Experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype for partial breast irradiation

Journal Article · Sun Jun 15 04:00:00 EDT 2008 · Medical Physics

DOI:https://doi.org/10.1118/1.2919559· OSTI ID:21120762

Ravi, Ananth; Caldwell, Curtis B; Pignol, Jean-Philippe ^[1]

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1. Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M4N 3M5 (Canada)

Previously, our team used Monte Carlo simulation to demonstrate that a gamma camera could potentially be used as an online image guidance device to visualize seeds during permanent breast seed implant procedures. This could allow for intraoperative correction if seeds have been misplaced. The objective of this study is to describe an experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype. The OGIPSI device is intended to be able to detect a seed misplacement of 5 mm or more within an imaging time of 2 min or less. The device was constructed by fitting a custom built brass collimator (16 mm height, 0.65 mm hole pitch, 0.15 mm septal thickness) on a 64 pixel linear array CZT detector (eValuator-2000, eV Products, Saxonburg, PA). Two-dimensional projection images of seed distributions were acquired by the use of a digitally controlled translation stage. Spatial resolution and noise characteristics of the detector were measured. The ability and time needed for the OGIPSI device to image the seeds and to detect cold spots was tested using an anthropomorphic breast phantom. Mimicking a real treatment plan, a total of 52 {sup 103}Pd seeds of 65.8 MBq each were placed on three different layers at appropriate depths within the phantom. The seeds were reliably detected within 30 s with a median error in localization of 1 mm. In conclusion, an OGIPSI device can potentially be used for image guidance of permanent brachytherapy applications in the breast and, possibly, other sites.

• OSTI ID: 21120762
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 6 Vol. 35; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BIOMEDICAL RADIOGRAPHY
BRACHYTHERAPY
COLLIMATORS
COMPUTERIZED SIMULATION
EVALUATION
GAMMA CAMERAS
GAMMA RADIATION
IMAGES
IRRADIATION
MAMMARY GLANDS
PALLADIUM 103
PHANTOMS
RADIATION SOURCE IMPLANTS
RADIOPHARMACEUTICALS
SPATIAL RESOLUTION