ESTRO 2024 - Abstract Book

S1020

Clinical - Gynaecology

ESTRO 2024

1012

Digital Poster

Temporal changes in functional magnetic resonance imaging for cervix cancer during chemoradiotherapy

Mohammed Abdul-Latif 1 , Amani Chowdhury 1 , Hannah Tharmalingam 1 , Yatman Tsang 2 , Peter Hoskin 1,3

1 Mount Vernon Cancer Centre, Department of Clinical Oncology, Northwood, United Kingdom. 2 Princess Margaret Cancer Center, Radiation medicine programme, Toronto, Canada. 3 University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom

Purpose/Objective:

Locally advanced cervical cancer (LACC) is managed with radical chemoradiotherapy (CRT) and brachytherapy boost. Local control rates are excellent (92% at 5 years), however distant relapse continues to impact survival 1 . Risk-stratification using imaging biomarkers could be used to improve patient treatment and follow-up approach. Functional magnetic resonance imaging (fMRI) can characterise properties of locally advanced cervical cancer (LACC) including cellularity, necrosis and vascularity. Parameters derived from fMRI include apparent diffusion coefficient (ADC, water diffusion rate calculated from diffusion weighted imaging (DWI)) and the transverse relaxation rate (R2*, deoxyhaemoglobin concentration calculated from blood oxygen level dependant (BOLD) MRI). These imaging parameters have potential as predictive and prognostic biomarkers for patients receiving CRT for LACC 2 . This study aims to investigate temporal changes in fMRI parameters across CRT.

Material/Methods:

A prospective cohort study in which patients undergoing CRT (45Gy in 25 fractions with weekly cisplatin) for LACC were imaged with fMRI prior to CRT (S1), halfway (S2) and on the final day of CRT (S3). fMRI sequences performed were T2-weighted MRI (Tumour volume), DWI (ADC) and BOLD (R2*) MRI. The median (e.g. ADC med ), skewness and kurtosis, lower (e.g. ADC low ) and upper (e.g. ADC high ) quartiles for each parameter for the tumour volume were calculated, in addition to percentage changes in parameters between scans (e.g. ΔADC S1-S2 ). Correlations between parameters were calculated using Spearman's rank. Tumour volume reduction rate (TVRR) between S1, S2 and S3 and response at 3 months after treatment (Complete response (CR) or partial response (PR)) was measured.

Results:

Ten patients were included for analysis (Table 1.). The mean age was 55. Nine patients completed all three trial scans, whilst only 1 patient missed S2. At three months follow-up imaging, 8 patients achieved a CR whilst 2 a PR.

Patient

Age at treatment

Stage

Histopathology

Tumour Volume at S1 (cc)

TVRR S1S3 (%)

Response at months (Partial Vs Complete) 3

(mean

=

55.4)

EM01

38

IIIC2

SCC, HPV+

79.3

73.9

CR