18F-FDG PET/CT as a staging procedure in primary stage II and III breast cancer: comparison with conventional imaging techniques

Abstract

The aim of the present study was to investigate if 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) outperforms conventional imaging techniques for excluding distant metastases prior to neoadjuvant chemotherapy (NAC) treatment in patients with stage II and III breast cancer. Second, we assessed the clinical importance of false positive findings. One hundred and fifty four patients with stage II or III breast cancer, scheduled to receive NAC, underwent an 18F-FDG PET/CT scan and conventional imaging, consisting of bone scintigraphy, ultrasound of the liver, and chest radiography. Suspect additional lesions at staging examination were confirmed by biopsy and histopathology and/or additional imaging. Metastases that were detected within 6 months after the PET/CT scan were considered evidence of occult metastasis, missed by staging examination. Forty-two additional distant lesions were seen in 25 patients with PET/CT and could be confirmed in 20 (13%) of 154 patients. PET/CT was false positive for 8 additional lesions (19%) and misclassified the presence of metastatic disease in 5 (3%) of 154 patients. In 16 (80%) of 20 patients, additional lesions were exclusively seen with PET/CT, leading to a change in treatment in 13 (8%) of 154 patients. In 129 patients with a negative staging PET/CT, no metastases developed during the follow-up of 9.0 months. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT in the detection of additional distant lesions in patients with stage II or III breast cancer are 100, 96, 80, 100, and 97%, respectively. FDG PET/CT is superior to conventional imaging techniques in the detection of distant metastases in patients with untreated stage II or III breast cancer and is associated with a low false positive rate. PET/CT may be of additional value in the staging of breast cancer prior to NAC.

The Role of <sup>18</sup>F-FDG-PET/CT in the Management of Patients with High-Risk Breast Cancer: Case Series and Guideline Comparison

“…In the present study the change of TNM-stage after FDG-PET/CT resulted in an adjustment of treatment in 25% of patients. Koolen et al found that in 8% of cases treatment was adjusted after FDG-PET/ CT, but the difference between these numbers can be accounted for by the inclusion of stage III and IV breast carcinoma in our study (and stage II and III in Koolen's) [8]. Furthermore, one of our patients received a curative instead of a palliative treatment, which can be seen as a downstaging of treatment, while the patients of Koolen were all upstaged.…”

“…This is far better than conventional imaging (43% and 98% respectively), but comparable to CT (83% and 84%) [4]. Koolen et al recently compared FDG/PET-CT with conventional imaging in 154 patients, resulting in a sensitivity of 100%, specificity of 96%, positive predictive value of 80%, negative predictive value of 100% and an accuracy of 97% [8].…”

“…The Dutch guideline for breast cancer recommends the use of FDG-PET/CT in assessing metastatic disease of primary grade III breast carcinoma [5]. This is based on research by several groups [3] [4] [6]- [8]. For example, Fuster et al conducted a prospective study in 60 patients, showing a sensitivity of 100% and a specificity of 98% for FDG-PET (without CT), compared with a sensitivity of 60% and specificity of 93% in conventional imaging [3].…”

Present and future role of FDG-PET/CT imaging in the management of breast cancer

“…For the initial staging work-up, many conventional imaging modalities, such as X-ray mammography, MR mammography, chest plain radiography, bone scintigraphy, and breast, axillary and liver ultrasonography, have been widely utilized. In recent years, several groups have evaluated the clinical role of FDG-PET/CT for pretreatment evaluation of breast cancer in comparison with conventional imaging tools [18,39,[43][44][45][46][47][48][49][50][51][52][53][54] (Table 2). These studies revealed that FDG-PET/CT is generally helpful, but particularly valuable for detection of extra-axillary (infraclavicular, supraclavicular and internal mammary) nodal metastasis and occult distant metastasis relative to conventional modalities, especially in patients with inflammatory breast cancer [43,46,47] and stage II-III disease [18, Fig.…”

FDG-PET/CT for systemic staging of patients with newly diagnosed breast cancer

“…The case is different in higher-risk BC patients in whom initial workup would usually comprise several imaging studies including ultrasonography of accessible lymph node basins, CT of the thorax and abdomen (or liver ultrasonography) and bone scan. In many studies, FDG-PET/CT outperformed conventional imaging for examining extra-axillary nodes, chest, abdomen and bone in a single session [5,6]. The larger evaluations have been performed in locally advanced and inflammatory BC [6][7][8] which are usually regarded as equivalent to stage III cancer of the AJCC classification [9].…”