[Intraoperative detection of sentinel lymph nodes in cutaneous malignant melanoma -- blue dye alone versus blue dye plus gamma detection].

BACKGROUND

Compared with intraoperative sentinel lymph node identification using blue dye only, the introduction of a hand-held gamma probe has improved the identification rates. In this retrospective study, further aspects related to the introduction of gamma-guided preparation are analysed in detail.

PATIENTS AND METHODS

81 patients who underwent sentinel biopsy using the blue dye technique were compared to 247 patients whose operations were guided by blue dye and gamma probe.

RESULTS

After the introduction of radio-guided surgery, the sentinel node identification rate increased from 87.7 % to 99.2 % (P < 0.00001). The number of harvested sentinel lymph nodes increased from 1.4 +/- 0.9 to 1.8 +/- 0.09 (P < 0.00001). The "clinical false-negative rate" decreased from 15.8 % to 9.6 %. The percentage of positive completion lymphadenectomy decreased from 50 % to 24.6 %. The risk of postoperative seroma decreased as a consequence of gamma guided preparation (5.1 % versus 15 %, P = 0.01). Regarding overall survival and recurrence-free survival, there were no significant differences between both groups. The 5-year-probability of nodal basin failure was 7.9 % after negative sentinel biopsy and 25.3 % after positive sentinel lymphonodectomy plus consecutive completion lymphadenectomy.

CONCLUSIONS

Combined application of blue dye and gamma-probe improved sensitivity and decreased the risk of postoperative seroma. The probability of recurrence and survival was not influenced by the technique of intraoperative sentinel node identification.