SPECT/CT detects metastatic nodes in melanoma

Sep 17 2012

By medwireNews Reporters

The preoperative use of single-photon emission CT (CT) plus CT (SPECT/CT) imaging improves the detection of metastatic lymph nodes over standard lymphoscintigraphy, research shows.

In addition, SPECT/CT-aided sentinel lymph node (SLN) excision results in an increase in disease-free survival among patients with lymph node-negative melanoma, demonstrate results published in the Journal of the American Medical Association.

"The preoperative visualization of SLN with SPECT/CT is technically feasible and facilitates the detection of additional positive SLNs," report researcher Joachim Klode (University School of Medicine Essen-Duisburg, Germany) and colleagues.

Significantly more SLNs per patient were detected in the 149 patients in the SPECT/CT cohort than in the 254 patients who underwent standard preoperative lymphoscintigraphy (2.40 vs 1.87).

When SLN excisions were performed using the 3D SPECT/CT, 0.34 positive lymph nodes per patient were detected. By contrast, 0.21 positive lymph nodes were detected when standard SLN excisions were performed, a statistically significant difference.

At 4 years, disease-free survival in the SPECT/CT-aided treatment arm was significantly higher at 93.9% compared with 79.2% in the standard SLN excision arm. The use of SPECT/CT was significantly predictive of disease-free survival in multivariate analysis, with a significantly hazard ratio of 4.1.

Patients in both treatment arms were similar in terms of age, tumor depth, and ulceration of the primary tumor. In terms of tumor location, 43.4% had tumors in the torso, 41.9% had tumors in the extremities, and 9.4% had tumors in the head or neck.

Surgeons were able to excise SLNs for tumors in the head or neck in 23.5% of patients who underwent preoperative SPECT/CT imaging, compared with just 2.0% of patients treated with the standard procedure.

The SPECT/CT versus the standard approach also allowed for the detection of sentinel lymph nodes in obese patients.

The reported false-positive rate in the SPECT/CT treatment arm was 6.8% compared with 23.8% in the standard-treatment arm.

Among the patients undergoing SPECT/CT, alterations to the surgical procedure were made as a result of the 3D imaging in 22.1% of cases.

"The use of this technique offers the physician the preoperative possibility of determining the exact location and visualization of the SNL," write Klode and colleagues.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.