Radio-guided ultrasound lymph node localization: feasibility of a new technique for localizing and excising nonpalpable lymph nodes ultrasound suspicious for melanoma metastases.

Identification of lymph nodes suspicious for metastases is crucial in melanoma patients during the follow-up. We propose a procedure called radio-guided ultrasound lymph node localization (RULL) for melanoma patients with ultrasound (US) suspicious, not palpable, lymph nodes. The aim of this study was to evaluate the feasibility of this technique, and to assess the efficacy of this new method. RULL was applied in 12 consecutive melanoma patients with non-palpable lymph nodes found suspicious for metastases during US follow-up. Macro-aggregates of human serum albumin labelled with diluted technetium-99m were injected into the suspected lymph node under US guidance and followed by a scintigraphy. The surgical treatment was carried out with the support of hand-held gamma-probe used for sentinel node biopsy. The tracer was correctly positioned in all 12 patients. Pathological examination revealed seven patients with metastatic lymph nodes, four with no metastatic lymph node, one patient with Hodgkin disease. No surgical complications were described. In conclusion, RULL may integrate the standard ultrasound-guided fine-needle aspiration to improve the diagnostic accuracy on US suspicious nodes and might replace the more logistically complicated wire identification or less accurate cutaneous marker identification of these nodes. Sensibility and specificity of this approach should be defined through a large multicentric study.

Pelvic sentinel lymph node biopsy in melanoma patients: is it worthwhile?

The original procedure of intraoperative lymphatic mapping by using vital blue dye initially described by Morton and colleagues in 1992 was implemented in subsequent years by the introduction of preoperative lymphoscintigraphy (LS) and intraoperative gamma detection probe to allow a better identification of sentinel nodes (SNs). However, it is common, in practice, to detect more than one radioactive node with the gamma detection probe. Whether these additional lymph nodes represent true SNs is not yet clear. The aims of this study are: to investigate the role of pelvic sentinel node biopsy in recurrent pelvic disease in those patients with negative inguinal SN, having one or more deep hot spots identified by preoperative LS (follow-up group). One hundred and four stage I/II melanoma patients with primary tumor of the lower limb and lower trunk were enrolled in a restrospective study at the European Institute of Oncology, Milan, Italy, between 2000 and 2007. All patients presented hot spots both in superficial (groin) and deep (iliac-obturator) areas during dynamic LS. The study population consisted of 35 men and 69 women with a median age of 57 years at the time of diagnosis. The median follow-up period was 49 months (SD 22.4; range, 10-98 months). Of the 104 patients, 83 had a negative SN (80%). All sentinel-lymph-node-positive patients underwent superficial and deep inguinal dissection. Two patients (2.4%; 95% confidence interval: 1.5-8.8%) with negative SNs had pelvic recurrence. Among patients who underwent ilioinguinal dissection, three (14%; 95% confidence interval: 4-35%) had positive pelvic lymph nodes. After a 60-month follow-up, 79% of patients were alive and 66% were disease free. In SN-negative patients, disease-free survival was 69% and in SN-positive patients 53%. No significant difference was found by SN status (log-rank P values 0.15). Even if the sample size of our study cannot bring to conclusive results, and further studies are needed, it might be possible that harvesting pelvic SN in those patients with pelvic hot spots at LS could modify the natural history of melanoma patients in terms of pelvic recurrence and disease free survival. We recommend to improve our knowledge in the role of pelvic sentinel node in the natural history of melanoma.