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Hyperthermia increases the efficiency of various chemotherapeutic drugs and is administered as an adjunct to chemotherapy for the treatment of cancer patients. The temperature-dependent effect can be strongly increased by the use of temperature-sensitive liposomes in combination with regional hyperthermia, which specifically releases the entrapped drug in the heated tumor tissue. The novel lipid 1.2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPP-GOG), which is closely related to the naturally occurring 1.2-dipalmitoyl-sn-glycero-3-phosphoglycerol, in combination with 1.2-dipalmitoyl-sn-glycero-3-phosphocholine and 1.2-distearoyl-sn-glycero-3-phosphocholine provides longcirculating temperature-sensitive liposomes with favorable properties under mildly hyperthermic conditions (41-42°C). DPPGOG facilitates temperature-triggered drug release from these liposomes (diameter, 175 nm) and leads to a substantially prolonged plasma half-life for the encapsulated drug with t 1/2 ‫؍‬ 9.6 h in hamsters and t 1/2 ‫؍‬ 5.0 h in rats. Quantitative fluorescence microscopy of amelanotic melanoma grown in the transparent dorsal skin fold chamber of hamsters demonstrated a favorable drug accumulation in heated tissue after i.v. application of these liposomes (42°C for 1 h). The mean area under the curve for tissue drug concentration was increased by more than sixfold by application of the new liposomes compared with nonliposomal drug delivery. In summary, we present a new DPPGOGbased liposomal formulation enabling long circulation time combined with fast and efficient drug release under mild hyperthermia. This adds positively to the results with lipidgrafted polyethylenglycol used thus far in temperaturesensitive liposomes and widens the possibilities for clinical applications.

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Diagnosis of avascular necrosis (AVN) of the femoral head depends on the combination of clinical symptoms and evaluation of radiographs and/or magnetic resonance imaging (MRI). To evaluate the evolution of AVN, the Ficat and the Association Research Circulation Osseous (ARCO) classification are commonly used to assess both imaging modalities. For comparison reasons, these classifications need to be reliable and reproducible to provide sufficient therapy options for the patient. Therefore, the aim of our study was to evaluate the interobserver reliability and the intraobserver reproducibility of these classifications. Patients with suspected AVN were examined using either radiographs or radiographs and MRI. The radiographs and/or MR images were reviewed initially and at 3 months by two general orthopaedic surgeons, two orthopaedic residents, and two general radiologists using the Ficat classification for radiographs and MR images as well as the ARCO classification for MR images only. In all, 38 patients (54 hips) were enrolled. There were 10 patients who presented with radiographs and 28 patients with radiographs and MR scans. Paired comparisons revealed a mean interobserver kappa reliability coefficient of 0.39 for the first and of 0.32 for the second review using the Ficat classification for radiographs, whereas for the MR images a mean of 0.39 in the first and of 0.34 in the second reading resulted. The MRI evaluation using the ARCO classification resulted in a mean interobserver reliability coefficient of 0.37 in the first and of 0.31 in the second reading. The mean kappa value for intraobserver reproducibility using the Ficat classification was 0.52 for radiographs and 0.50 for MR images, whereas a reproducibility of 0.43 resulted for the ARCO classification. This study showed poor interobserver reliability and fair intraobserver variability, diminishing any meaningful comparison of studies using the Ficat as well as the ARCO classification. Thus, the Ficat and ARCO staging systems are still not sufficient to reliably assess the status of AVN alone.Résumé Le diagnostic des nécroses vasculaires de la tête fémorale (AVN) dépend de l'analyse des signes cliniques et de l'évaluation des signes radiographiques ainsi que de l'IRM. Afin d'évaluer l'évolution de l'ostéonécrose de la hanche selon la classification de la Ficat et la classification ARCO, ces examens d'imagerie sont habituellement utilisés. Le but de notre étude est d'évaluer la fiabilité de ces différents paramètres inter et intra observateurs. Matériel et méthode : les patients suspects d'ostéonécrose de la hanche ont été examinés sur le plan radiographique et sur le plan IRM. Les radiographies et les images IRM ont été évaluées initialement trois mois après par deux chirurgiens orthopé-distes, deux résidents en orthopédie et deux radiologues en utilisant la classification du Ficat et la classification ARCO pour les images IRM. Résultats : 38 patients (54 hanches) ont été inclus dans cette étude. 10 patients n'ont bénéficié

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