Info

_•-■■vl-l:__- Jfyfc_ .i.- lll_2Í9BC:_SKiüIl__

Coronal FDG Images

Figure 9. Coronal 18F-FDG images in a patient with squamous carcinoma of the lung metastatic to the liver. The large hepatic metastasis (arrow) has a photopenic center suggesting a central area of necrosis. (Courtesy of ADAC Labs and Dr. A. Alavi, University of Pennsylvania, Philadelphia, USA.)

management changes in 67% of patients based on the PET scan. In addition there are good data suggesting that the appropriate use of PET imaging in patients with NSCLC can produce significant savings to the healthcare system by avoiding unnecessary—and unhelpful—interventions.

FDG imaging should be the standard of care in the management of patients with NSCLC at presentation and probably for assessment of possible relapse.

Lymphoma

Lymphomas make up 8% of all malignancies. Hodgkin's disease (HD) is characterized by the presence of Reed-Sternberg cells. Four histologic subtypes have been described: nodular sclerosing (40-60%), lymphocyte predominant (2-10%), mixed cellularity (20-40%) and lymphocyte depleted (2-15%). Spread is characteristically sequential from nodal group to nodal group and intrathoracic disease is common. Non-Hodgkin's lymphoma (NHL) is a more heterogeneous group of tumors, defined as high, intermediate or low grade by the Modified Working Classification. High grade tumors are aggressive with a short median survival if untreated. Low grade tumors are more indolent with a longer median survival.

Staging for both HD and NHL uses the Ann Arbor system. The presence of systemic symptoms (fever, night sweats, weight loss > 10% body weight) or pruritus are considered poor prognostic indicators. Treatment, according to stage and classification, is by chemotherapy and/or radiation therapy. Peripheral stem cell or autologous bone marrow transplantation have proven effective salvage therapy options and antibody therapies are now completing Phase III trials. To date one agent, 99Y-ibritumomab tiuxetan (Zevalin®) has received FDA approval for treatment of low-grade CD20+ P-cell NHL.

Lymphoma is, therefore, a treatable cancer for which accurate staging, demonstration of therapeutic effectiveness and early detection of recurrence are key elements of successful management strategies. Imaging with gallium has conventionally been the nuclear medicine investigation used in the management of this patient population; however, the Centers for Medicaid Services (CMS, formerly

0 0

Post a comment