Radiation protection of the workers in radio guided surgery of breast cancer

The methods of nuclear medicine are increasingly used to complement standard diagnostic examinations (echography and mammography) with the aim of facilitating conservative surgery in breast cancer. Notable among these are the radio guided detection of the sentinel lymph node (SN) and the radio guided localization of occult lesions (ROLL). The SN technique is used in small-size (T1-T) breast carcinoma and involves the identification, removal and immediate histological examination of the first lymph node draining the area containing the tumour; if histological examination is negative the total armpit dissection is not necessary. The purpose of ROLL is to localize non-palpable breast lesions and to facilitate their removal during surgery, replacing the established hook wire method. These two new methods are based on the use of particles that, because of their size, are either trapped at the injection site (ROLL), or move from the point of injection into the lymphatic ducts, to be trapped into the SN. Specifically, particles of colloidal human serum albumin are labelled with low activities of ''99mTc and are inoculated into the breast lesion in the case of ROLL, or close to it in the case of SN biopsy. Subsequently, a hand-held γ-ray detecting probe is used to locate the lesion of the SN as a hot spot and guide its surgical removal. The aim of this work is to present dosimetric evaluations of patients and hospital personnel involved in these techniques, and to determine whether specific radiation protection procedures are required. (Author)