Intraoperative lymphatic mapping and sentinel node identification with blue dye in patients with vulvar cancer

Objective. To determine the effectiveness of intraoperative lymphatic with blue dye alone as a means of localizing sentinel nodes in patients with vulvar cancer. Methods. All patients undergoing primary surgical treatment for vulvar cancer were eligible for this prospective study. Isosulfan blue dye was injected intradermally at the edge of the primary tumor closest to the adjacent groin. Bilateral dye injections and groin dissections were performed if the tumor was within 2 cm of the midline. Results. Fifty-two patients were carolled in the study between 1993 and 1999. The median age was 58 years. Eighty-seven percent of the patients had T1 or T2 lesions, and 92% had nonsuspicious lymph nodes on palpation. Sixty-seven percent of the patients had squamous cell carcinoma; the remaining patients had melanoma or adenocarcinoma. The sentinel node was identified in 46 of the 52 patients (88%), comprising 22 of the 25 patients with lateral tumors and 24 of the 27 patients with midline lesions. The sentinel node was successfully identified in 57 of the 76 (75%) dissected groins. Sentinel node identification in the groin was hampered by the effects of prior excisional biopsy vs punch biopsy (11 of 25 vs 8 of 51, P = 0.007) and by the lateral vs midline location of the tumor (22 of 25 groins vs 35 of 51 groins, P = 0.067). During the first 2 years (1993-1994), a sentinel node could not be identified in 4 of the 25 (16%) patients and 13 of the 36 (36%) groins dissected, compared with 2 of the 27 (7%) of patients treated and 6 of the 40 (15%) groins dissected from 1995 through 1999 (P = 0.034). A total of 556 nodes were removed (median, 7 per groin), of which 83 (median, 1 per groin) were sentinel. The sentinel node was not identified in 2 of the 12 groins that proved to have metastatic disease. Both events occurred in the first 2 years of the study. There were no false-negative sentinel nodes. Since 1995,we have successfully, identified the sentinel node in 16 of the 16 patients (25 of 25 groins) with T1 or T2 primary lesions, squamous histology, and nonsuspicious groin nodes on physical examination. Conclusions. Experience and careful patient selection can permit sentinel node identification with blue dye injection alone in more than 95% of patients with vulvar cancer. (C) 2001 Academic Press.