Positron emission tomography is not useful in detecting metastasis in the sentinel lymph node in patients with primary malignant melanoma stage I and II

Abstract

The most powerful predictor for recurrence and survival in patients with primary malignant melanoma is the presence or absence of lymph node metastases. In the present study, 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) findings were compared with histopathological results of sentinel lymph node biopsy (SNB). The purpose was to determine the value of FDG-PET in predicting regional lymph node involvement in patients with primary malignant melanoma stage I and II. Forty-eight consecutive patients with primary cutaneous melanoma stage I (Breslow thickness > 1 mm) and II underwent FDG-PET scans, preoperative lymphoscintigraphy, and SNB. The FDG-PET and SNB results were interpreted independently of each other and then compared. Of the 48 patients included in the study, eight (16.7%) had a positive SNB. PET was positive in only one patient with a positive SNB, yielding a sensitivity of 13%. All other positive sentinel nodes could not be detected by metabolic FDG-PET imaging. Our study revealed that FDG-PET is obviously not an adequate screening test for subclinical and sonographically inconspicuous lymph node metastases in patients with malignant melanoma stage I and II. The low sensitivity is probably due to the small size of metastatic deposits in sentinel nodes. Therefore, SNB remains the technique of choice for evaluating the histological status of lymph node basins in patients with early-stage cutaneous melanoma.

Malignant Melanoma S3‐Guideline “Diagnosis, Therapy and Follow‐up of Melanoma”

“…Both methods, however, are inferior to sentinel lymph node biopsy in sensitivity and specificity. Prior to LND, distant metastases shall be ruled out [108,109,113,314,315].…”

Impact of 2-Deoxy-2[F-18]Fluoro-d-Glucose Positron Emission Tomography on the Management of Patients with Advanced Melanoma

“…The reported accuracy of 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-positron emission tomography (PET) in detecting melanoma metastases ranges from 80% to 100%, and FDG-PET has particular sensitivity and specificity in the detection of metastases in soft tissue and lymph nodes that are not assessable by clinical examination and have not been demonstrated by computed tomography (CT) [2Y6]. However, FDG-PET was found to be an insensitive indicator of microscopic lymph node metastases compared with sentinel lymph node biopsy in patients with early stage disease because of the small tumor volumes involved [7,8]. Information on the direct impact of FDG-PET on the clinical management of patients with melanoma is relatively limited.…”

2-Deoxy-2-[F-18]fluoro-d-glucose Positron Emission Tomography/Computed Tomography in the Management of Melanoma

“…One of the major limitations of FDG-PET noted in the published studies is the detection of regional lymph node metastasis, probably as a result of the spatial resolution of this technology. Fink et al [14] compared PET and SLNS in patients with primary malignant melanoma stages I and II. Of the 48 patients included in their study, eight (16.7%) had a positive biopsy of SLN.…”