Quantitative investigation of a novel small field of view hybrid gamma camera (HGC) capability for sentinel lymph node detection

Journal Article

Alqahtani, Mohammed . 2016

• رابط المنشور على الويب: Quantitative investigation of a novel small field of view hybrid gamma camera (HGC) capability for sentinel lymph node detection
• المجلة \ الصحيفة: British Journal of Radiology
• رقم العدد: 0
• رقم الإصدار السنوي: 0
• الصفحات: 20160435

مستخلص المنشور

Objectives:

The Hybrid Gamma Camera (HGC) has been developed to enhance the localisation of radiopharmaceutical uptake in targeted tissues during surgical procedures such as sentinel lymph node (SLN) biopsy. To assess the capability of the HGC, a lymph-node-contrast (LNC) phantom was constructed to simulate medical scenarios of varying radioactivity concentrations and SLN size.

Methods:

The phantom was constructed using two clear acrylic glass plates. The SLNs were simulated by circular wells of diameters ranging from 10mm to 2.5mm (16 wells in total) in one plate. The second plate contains four larger rectangular wells to simulate tissue background activity surrounding the SLNs. The activity used to simulate each SLN ranged between 4MBq and 0.025MBq. The activity concentration ratio between the background and the activity injected in the SLNs was 1:10. The LNC phantom was placed at different depths of scattering material ranging between 5mm and 40mm.The collimator to source distance was 120mm. Image acquisition times ranged from 60s to 240s.

Results:

Contrast to Noise Ratio (CNR) analysis and Full-Width-at-Half-Maximum (FWHM) measurements of the simulated SLNs were carried out for the images obtained. Over the range of activities used the HGC detected between 87.5% and 100% of the SLNs through 20mm of scattering material, and 75% to 93.75% of the SLNs through 40mm of scattering material. The Full-Width-at-Half-Maximum (FWHM) width of the detected SLNs ranged between 11.93mm and 14.70mm.

Conclusion:

The HGC is capable of detecting low accumulation of activity in small SLNs indicating its usefulness as an intraoperative imaging system during surgical SLN procedures.

Advances in knowledge:

This study investigates the capability of a novel small-field-of-view HGC to detect low activity uptake in small SLNs. The phantom and procedure described are inexpensive and could be easily replicated and applied to any SFOV camera, to provide a comparison between systems with clinically relevant results.