A comparative study on the value of FDG-PET and sentinel node biopsy to identify occult axillary metastases

Ann Oncol. 2007 Mar;18(3):473-8. doi: 10.1093/annonc/mdl425. Epub 2006 Dec 12.


Background: Sentinel node biopsy (SNB) has become a standard treatment in staging axillary lymph nodes in early breast cancer. SNB, however, is an invasive procedure and is time-consuming when the sentinel node is analysed intra-operatively. Breast cancer is frequently characterised by increased 2-fluoro-2-deoxy-D-glucose uptake and many studies have shown encouraging results in detecting axillary lymph node metastases. The aim of this study was to compare SNB and -positron emission tomography (-PET) imaging, to assess their values in detecting occult axillary metastases.

Patients and methods: In all, 236 patients with breast cancer and clinically negative axilla were enrolled in the study. 18-FDG-PET was carried out before surgery, using a positron emission tomography (PET)/computed tomography scanner. In all patients, SNB was carried out after identification through lymphoscintigraphy. Patients underwent axillary lymph nodes dissection (ALND) in cases of positive FDG-PET or positive SNB. The results of PET scan were compared with histopathology of SNB and ALND.

Results: In all, 103 out of the 236 patients (44%) had metastases in axillary nodes. Sensitivity of FDG-PET scan for detection of axillary lymph node metastases in this series was low (37%); however, specificity and positive predictive values were acceptable (96% and 88%, respectively).

Conclusions: The high specificity of PET imaging indicates that patients who have a PET-positive axilla should have an ALND rather than an SNB for axillary staging. In contrast, FDG-PET showed poor sensitivity in the detection of axillary metastases, confirming the need for SNB in cases where PET is negative in the axilla.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Axilla
  • Breast Neoplasms / diagnostic imaging
  • Breast Neoplasms / pathology*
  • Breast Neoplasms / surgery
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Lymph Node Excision
  • Lymph Nodes / diagnostic imaging
  • Lymph Nodes / pathology*
  • Lymph Nodes / surgery
  • Lymphatic Metastasis
  • Middle Aged
  • Neoplasm Staging
  • Positron-Emission Tomography
  • Predictive Value of Tests
  • Radiopharmaceuticals*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Sentinel Lymph Node Biopsy*


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18