Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen Sensitivity of a In-111 somatostatin receptor scan with SPECT or SPECT/CT varies depending on the specific histologic type of the primary NET. For example, detection rates are >75% in small-cell-lung cancer and carcinoid metastases and 40% to 75% in insulinoma and medullary thyroid cancers [46]. MRI Abdomen In patients with a history of primary malignancy, noncontrast MRI can differentiate between malignant and benign lesions with accuracy of 71% [47]. The accuracy increases by between 83% and 91% with the addition of dynamic postcontrast sequences and further increases to 94% with addition of HBP [47,48]. In patients with a history of colon cancer, the lesion characterization on contrast-enhanced MRI is correct in 89% of cases [41]. In patients with suspected colorectal liver metastases, the combination of gadoxetate-enhanced MRI and DWI shows significantly higher accuracy (90% to 93%) for the preoperative detection of small colorectal liver metastases than DWI alone [49]. In patients with known primary cancer, ADC values can help to distinguish between metastasis and benign solid hepatic lesions [50]. Image-Guided Biopsy Liver Percutaneous image-guided biopsy may be necessary to establish the diagnosis, particularly when the imaging features on a CT or MRI examination indicate possibility of malignancy. In patients with a history of primary malignancy, 91% of biopsies are positive for malignancy, 5% of which can be different from the primary cancer [51]. Up to 6% of biopsies in patients with primary malignancy are nondiagnostic [51]. In some liver lesions, such as lymphoma, histopathologic analysis is the only technique that can make a definitive diagnosis [20]. Various techniques exist for guidance of the biopsy, and US and CT are the most commonly utilized modalities for biopsy guidance.
Liver Lesion Initial Characterization. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen Sensitivity of a In-111 somatostatin receptor scan with SPECT or SPECT/CT varies depending on the specific histologic type of the primary NET. For example, detection rates are >75% in small-cell-lung cancer and carcinoid metastases and 40% to 75% in insulinoma and medullary thyroid cancers [46]. MRI Abdomen In patients with a history of primary malignancy, noncontrast MRI can differentiate between malignant and benign lesions with accuracy of 71% [47]. The accuracy increases by between 83% and 91% with the addition of dynamic postcontrast sequences and further increases to 94% with addition of HBP [47,48]. In patients with a history of colon cancer, the lesion characterization on contrast-enhanced MRI is correct in 89% of cases [41]. In patients with suspected colorectal liver metastases, the combination of gadoxetate-enhanced MRI and DWI shows significantly higher accuracy (90% to 93%) for the preoperative detection of small colorectal liver metastases than DWI alone [49]. In patients with known primary cancer, ADC values can help to distinguish between metastasis and benign solid hepatic lesions [50]. Image-Guided Biopsy Liver Percutaneous image-guided biopsy may be necessary to establish the diagnosis, particularly when the imaging features on a CT or MRI examination indicate possibility of malignancy. In patients with a history of primary malignancy, 91% of biopsies are positive for malignancy, 5% of which can be different from the primary cancer [51]. Up to 6% of biopsies in patients with primary malignancy are nondiagnostic [51]. In some liver lesions, such as lymphoma, histopathologic analysis is the only technique that can make a definitive diagnosis [20]. Various techniques exist for guidance of the biopsy, and US and CT are the most commonly utilized modalities for biopsy guidance.