Among patients with cutaneous melanoma and clinically negative lymph nodes, preoperative imaging with single-photon emission computed tomography/computed tomography (SPECT/CT) was associated with the detection of more positive sentinel lymph nodes (SLNs) and a higher rate of disease-free survival.
The incidence of melanoma is increasing faster than any other cancer in the world, explained investigators Ingo Stoffels, MD, of the University of Essen-Duisburg in Essen, Germany, and colleagues in JAMA (2012;308:1007-1014). They pointed out that because melanoma can metastasize early into regional lymph nodes, SLN excision is probably the most important diagnostic and potentially therapeutic procedure for patients.
Noting that the recently introduced hybrid SPECT/CT three-dimensional imaging technique could help overcome the high false-negative rate of SLN excision by providing additional anatomical information to the surgeon, Stoffels and fellow researchers sought to compare metastatic node detection and disease-free survival using SPECT/CT-aided SLN excision against standard SLN excision in patients with melanoma. Their analysis involved 403 persons with cutaneous melanoma and clinically negative lymph nodes who had undergone SLN excision with or without preoperative SPECT/CT.
A total of 833 SLNs were removed—2.4 per patient in the SPECT/CT group and 1.87 per patient in the standard group. The number of positive SLNs per patient was significantly higher among the SPECT/CT patients (0.34 vs 0.21), and the local relapse rate was lower (6.8% vs 23.8%). The authors reported that the lower relapse rate prolonged 4-year disease-free survival for the SPECT/CT patients (93.9%, compared with 79.2% for persons in the standard cohort).
Stoffels’ group concluded that preoperative visualization of SLN with SPECT/CT is technically feasible and fosters the detection of additional positive SLNs. In addition, the technique enables the clinician to determine preoperatively the exact location of the SLN so that smaller incisions can be made in the head and neck area and alternative entry points can be considered.