MONA LISA

Background

The standard treatment for locally advanced cervical cancer (LACC) is external beam radiotherapy (EBRT) combined with chemotherapy, followed by brachytherapy. While this approach achieves high local control, patients often experience significant side effects, and nodal and distant recurrences remain a concern.

Online adaptive radiotherapy

At Erasmus MC, online adaptive radiotherapy has been implemented to improve treatment precision for several tumor sites. Online adaptive radiotherapy enables real-time adaptation of the treatment plan to the patient’s daily anatomy. Using high-quality cone-beam CT (CBCT) scans, the target volumes and organs at risk are visualized, and a new version of the treatment plan is calculated for each treatment fraction. This can lead to improved tumor coverage and a lower dose to the organs at risk.

Aim of our project

The MONA LISA study aims to improve clinical outcomes and reduce treatment-related toxicity in patients with LACC treated with daily online adaptive external radiotherapy. Study objectives include evaluating the possibility of reducing planning target volume (PTV) margins, assessing intra- and interfraction motion and response of the tumor and pathological lymph nodes, and analyzing toxicity. Furthermore, the possibility of iso-toxic dose escalation to the pathological lymph nodes will be assessed in a later stage.

Reducing safety margins

By using an online adaptive approach the treatment plan is adapted to the position of the tumor targets at the time of irradiation, eliminating the need for large safety margins. The primary aim of the MONA LISA study is to assess whether the planning target volume (PTV) margins can be reduced safely, without compromising target coverage. It is estimated that a reduction of the PTV margins can lead to a lower dose to the organs at risk, and potentially reduce treatment-related toxicities.

Monitoring inter- and intrafraction movement

Daily pre- and post-treatment CBCT scans enable detailed assessment of the motion and response of the tumor, uterus and lymph nodes during and between treatment fractions. This can provide insight into anatomical variability throughout the course of treatment, helping to determine adequate target margins and improve the accuracy of dose delivery.

Evaluating toxicity and quality of life

Physician-reported toxicity scores are documented using different CTCAE v5.0 items, and patient-reported symptoms and quality of life are collected using validated EORTC questionnaires (C30 and CX24). This data is collected at different timepoints during and after the radiotherapy treatment, to be able to evaluate acute and late treatment-related toxicities. Ultimately, this data will allow to demonstrate the impact of treatment improvements on the patient’s quality of life.

Iso-toxic dose escalation

When it is possible to safely reduce the PTV margins, there may be a possibility to increase the dose to the pathological lymph nodes without increasing toxicity. The final aim of this study is to assess the possibility of an iso-toxic dose-escalation in bulky pathological lymph nodes for patients with node-positive LACC, to enhance tumor control while maintaining acceptable toxicity levels.

- Henrike Westerveld - Principal Investigator (medical doctor)
- Jérémy Schiphof-Godart - Principal Investigator (clinical physicist)
- Harriëtte Dankers – Project coordinator & PhD candidate
- Mischa Hoogeman
- Remi Nout
- Maarten Dirkx
- Judith Sluijter
- Manon de Pee
- Claudia Verheijen