Development of a positron probe for localization and excision of brain tumours during surgery.

The survival outcome of patients suffering from gliomas is directly linked to the complete surgical resection of the tumour. To help the surgeons to delineate precisely the boundaries of the tumour, we developed an intraoperative positron probe with background noise rejection capability. The probe was designed to be directly coupled to the excision tool such that detection and removal of the radiolabelled tumours could be simultaneous. The device consists of two exchangeable detection heads composed of clear and plastic scintillating fibres. Each head is coupled to an optic fibre bundle that exports the scintillating light to a photodetection and processing electronic module placed outside the operative wound. The background rejection method is based on a real-time subtraction technique. The measured probe sensitivity for (18)F was 1.1 cps kBq(-1) ml(-1) for the small head and 3.4 cps kBq(-1) ml(-1) for the large head. The mean spatial resolution was 1.6 mm FWHM on the detector surface. The gamma-ray rejection efficiency measured by realistic brain phantom modelling of the surgical cavity was 99.4%. This phantom also demonstrated the ability of the probe to detect tumour discs as small as 5 mm in diameter (20 mg) for tumour-to-background ratios higher than 3:1 and with an acquisition time around 4 s at each scanning step. These results indicate that our detector could be a useful complement to existing techniques for the accurate excision of brain tumour tissue and more generally to improve the efficiency of radio-guided cancer surgery.

Mobile gamma cameras in breast cancer care - a review.

BACKGROUND: Currently, due to progress in detection and to extended screening, surgeons have to deal with increasing numbers of non-palpable lesions in breast cancer. These lesions can be treated by radio-guided surgery in the lumpectomy associated with sentinel lymph node (SLN) procedures. Thanks to advances in detector technology, mini gamma cameras are now available, that can perform real-time lymphoscintigraphy during surgery, or at bedside. AIM: In this article, we review the clinical literature on these dedicated cameras used in breast cancer surgery. The goal is to show how these cameras are used in breast cancer treatment and in SLN biopsy and what kind of benefits they offer. METHODS: We conducted our search on MEDLINE and EMBASE databases. We performed a comprehensive review to identify clinical studies or cases using mobile gamma cameras in breast cancer surgery. RESULTS: We collected 14 articles published between January 2000 and March 2012. We analysed the use of the mobile cameras and the obtained results. CONCLUSION: Mobile gamma cameras seem to be useful imaging tools either used pre-operatively or during surgery. They assist surgeons with accurate localization of SLNs and/or radio-labelled tumours, and in verification that all radioactive nodes have been excised.

[Place of hand-held gamma-cameras in breast cancer]. / Place des gamma-caméras portables en cancérologie mammaire.

Non-palpable breast cancers are more and more frequent. Their surgical management requires the excision of the tumor and sentinel lymph node (SLN) needing a technical preoperative organization combining preoperative identification of the tumor by wire guide and injection of a radioactive tracer for the identification of SLN. The implementation of this minimally invasive surgery is sometimes paradoxically complicated due to the presurgical organization requiring several medical teams. It is for this reason that hand-held gamma-cameras have been developed, used either preoperatively or during surgery to replace lymphoscintigraphy but also as a help to excision of the tumor after radioisotope injection. The objective of this study was to evaluate the interest of the main hand-held gamma-cameras used in breast cancer.