.63-0.81). At the best cut-off threshold, ERIT2 showed excellent specificity (100.0%) with limited sensitivity (67.4%), while ERIADC showed high specificity (87.2%) and low sensitivity (59.1%). At subgroup analysis, both ERIT2 and ERIADC showed lower accuracy in adenocarcinoma (72.3% and 70.4%) compared to squamous subgroup (87.5% and 81.3%)

Conclusion:

ERI is a promising biomarker in LACC treated with concurrent CRT. Combining ERIT2 and ERIADC, it is possible to identify poor responders after CRT thus modulating the brachytherapy boost consequently.

Keywords: Cervical Cancer, ERI, Response

2726

Digital Poster

Moderately hypo-fractionated radiotherapy with concurrent chemotherapy for cervical carcinoma

Shreya Singh, Manav Shah, Uday Pratap Shahi, Isha Jaiswal, Himanshu Mishra, Ritusha Mishra, Chandra Prakash

Institute of Medical Sciences, B.H.U., Department of Radiotherapy and Radiation Medicine, Varanasi, India

Purpose/Objective:

Cervical cancer is the fourth most common cancer in women and the fourth most common cause of death from cancer in women worldwide [1]. Concurrent chemo-radiation is the current standard of treatment in cervical cancer stage IB-IVA [2]. Brachytherapy must be included as a component of the definitive radiation therapy in