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MSc Defense: Characterization of a Single Pixel Beta Detector for Guidance in Breast-conserving Surgery

Wednesday, June 20, 2018 - 12:00
KHS 335

Presenter: Amritpal Singh
Supervisors: Dr. Ananth Ravi, Dr.Carl Kumaradas

Breast-conserving surgery (BCS) is a challenging surgical procedure due to the lack of intra-operative image guidance available to surgeons. One potential method of intra-operative guidance would be radio-guided surgery with a radiopharmaceutical emitting beta particles. In this thesis, a single pixel beta sensitive detector was constructed and characterized for intra-operative guidance during BCS. The thickness of the scintillation element of the detector was optimized to obtain a superior beta to gamma detection ratio. A computer model of the detector response was derived from an empirically measured, two-dimensional (2D) detector response. An in silico study evaluated whether the novel single pixel beta detector could detect sub-millimetre deposits of cancer at the cut edge of the surgically excised breast cancerous tissue, with a sensitivity of 95%.

The thickness of 0.5 mm of a CaF2(Eu) scintillator was found to be superior for beta to gamma detection ratio. Additionally, according to an in silico study it is expected that with an imaging time of 30 seconds, the tumour-to-background ratio of 5 or higher, and a normal breast tissue activity of 1.69 kBq/ml, sub-millimetre tumour detection is feasible.

Results of this thesis demonstrate that the radio-guided BCS, with a CaF2(Eu) scintillation beta particle detector, has the potential to intra-operatively access the tumour margin involvement, which could help the surgeon in surgical decision making.