BioXmark® is made available for all participants in the PROTECT esophagus cancer trial

1 April 2022

  • PROTECT is a multicenter European clinical study comparing proton and photon radiation therapy as a part of neoadjuvant chemoradiation for patients with resectable esophageal cancer
  • The use of fiducial markers is an option in the study protocol, and BioXmark® is a liquid fiducial marker that has demonstrated good performance, safety and technical feasibility in esophageal cancer treatment

The PROTECT trial is an open-label, non-blinded, international multicenter, randomized clinical phase III study for patients with operable esophageal cancer or esophagogastric cancer. In the study, patients will be randomized to receive either neoadjuvant chemoradiotherapy (standard of care) or neoadjuvant chemo-proton-therapy (intervention). The overall objective of the trial is to test the hypothesis that proton therapy enabled radiation dose reductions to sensitive, normal tissues will result in lower rates of treatment-related pulmonary complications in esophageal cancer compared to standard photon therapy.


The study is projected to run over 6 years, from 2021 to 2027, involving more than 30 clinical sites in 9 countries and enrolling close to 400 patients. The primary study endpoint is the incidence of pulmonary complications during and following neoadjuvant chemoradiotherapy or neoadjuvant chemo-proton-therapy – and surgery. The proportion of patients with pulmonary complications will be compared between the two arms.


BioXmark® is a liquid fiducial marker that has demonstrated good performance, safety and technical feasibility across a number of organs including the esophagus (1,2). The liquid marker stands out also, having shown low dose perturbation for compatibility with both photon and proton therapy. BioXmark® is developed and marketed in Europe by Nanovi to radiographically mark soft tissue for enhanced target visibility on imaging.


Nanovi has agreed to make BioXmark® available, free of charge, for all participants in the multicenter PROTECT esophagus cancer trial. The use of fiducial markers is an option under the trial protocol to support the accurate delivery of radiation therapy.


For participants in the PROTECT trial:

A one-page introduction to BioXmark® and to the use of the liquid marker in esophageal cancer has been included with the study protocol. For further information on the product, including scientific publications, white papers, introduction video and user guidance, please contact Nanovi.


Click here to download a PDF version of the news release.



  1. Machiels M, Voncken FEM, Jin P, Dieren JM van, Bartels-Rutten A, Alderliesten T, et al. A Novel Liquid Fiducial Marker in Esophageal Cancer Image Guided Radiation Therapy: Technical Feasibility and Visibility on Imaging. Practical Radiation Oncology. 2019 Nov 1;9(6):e506–15.
  2. de Blanck SR, Scherman-Rydhög J, Siemsen M, Christensen M, Baeksgaard L, Irming Jølck R, et al. Feasibility of a novel liquid fiducial marker for use in image guided radiotherapy of oesophageal cancer. Br J Radiol. 2018 Dec;91(1092):20180236.