Introduction. In recent years the indications for organ preserving surgery in patients with kidney cancer have expanded. The main criteria of organ sparing surgery are local recurrence rate and long-term survival rate. The reason of local recurrence is nonradical resection performed due to no possibility of clear visualization of tumor absence in surgical margin and in biopsy places. Therefore the development of methods capable for tumor visualization and as a result performing precise biopsy from suspicious areas is of current concern. One of these methods is fluorescence diagnostics (FD)

Materials and methods. The study included 20 patients with kidney cancer who underwent partial nephrectomy under fluorescent control in the Institute if Urology. All patients had T1a – T1b clinical stages. As a photosensitizer we used home product Alasens (5-aminolevulinic acid).

Results: During the surgery, in 15 patients (75%) no positive fluorescence of surgical margins was detected which was confirmed by histological examination. In 5 patients (25%) in FD fluorescence of surgical margins were marked, with 1 patient tumor tissue in the area of resection confirmed morphologically.

FD sensitivity was 100%, specificity – 79%.

Conclusion: The Alasens selectively accumulates in tumor tissue. This allows the surgeon to visually assess the surgical margin of the resection and to exclude the possibility of residual tumor, thereby reducing the incidence of local recurrence and improving disease-free survival rates.