PhD ceremony Ms. P.A. Erba: Imaging cardio-vascular infection

PhD ceremony: Ms. P.A. Erba

Dissertation: Imaging cardio-vascular infection

Promotor(s): prof. A. Signore, prof. G. Mariani, prof. R.A.J.O. Dierckx

Faculty: Medical Sciences

The introduction of a hybrid system for combining functional and anatomical imaging gave the opportunity to expand our clinical experience with ^99mTc-HMPAO radio labelled leukocytes scintigraphy in the field of infectious disease, by applying these technologies to new challenging clinical setting as in the presence of cardiovascular system infections. We applied ^99mTc-HMPAO SPECT/CT hybrid imaging to patients with infectious endocarditis (IE), cardiovascular implanted electronic device (CIED) infections, or late and low-grade late vascular graft infections (VPI). In addition, we tried to establish how the use of standardized imaging acquisition protocols and new, bacterial specific, radiopharmaceuticals may improve the scintigraphic accuracy. Our results demonstrate that the use of ^99mTc-HMPAO-WBC scintigraphy is beneficial in patients with a high clinical probability of IE, CIED and VPI infections with the following main clinical indications: i) the confirmation of diagnosis in doubtful circumstances, ii) defining the extent of device involvement, and iii) detecting associated complications and septic embolisms, thus impacting on treatment strategy . SPECT/CT combined technology is preferred to visualize infection by ^99mTc-HMPAO-WBCs . Our findings support the use of ^99m Tc-HMPAO-WBC scintigraphy also to monitor the response to antimicrobial treatment . From a methodological perspective, we demonstrated that the most accurate imaging acquisition protocol for ^99mTc-HMPAO-WBC scintigraphy is scanning at 3-4h and at 20-24h after ^99mTc-HMPAO-WBCs injection, corrected for isotope decay. Semi-quantitative analysis might be deserved to doubtful cases. In view of the research on new radiopharmaceuticals to image infectious processes, our results suggest ⁶⁸Ga-DOTA-Biotin as a suitable candidate for further clinical development.