Studies on radionuclide imaging and contrast ultrasound for sentinel node diagnostics in breast cancer and melanoma.

Malignant involvement of the regional lymph nodes in breast cancer, melanoma and other cancers is considered an important prognostic factor and determines the further treatment of the patient. Currently two methods are most often combined for SN detection, intra-operative blue dye injection around the tumour site and the radionuclide technique. The aims of this thesis were to evaluate the possibility of optimising the radionuclide SN procedures in patients with breast cancer and melanoma, and to examine the possibility of using contrast enhanced lympho-ultrasonography (CELUS) for SN detection. The radionuclide method was evaluated in patients with breast cancer (study I) and in melanoma patients (study II). CELUS was tested in animals (pigs and mice, study III and IV) and in melanoma patients (study IV). I. We investigated the influence on axillary SN biopsy in breast cancer patients of: a) Preoperative scintigraphy, used by some, but omitted by other centres, b) The variable activity remaining in the patient at surgery, due to differences in activity administered and to time to surgery. II. This study compared the interpretation of delayed static imaging alone with the interpretation of early dynamic and delayed static imaging in combination with SPECT/CT in the SN diagnostics in melanoma. III. This study describes the possibility of using CELUS to detect SNs in a pig model. The method worked well for SN detection in this model, in agreement with previous studies in pigs and other animals. IV. In this study we examined the possibility of using CELUS with micro bubbles to detect SN in melanoma patients.In breast cancer patients it is essential for SN detection that the injected activity is high enough for optimal SN detection, preoperative scintigraphy may be of some clinical value. A combination of the three imaging modalities works only slightly better for SN detection than a simple static gamma camera imaging in patients with melanoma, the combined procedure used as gold standard identifies 1% more patients with malignant SNs. CELUS as performed in our study worked well for SN detection in a pig model, but could not be used to detect SN in patients.