%0 Journal Article
%T Feasibility Evaluation of Radioimmunoguided Surgery of Breast Cancer
%A Ananth Ravi
%A Raymond M. Reilly
%A Claire M. B. Holloway
%A Curtis B. Caldwell
%J International Journal of Molecular Imaging
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/545034
%X Breast-conserving surgery involves completely excising the tumour while limiting the amount of normal tissue removed, which is technically challenging to achieve, especially given the limited intraoperative guidance available to the surgeon. This study evaluates the feasibility of radioimmunoguided surgery (RIGS) to guide the detection and delineation of tumours intraoperatively. The 3D point-response function of a commercial gamma-ray-detecting probe (GDP) was determined as a function of radionuclide (131I, 111In, 99mTc), energy-window threshold, and collimator length (0.0¨C3.0-cm). This function was used to calculate the minimum detectable tumour volumes (MDTVs) and the minimum tumour-to-background activity concentration ratio (T:B) for effective delineation of a breast tumour model. The GDP had larger MDTVs and a higher minimum required T:B for tumour delineation with 131I than with 111In or 99mTc. It was shown that for 111In there was a benefit to using a collimator length of 0.5-cm. For the model used, the minimum required T:B required for effective tumour delineation was 5.2 ¡À 0.4. RIGS has the potential to significantly improve the accuracy of breast-conserving surgery; however, before these benefits can be realized, novel radiopharmaceuticals need to be developed that have a higher specificity for cancerous tissue in vivo than what is currently available. 1. Introduction In North America, over 60% of breast cancer patients receive breast-conserving surgery [1]. The primary goal of this operative procedure is the complete excision of the cancerous lesion, with a margin of grossly normal tissue. The purpose of this margin is to reduce the probability that microscopic disease remains. A secondary, conflicting goal is to limit the volume of normal tissue that is excised, thereby reducing patient morbidity and improving cosmesis. Achieving these goals is technically challenging, and incomplete excision occurs in 15¨C40% of breast-conserving operations, with pathologic evaluation revealing cancerous cells at the cut edge of the excised volume [2, 3]. Studies by Park et al. [4] and Peterson et al. [5] have independently shown that tumours with diameters greater than 2£¿cm have a higher likelihood of involved margins than smaller tumours. This may be attributed to the presence of nonpalpable disease at the boundaries of these tumours. This largely intra-ductal disease is difficult to detect using currently available guidance techniques that rely on anatomical differences between normal tissue and tumour [2, 6]. There is currently only limited
%U http://www.hindawi.com/journals/ijmi/2012/545034/