FDG PET/CT can identify if there are any lesions of high FDG avidity, suspicious for transformation, that have developed and can direct biopsy to an accessible highly FDG-avid lesion.įocal FDG avidity within the bone or bone marrow is highly sensitive for osseous lymphoma in FDG-avid lymphomas. This is valuable for patients for whom malignant transformation from a low-grade lymphoma to a more aggressive high-grade lymphoma is suspected. Values between 10 and 20 are usually high-grade lymphomas, but there is some overlap. 13.2 ), whereas SUV less than 10 is typically a low-grade lymphoma (see Chapter 13, Fig. As a rule of thumb, a pretreatment SUV of greater than 20 indicates high-grade lymphoma (see Chapter 13, Fig. However, after lymphoma has been diagnosed by biopsy, the SUVmax can be used to help distinguish low-grade from high-grade lymphoma. The intensity of FDG avidity (the standardized uptake value max of the node) cannot be used to diagnosis lymphoma in lieu of a biopsy. A biopsy is needed to confirm that FDG-avid nodes represent lymphoma.

These consensus guidelines state that FDG PET/CT should be recommended for the initial staging of FDG-avid nodal lymphomas. These guidelines were produced following an International Conference on Malignant Lymphoma held in Lugano, Switzerland. The most recent recommendations for the use of FDG PET/CT are referred to as the Lugano Classification. In non–FDG avid lymphomas, contrast-enhanced CT is the standard imaging modality. FDG PET/CT would be useful in these lymphomas only if the tumor in an individual patient was proven to be FDG avid. Some lymphomas have variable FDG avidity, including chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma, and marginal zone lymphoma.

The vast majority of lymphomas are FDG avid, including the most common lymphomas, Hodgkin lymphoma (HL), diffuse large B-cell lymphoma(DLBCL), and follicular lymphoma. FDG PET/CT has become the primary imaging modality for staging and treatment response in patients with FDG-avid lymphomas.

Shotty axillary lymph nodes