The transfusion of allogenic, in vitro expanded natural killer cells (NKC) is a novel therapy option in oncology. To date, however, the biodistribution and kinetics of allogenic NKC have not been investigated. Therefore, in this study three patients with renal cell carcinoma received 3-7 x 10(8) NKC labelled with indium-111 oxine with a tenfold excess of unlabelled cells during NKC therapy. Whole-body scintigrams were obtained (0.5-144 h) in the anterior and posterior views. Scintigrams were analysed using a region of interest technique, and single-photon emission tomography (SPET) studies of the abdomen were performed. Results were compared to those obtained with polymerase chain reaction (PCR) of the peripheral blood (determination of foreign DNA, nested PCR, limit of detection 0.01%). Shortly after transfusion of NKC, more than 50% of the activity was accumulated in the lungs. We observed redistribution effects from lungs to liver, spleen and bone marrow. No significant loss of activity could be detected. In two of four large metastases, tracer accumulation could be proven by SPET. As confirmed by scintigrams and PCR, the fraction of circulating transfused cells was low at all times. Long-term activity retention might be caused either by survival of the allogenic cells, as confirmed by PCR (up to 3 days p.i.), or by phagocytosis of labelled cellular fragments. However, PCR data and uptake in metastases indicated long survival of a portion of allogenic NKC. Such long survival and low retention of the cells in the lung are requirements for an effective immunotherapeutic approach.

No abstract

No abstract

This study compares the performance and image quality of two gamma camera based PET systems of the first and latest generation. We investigated two dual head coincidence gamma cameras (PRISM 2000XP and AXIS, manufactured in 1997 and 2001 by Picker/Philips) predominantly in accordance with the NEMA NU2-1994 and NU2-2001 protocols. All performance parameters except for spatial resolution and image quality were determined after measuring a standard cylinder over several half-life periods. Scatter and random fractions were evaluated with the sinogram technique. In order to determine spatial resolution and image quality we used phantoms as described in the NEMA NU2-2001 protocol. The efficiency of the new system was found to be increased. True count rate at activity levels used in clinical conditions is improved and scatter fraction is decreased substantially. Accordingly, improved spatial resolution and image quality were observed with the new system. Altogether, the AXIS represents a further approach to the performance of dedicated positron emission tomographs.

Zusammenfassung Ziel: Patienten exhalieren 1-131 nach Radioiodtherapie. Ziel der vorliegenden Studie ist die Bestimmung der von Angehörigen von Radio- iodtherapiepatienten nach Entlassung aus der Therapiestation inkorporierten Aktivität und der daraus resultierenden Schilddrüsendosis. Methoden: Bei 31 Angehörigen von Radioiodtherapiepatienten wurde die Schilddrüsenaktivität mittels der Schilddrüsensonde eines Ganzkörperzählers gemessen und daraus Dosiswerte bestimmt. Ergebnisse: Bei 11 der 31 Messungen wurde keine Aktivität oberhalb der Nachweisgrenze von 13 Bq festgestellt. Im Mittel wurde bei den restlichen Personen 104 Bq gemessen, entsprechend einer daraus resultierenden mittleren Schilddrüsendosis von 0,2 mSv (Maximalwert: 2 mSv). Schlußfolgerung: Die Zufuhr von 1-131 bei Angehörigen von Radioiodtherapiepatienten nach deren Entlassung ist gering und führte in keinem Fall zu einer effektiven Dosis von mehr als 1 mSv.