Image guided brachytherapy in cervix cancer: Optimising technique, applicators, and treatment planning

2020.11.05 | Graduate School of Health

Friday 20 November at 15:00, Monica Serban defends her PhD dissertation entitled "Image guided brachytherapy in cervix cancer: Optimising technique, applicators, and treatment planning".

The standard treatment for locally advanced cervical cancer (LACC) is a combination of external beam radiotherapy (EBRT), brachytherapy (BT), and concomitant chemotherapy. BT represents an important component of the treatment, as it accounts for about half of the total peripheral dose to the tumour. The EMBRACE I study aimed to benchmark magnetic resonance image-guided adaptive BT (MR IGABT) in LACC as a prospective observational multicentre study, with 1416 patients enrolled. The goal of this PhD was to investigate the improvements achieved in the LACC treatment by MRIGABT along with intracavitary/interstitial (IC/IS) techniques and individualized dose optimization approaches specific to each patient anatomy/tumour. Four projects were conducted to investigate: (1) the overall treated volumes by clinically relevant dose levels with IGABT and compare to the standard loading (SDL-IC) volumes; (2) the influence of applicator and technique type on target and organs at risk (OARs) doses; (3) the dosimetric performance of combined IC/IS BT including parallel/oblique P/O-needles in patients with extensive parametrial/vaginal disease; (4) a methodology for generating vaginal dose-surface maps (DSMs) and new dose-spatial descriptors for prediction of vaginal morbidity. Increased target doses and dose conformity were achieved with MR-IGABT. Patients treated with tandem&ring had a more favorable therapeutic ratio and conformal dose distribution than patients treated with tandem&ovoids applicators. For both applicators, the addition of needles considerably increased target and decreased OAR doses. The use of IC/IS technique and P/O-needles ensured excellent target dose and OARs D2cm3. Intrauterine/vaginal loadings were reduced compared to SDL-BT and shifted into needles, by gentle loading in the majority of dwell positions. DSMs showed that spatial information and dose-surface metrics seem to be superior to dose-point, as current clinical practice for vaginal dose reporting. 

The summary is written by the PhD student.    

The defence is public and takes place online via Zoom. Please read the attached press release for more information.

Contact:

PhD student Monica Serban

Mail: monica.serban@oncology.au.dk

Phone: (+1) 5149935256

Read full press release