Related Experiment Videos
FDG-PET sensitivity for melanoma lymph node metastases is dependent on tumor volume
J D Wagner1, D S Schauwecker, D Davidson
1Indiana University School of Medicine, Department of Surgery, Indiana University-Purdue University at Indianapolis, Indianapolis, IN 46202, USA. jdwagner@iupui.edu
Journal of Surgical Oncology
|July 27, 2001
Summary
Positron emission tomography (PET) reliably detects melanoma lymph node metastases larger than 80 mm³. Sensitivity significantly decreases for smaller tumor volumes, especially in earlier AJCC stages.
Area of Science:
- Oncology
- Nuclear Medicine
- Medical Imaging
Background:
- Melanoma nodal metastases are a critical prognostic factor.
- Accurate detection of lymph node involvement is essential for staging and treatment planning.
Purpose of the Study:
- To establish the tumor volume threshold for successful fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging of melanoma nodal metastases.
- To correlate FDG-PET sensitivity with lymph node tumor volume and American Joint Committee on Cancer (AJCC) stage.
Main Methods:
- Retrospective review of patients undergoing FDG-PET and lymphadenectomy.
- Calculation of lymph node tumor volumes from pathological specimens.
- Correlation of PET interpretations with histology to determine sensitivity.
- Analysis of sensitivity against aggregate tumor volume and AJCC stage.
Main Results:
- FDG-PET sensitivity for all tumor volumes was 0.49.
- The 90% sensitivity threshold for detecting nodal metastases was approximately 78 mm³.
- Sensitivity was significantly lower (0.14) for tumor volumes below 78 mm³.
- PET sensitivity increased with AJCC stage (Stage I: 0.0, Stage II: 0.24, Stage III: 0.81, Stage IV: 1.0).
Conclusions:
- FDG-PET reliably detects melanoma lymph node metastases exceeding approximately 80 mm³.
- Sensitivity diminishes significantly for tumor volumes below this threshold.
- Larger tumor volumes, and thus higher detection rates, are more common in AJCC Stage III and IV melanoma.