An original approach in the diagnosis of early breast cancer: use of the same radiopharmaceutical for both non-palpable lesions and sentinel node localisation

A modern approach to the surgical treatment of early breast carcinoma requi res intraoperative localisation of non-palpable lesions and assessment of t he lymph node status. Localisation of breast lesions can be achieved by int ratumoural injection of a small amount of radiotracer and intraoperative us e of a gamma probe (i.e. radioguided occult lesion localisation, or ROLL). Assessment of the lymph node status is possible by means of the sentinel no de approach. To date, two different radiopharmaceuticals have been used for localisation of tumour and sentinel node. We now propose the use of a sing le nanocolloidal tracer (Nanocoll, with a particle size of less than 80 nm) which is labelled with technetium-99m for simultaneous performance of ROLL and sentinel node identification. The aim of this study was to evaluate th e feasibility of this approach. which should be easier and more practical t han the dual-tracer injection method. We have employed this new technique i n 73 patients with non-palpable, cytologically diagnosed breast cancer and non-palpable axillary lymph nodes. In all patients the radiocolloid, in a t otal volume of 0.3-0.4 cc, was injected under sonographic or stereotactic g uidance. Half of the dose was injected intratumourally and half superficial ly, but very close to the tumour. Because of the slow lymphatic flow in the breast, Nanocoll must be injected some time before surgery in order to ena ble adequate migration to the axilla. We injected colloid in the afternoon before surgery (16-23 h before the start of the operation, with an average interval of 18 h). An average dose of 130 MBq (range 110-150) was injected in order to have about 10 MBq of radioactivity when surgery commenced. Lymp hoscintigraphy was performed after 15-19 h. with an average interval of 17 h. The procedure was always successful in permitting the localisation of oc cult breast lesions. Lesions were always localised at the first attempt, an d were always contained within the surgical margins. Histological examinati on revealed all 73 resected lesions to be malignant: there were 64 cases of infiltrating carcinoma and nine of intraductal carcinoma. All breast lesio ns were therefore confirmed to be early breast cancer. We achieved sentinel node localisation in 71 out of 73, either at scintigraphy or with the intr aoperative probe; in two patients, radiopharmaceutical migration was absent . Lymphoscintigraphy showed only axillary drainage in 52 cases, only intern al mammary chain (IMC) drainage in nine cases, and combined axillary and IM C drainage in eight cases. In two cases, lymphoscintigraphy suggested the s entinel node was located inside the same breast (intramammary lymph node). All the visualised sentinel nodes were biopsied except for four that were l ocalised in the IMC. Histological examination of the nodes showed metastase s in 20 cases: in 15 cases there were micrometastases, and in five, macrome tastases. In conclusion, this study has demonstrated the feasibility of the proposed procedure. Simultaneous performance of ROLL and sentinel node loc alisation using a single tracer represents a useful and practicable choice in the management of early breast cancer.