A proof-of-concept study to evaluate 99mTechnetium radiolabelled Fucoidan as diagnostic modality for thrombosis

The development of an innovative imaging agent capable of non-invasively
detecting fresh thrombus formation would greatly aid in the diagnosis and risk
stratification of a large spectrum of different diseases, amongst which are
recurrent deep vein thrombosis, pulmonary embolism, myocardial infarction and
stroke. Furthermore, as our imaging target P-selectin is upregulated in
activated endothelium, this imaging agent will likely be able to identify
vulnerable plaques. Additionally, this imaging technique is likely to be able
to distinguish fresh from old thrombus, thereby allowing us to distinguish
between a recurrence of deep vein thrombosis and post-thrombotic syndrome.
Hereby we can prevent unnecessary lifelong anticoagulant treatment.

To determine the uptake of 99mTc-Fucoidan in a fresh thrombus of patients with
acute deep vein thrombosis (DVT).

A single-center, interventional, open, non-randomized, diagnostic assessment
(phase IIa) of a new imaging agent in 12 patients with acute DVT.

The results of this study contribute to the development of a novel imaging
biomarker in a very large spectrum of thrombotic diseases. For cardiovascular
diseases, this may allow for better identification of high-risk patients and
might be more specific than conventional diagnostic methods in patients with a
cardiovascular event. In the case of DVT, this imaging technique could
potentially differentiate between acute and chronic events, thereby preventing
unnecessary treatment. As the current study is a phase IIa study, subjects
receive no direct or immediate benefits. There are no direct toxic effects
associated with the administration of 99mTc-Fucoidan, except for the limited
risks inherent to radiation exposure.

Note that all included subjects have experienced a first episode of DVT, and 1
out of 5 patients will experience a recurrence in the first 5 years. In case
this tracer (99mTc-Fucoidan) effectively detects fresh thrombus, the patients
themselves may benefit in the future from the correct diagnosis of recurrent
DVT versus post-thrombotic syndrome, possibly preventing unnecessary lifelong
treatment. Therefore, the subjects fall into risk category IIb, according to
the *Human exposure to ionising radiation for clinical and research purposes*
guidelines of the Netherlands Commission on Radiation Dosimetry (CCMO website).