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


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.
Veronesi
U
U
Division of Senology, European Institute of Oncology, Milan, Italy. umberto.veronesi@ieo.it
De Cicco
C
C
Galimberti
V E
VE
Fernandez
J R
JR
Rotmensz
N
N
Viale
G
G
Spano
G
G
Luini
A
A
Intra
M
M
Veronesi
P
P
Berrettini
A
A
Paganelli
G
G
D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18