Evaluation of occult lymph node metastases by means of 99mTc-MIBI scintigraphy and sentinel node biopsy with RT-PCR multi-marker assay in early-stage melanoma patients

Early diagnosis of regional lymph node metastasis is a key step in the management of melanoma patients. This enables the identification of those patients who are candidates for adjuvant therapy and early therapeutic lymph node dissection. PET using FDG, has been shown to be effective in detecting recurrent melanoma lesions. However, this technique has no proved to offer any significant advantage in diagnostic sensitivity for pre-treatment nodal staging. Lymphoscintigraphy along with intraoperative probe detection of the sentinel node (SN) has become widely accepted for regional lymph node staging. Serial sectioning and immuno-histochemistry (IHC) have been shown to improve the detection of occult melanoma cells, compared with conventional hematoxylin and eosin (H and E) staining alone. More recently, mRNA multi-marker RT-PCR assays have been used to detect micro metastases in lymph nodes where disease was not found by either H and E or IHC techniques. During the last few years, our group has been studying the clinical value of 99mTc-MIBI scintigraphy for the evaluation of melanoma lesions. The technique was found to have the potential of detecting sub clinical recurrent disease including lymph node metastases. Therefore, the aim of the study was to compare the sensitivity of 99mTc-MIBI with that of sentinel node biopsy (SNB) with histopathological and molecular analysis, for the detection of sub clinical nodal disease