Defining the Role of PET-CT in Staging Early Breast Cancer

Defining the Role of PET-CT in Staging Early Breast Cancer:

 Abstract
Introduction. Currently, there is a lack of data on the role of combined positron emission tomography–computed tomography (PET–CT) in the staging of early invasive primary breast cancer. We therefore evaluated the role of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-PET–CT in this patient population.
Methods. We prospectively recruited 70 consecutive patients (69 women, one man; mean age, 61.9 ± 8.1 years) with early primary breast cancer for staging with ¹⁸F-FDG-PET–CT. All PET–CT images were interpreted by two readers (independently of each other). A third reader adjudicated any discrepancies. All readers had ≥5 years of specific experience. Ethics board approval and informed consent were obtained.
Results. The mean clinical follow-up was 22.7 ± 12.6 months. The primary tumor was identified with PET–CT in 64 of 70 patients. Of the unidentified lesions, surgical pathology revealed two intraductal carcinomas, one invasive tubular carcinoma, and three invasive lobular carcinomas. Undiagnosed multifocal breast disease was shown in seven of 70 patients. PET–CT identified avid axillary lymph nodes in 19 of 70 patients, compared with 24 of 70 confirmed during surgery. There were four patients who were axillary node positive on PET but had no axillary disease at surgery.
Five patients were reported with avid metastases. Two of those patients were treated for metastatic disease (nodal, lung, and liver in one and bone metastases in the other) following further imaging and clinical assessment. In the other three patients, lesions (lung, n = 1; pleural, n = 1; paratrachael node, n = 1) were subsequently diagnosed as benign lesions.
Conclusion. Integrated ¹⁸F-FDG-PET–CT may have a role in staging patients presenting with early breast cancer.

Clinical value of 18F-FDG PET-CT in detecting primary tumor for patients with carcinoma of unknown primary

Clinical value of 18F-FDG PET-CT in detecting primary tumor for patients with carcinoma of unknown primary: Publication year: 2012


Objective: 
To investigate the clinical value in detecting occult primary tumors with ¹⁸F-FDG PET-CT whole body imaging.

Methods: 
120 patients with unknown primary origin were referred for ¹⁸F-FDG PET-CT whole body imaging. All patients were performed ¹⁸F-FDG PET-CT whole body scan. PET-CT images were interpreted by visual inspection and semi-quantitative analysis (standardized uptake value, SUV). Histopathological and formal clinical follow-up findings were used to assess the value of FDG PET-CT.

Results: 
FDG PET-CT was able to detect the primary tumor in 54/120 patients (42.5%). The primary tumors were confirmed by histopathologic and formal clinical follow-up findings, and located in the head and neck (n =17), the lung (n =19), the breast (n =2), the esophagus (n =1), the stomach (n =2), the bile ducts (n =1), the pancreas (n =3), the co1on (n =3), the ovary (n =2), the prostate (n =l), others (n =3). FDG PET results were proved false positive in 9 patients (7.5%), which were located in the head and neck (n =3), the lung (n =1), the gastric (n =1), the colon (n =2), the ovary (n =1), the prostate (n =l).

During the clinical follow-up of median 32months (range, 2–45months), primary tumor was found in only 5 patients of 60 cases unidentified by PET-CT (breast cancer, gastric cancer, co1on cancer, prostate cancer and urinary tumors, respectively). The sensitivity, specificity, and accuracy of ¹⁸F-FDG PET-CT in the detection of the primary tumor site were 91.5%, 85.2%, and 88.3%, respectively.

Conclusion:
¹⁸F-FDG PET-CT whole body imaging is both a noninvasive and a very sensitive tomographic whole-body imaging modality, allowing for the detection of a primary tumor and complete tumor staging in single examination, which can contribute substantially to selecting appropriate therapeutic methods and evaluating prognosis. Perhaps ¹⁸F-FDG PET-CT whole body imaging should be used as a first-line imaging modality for patients with carcinoma of unknown primary rather than using it after other diagnostic procedures have failed to identify a primary tumor.