ÖGUM-Preis 2011 verliehen

Ein feierlicher Punkt auf der Generalversammlung, die im Rahmen des WFUMB 2011 Kongresses in Wien stattfand, war die Verleihung des ÖGUM-Preises an Herrn Dr. Loizides, Innsbruck (das Foto zeigt den Preisträger (rechts) mit dem ÖGUM-Präsidenten bei der Urkundenübergabe).

Univ.-Prof. Dr. Horst Steiner und Dr. Loizides.

Herr Dr. Loizides (Jhrg. 1977) hat an der Med. Univ. Innsbruck von 1997–2006 Human- medizin studiert und 2006 über "Kontrastverstärkte Sonografie bei Epicondylitis lateralis humeri" dissertiert. Seitdem geht er seiner Facharztausbildung für Radiologie am Department für Radiologie der Med. Univ. Innsbruck nach. Die prämierte Arbeit entstand in dieser Zeit mit den Ko-Autoren S. Peer, M. Plaikner, T. Djurdjevic und H. Gruber. Der Abstract wird hier gekürzt wiedergegeben:

"Perfusion Pattern of Musculoskeletal masses using contrast enhanced ultrasound: a helpful tool for the characterization?"

Introduction

The foremost aim in the work-up of musculoskeletal tumors is to differentiate benign from malignant variants. Despite substantial progress in diagnostic imaging, however, a correct diagnosis in terms of tumor subtype and definition of malignant potential is often not achieved based on imaging alone.

An important microanatomical feature, which distinguishes malignant tumors from their benign counterparts, is tumor vascularity. As is known from imaging of the liver, 2nd generation ultrasound contrast agents have the potential to identify even smallest intra-tumoral vessels. While little is known about the application of CEUS for characterization of musculoskeletal masses, the definition of different perfusion patterns might alter imaging based decisions in musculoskeletal tumor-management. Malignant neoplasms typically proliferate more rapidly, which results in a decreased blood supply in the tumor center and subsequent tumor necrosis. Based on this pathophysiological consideration a 4-type CEUS pattern was established according to the findings in 54 patients with histologically validated musculoskeletal masses who underwent grey-scale-US, CEUS and subsequent ultrasound guided biopsy.

Material and Methods

54 patients (27 males, 27 females; mean age: 53 years) underwent a standardized US-assessment algorithm including high resolution grey-scale US and CEUS followed by subsequent ultrasound-guided biopsy. All sonographies were performed with a 12–5 MHz or a 9–3 MHz broadband linear transducer with CEUS capability on a Philips iU22® (Philips, Bothell, Washington, USA). The quantitative perfusion analysis software integrated on the Philips iU22® (QLAB™) was used for time intensity curve (TIC) analysis of tumor enhancement: the maximum enhancement image ("dBMax-image") was subsequently used for qualitative assessment. The sound intensity at the ascending slope of the curve (dBMin), the overall maximum sound intensity (dBMax) and the time to peak (TTP) were calculated. A blinded assessment of the "dBMax-image" was secondarily done by two specialized musculoskeletal radiologists. Each mass was assigned to one of four preliminarily defined perfusion patterns (P1–P4):

• P1: Non-enhancing mass or only rimenhancement of the surrounding pseudo-capsule.

• P2: Peripherally enhancing mass with non-enhancing central area.

• P3: Diffusely enhancing mass with scattered non-enhancing areas and/or enhancement bridges.

• P4: Completely enhancing mass.

Results

The single event probability for malignancy was 0 % for P1 perfusion pattern, 60 % for P2 perfusion pattern, 80 % for P3 perfusion pattern and 0 % for P4 perfusion pattern.

The overall prevalence of malignancy in our patients was 50 % (95 %-CI: 36 %–64 %): P3-pattern showed a sensitivity of 89 % and a specificity of 78 %. If musculoskeletal masses presented either a P2 or P3 pattern the combined sensitivity rose to 100 % at a specificity of 70 %. The feature of mass localization under the subcutaneous fascia combined with P3 pattern resulted in a sensitivity of 85 % at a specificity of 89 %; the combination of localization under the subcutaneous fascia with either a P2 or P3 pattern resulted in a sensitivity of 96 % at a specificity of 82 %.

Combination of maximum size with either P2 or P3 perfusion pattern led to a sensitivity of up to 85 % and a specificity of 81 % for masses larger than 3.3 cm; other feature combinations led to high specificities however at useless sensitivities.

"Three-feature combinations" of localization, size and perfusion pattern resulted in sensitivities up to 89 % and specificities up to 93 % with a PPV and NPV 86 % and 88 % respectively.

Conclusion

The proposed diagnostic algorithm based on a combination of perfusion pattern analysis and morphological tumor criteria results in a high combined sensitivity and specificity for the differential diagnosis of benign and malignant soft tissue masses comparable to the diagnostic range which is achieved with MRI. This may streamline the management of patients with musculoskeletal masses and potentially avoid a substantial amount of tumor biopsies – the latter however must be confirmed in a larger, controlled trial.

Wir gratulieren dem Preisträger und dem Team sehr herzlich!