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Positron detection for the intraoperative localisation of cancer deposits.

Piert M, Burian M, Meisetschläger G, Stein HJ, Ziegler S, Nährig J, Picchio M, Buck A, Siewert JR, Schwaiger M - Eur. J. Nucl. Med. Mol. Imaging (2007)

Bottom Line: A total of 17 patients (12 receiving preoperative [(18)F]FDG PET imaging) with various histologically proven malignancies were included.In one case of a hepatic metastasis, the T/B ratio of 1.34 was below expectations, since the preoperative [(18)F]FDG PET scan was positive.The methodology holds promise for further clinical testing.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany. mpiert@umich.edu

ABSTRACT

Purpose: The study investigated the feasibility of a positron-sensitive hand-held detector system for the intraoperative localisation of tumour deposits resulting from intravenous [(18)F]FDG administration.

Methods: A total of 17 patients (12 receiving preoperative [(18)F]FDG PET imaging) with various histologically proven malignancies were included. Radioactivity from tumours and surrounding normal tissue was measured on average 3 h after administration of 36-110 MBq [(18)F]FDG and the tumour-to-background (T/B) ratio was calculated. In addition, phantom studies were performed to evaluate the spatial resolution and sensitivity of the probe.

Results: All known targeted tumour sites were identified by the positron probe. T/B ratios were generally high, with a mean T/B ratio of 6.6, allowing easy identification of most tumour sites. In one case of a hepatic metastasis, the T/B ratio of 1.34 was below expectations, since the preoperative [(18)F]FDG PET scan was positive. The probe was instrumental in the localisation of three additional tumour lesions (two lymph nodes, one anastomotic ring) that were not immediately apparent at surgery. Phantom studies revealed that [(18)F]FDG-containing gel (simulating tumour tissue), having 10 times more [(18)F]FDG than surrounding "normal" background gel, was clearly detectable in quantities as low as 15 mg. As measured in two cases, the absorbed radiation doses ranged from 2.5 to 8.6 microSv/h for the surgical team to 0.8 microSv/h for the aesthetician.

Conclusion: [(18)F]FDG-accumulating tumour tissues can be localised with positron probes intraoperatively with a low radiation burden to the patient and medical personnel. The methodology holds promise for further clinical testing.

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Related in: MedlinePlus

Positron (a) and collimated high-energy gamma (b) probes manufactured by Silicon Instruments (Berlin, Germany)
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Fig1: Positron (a) and collimated high-energy gamma (b) probes manufactured by Silicon Instruments (Berlin, Germany)

Mentions: The detector unit of the intraoperative beta-probe system used in this study consists of a silicon detector incorporated into a single compact unit. The detector’s design has been optimised for a high beta particle sensitivity and low absorption of detector-penetrating photons. The shaft of the probe has a diameter of 11 mm while the tip of the detector has an outer diameter of 16 mm with an active circular detector area of 20 mm2 at the tip of the probe. The front face of the tip is covered with an extremely thin layer of light-impenetrable foil to ensure insensitivity to light and electromagnetic shielding. Electrical connections from the detectors to the electronics boards located in the probe handle are routed through a stainless steel tube connecting the probe tip and handle. The probe weighs 65 g and is easily handled by the surgeon (Fig. 1).Fig. 1


Positron detection for the intraoperative localisation of cancer deposits.

Piert M, Burian M, Meisetschläger G, Stein HJ, Ziegler S, Nährig J, Picchio M, Buck A, Siewert JR, Schwaiger M - Eur. J. Nucl. Med. Mol. Imaging (2007)

Positron (a) and collimated high-energy gamma (b) probes manufactured by Silicon Instruments (Berlin, Germany)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2562440&req=5

Fig1: Positron (a) and collimated high-energy gamma (b) probes manufactured by Silicon Instruments (Berlin, Germany)
Mentions: The detector unit of the intraoperative beta-probe system used in this study consists of a silicon detector incorporated into a single compact unit. The detector’s design has been optimised for a high beta particle sensitivity and low absorption of detector-penetrating photons. The shaft of the probe has a diameter of 11 mm while the tip of the detector has an outer diameter of 16 mm with an active circular detector area of 20 mm2 at the tip of the probe. The front face of the tip is covered with an extremely thin layer of light-impenetrable foil to ensure insensitivity to light and electromagnetic shielding. Electrical connections from the detectors to the electronics boards located in the probe handle are routed through a stainless steel tube connecting the probe tip and handle. The probe weighs 65 g and is easily handled by the surgeon (Fig. 1).Fig. 1

Bottom Line: A total of 17 patients (12 receiving preoperative [(18)F]FDG PET imaging) with various histologically proven malignancies were included.In one case of a hepatic metastasis, the T/B ratio of 1.34 was below expectations, since the preoperative [(18)F]FDG PET scan was positive.The methodology holds promise for further clinical testing.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany. mpiert@umich.edu

ABSTRACT

Purpose: The study investigated the feasibility of a positron-sensitive hand-held detector system for the intraoperative localisation of tumour deposits resulting from intravenous [(18)F]FDG administration.

Methods: A total of 17 patients (12 receiving preoperative [(18)F]FDG PET imaging) with various histologically proven malignancies were included. Radioactivity from tumours and surrounding normal tissue was measured on average 3 h after administration of 36-110 MBq [(18)F]FDG and the tumour-to-background (T/B) ratio was calculated. In addition, phantom studies were performed to evaluate the spatial resolution and sensitivity of the probe.

Results: All known targeted tumour sites were identified by the positron probe. T/B ratios were generally high, with a mean T/B ratio of 6.6, allowing easy identification of most tumour sites. In one case of a hepatic metastasis, the T/B ratio of 1.34 was below expectations, since the preoperative [(18)F]FDG PET scan was positive. The probe was instrumental in the localisation of three additional tumour lesions (two lymph nodes, one anastomotic ring) that were not immediately apparent at surgery. Phantom studies revealed that [(18)F]FDG-containing gel (simulating tumour tissue), having 10 times more [(18)F]FDG than surrounding "normal" background gel, was clearly detectable in quantities as low as 15 mg. As measured in two cases, the absorbed radiation doses ranged from 2.5 to 8.6 microSv/h for the surgical team to 0.8 microSv/h for the aesthetician.

Conclusion: [(18)F]FDG-accumulating tumour tissues can be localised with positron probes intraoperatively with a low radiation burden to the patient and medical personnel. The methodology holds promise for further clinical testing.

Show MeSH
Related in: MedlinePlus