University of Leicester
bjr.20190020.pdf (1.12 MB)
Download file

Assessing a small field of view hybrid gamma camera for perioperative iodine-125 seed localisation.

Download (1.12 MB)
journal contribution
posted on 2019-06-21, 14:52 authored by AH Ng, MS Alqahtani, LK Jambi, SL Bugby, JE Lees, AC Perkins
OBJECTIVES:: To examine the imaging capability of a novel small field of view hybrid γ camera (HGC) using 125I seeds prior to surgical use. METHODS:: The imaging performance of the camera system was assessed quantitatively and qualitatively at different source depths, source to collimator distances (SCD), activity levels, acquisition times and source separations, utilising bespoke phantoms. RESULTS:: The system sensitivity and spatial resolution of the HGC for 125I were 0.41 cps/MBq (at SCD 48 mm) and 1.53 ± 0.23 mm (at SCD 10 mm) respectively. The camera was able to detect the 125I seed at a SCD of 63 mm (with no scattering material in place) in images recorded within a one-minute acquisition time. The detection of the seeds beneath scattering material (simulating deep-seated tumours) was limited to depths of less than 20 mm beneath the skin surface with a SCD of 63  mm and seed activity of 2.43 MBq. Subjective assessments of the hybrid images acquired showed the capability of the HGC for localising the 125I seeds. CONCLUSION:: This preliminary ex vivo study demonstrates that the HGC is capable of detecting 125I seeds and could be a useful tool in radioactive seed localisation with the added benefit of providing hybrid optical γ images for guiding breast conserving surgery. ADVANCES IN KNOWLEDGE:: The SFOV HGC could provide high resolution fused optical-gamma images of 125I radioactive seeds indicating the potential use in intraoperative surgical procedure such as RSL.


The authors would like to thank to the Science and Technologies Facilities Council (UK) for the research funding, GE Healthcare Life Sciences (UK & US) for supplying the I-125 seeds, Simon Lawes for operating the SPECT-CT camera, Clare Jacobs for her technical advice on gamma probe and all volunteers who participated in the clinical simulation studies. The authors would also like to thank the Director General of Health Malaysia for his permission to publish this article.



British Journal of Radiology, 2019; 92: 20190020.

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy


  • VoR (Version of Record)

Published in

British Journal of Radiology


British Institute of Radiology



Acceptance date


Copyright date


Publisher version


The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.



Usage metrics

    University of Leicester Publications