Today, it is estimated that around one person out of three will face cancer over the course of his or her life, and this number is expected to rise significantly in future years. Comprised in the cure of approximately 50% of all cancer patients, radiation therapy is a treatment modality that has been proven effective in reducing cancer-induced mortality. The malignant tumour is exposed to a beam of high energy photons, typically delivered by a linear accelerator. Radiation can cause DNA damage and therefore induce cell death. The success of the treatment relies on the ability to achieve high tumour conformity, by maximising the dose delivered to the tumour while keeping the healthy tissue exposure as low as possible. To this aim, increasingly complex treatment plans and delivery methods are employed, leading to highly modulated spatiotemporal dose profiles. Consequently, inaccuracies in treatment delivery or patient positioning can have dreadful consequences, and appropriate treatment verification strategies effectively measuring the actual radiation dose imparted to the tumour are actively sought. Despite this unmistakable need, current dosimetry technology is lagging behind on radiotherapy planning and delivery evolutions, hereby inhibiting the full potential of radiotherapy.

Amphora aims to develop a non-invasive in-situ dosimetry system for radiation therapy with the potential of on-line dose assessment by casting ultrasound contrast agents (UCAs) into dose sensing theranostic devices. UCAs will be upgraded to injectable dose-sensitive and targeted devices that gather in tumour tissue and translate imparted radiation dosage into a modulation of their acoustic response upon ultrasound interrogation.

Our main objectives are the following:

• The design, development and optimisation of targeted radiation-sensitive UCAs accumulating in (and around) the tumour and changing their acoustic properties as function of radiation dose
• The design and implementation of dose distribution read-out technology using ultrasound imaging through quantification of radiation induced changes of UCAs that are (heterogeneously) distributed in (and around) tumour tissue
• The evaluation and validation of the different aspects of the new dosimeter concept both in vitro and in vivo using small animal models