Metabolic Imaging Identifies Non-Hodgkin’s Lymphoma Infiltrating Heart
A67-year-old man was diagnosed with a lymphoblastic non-Hodgkin’s lymphoma and was found to have tumor infiltrating the right atrium, the ventricular septum, and the left ventricle. The tumor was imaged by TEE and MRT, and the diagnosis was confirmed by biopsy. After completion of six courses chemotherapy with CHOEP, no residual wall motion abnormalities or contrast changes were detectable by TEE. A follow-up MRT was not possible after pacemaker implantation became necessary because of AV conduction abnormalities. A CT scan was performed but could not be evaluated because of metal artifacts. A PET scan with FDG was performed to exclude residual tumor mass.
Non-Hodgkin’s lymphomas exhibit an enhanced FDG uptake, as do most malignant tumors.1 In contrast to myocardial tissue, tumor FDG uptake is independent of plasma substrate levels and insulin stimulation, allowing identification of tumor infiltration. Therefore, the patient was fasted >12 hours before the FDG study to minimize glucose uptake in normal myocardium. Before the FDG study, a flow study with [13N]ammonia was performed to document myocardial perfusion.
The images (Figure⇓, A) show the ammonia and FDG studies after six courses of CHOEP. The perfusion study demonstrated a homogeneous perfusion of the left ventricle, but the FDG study revealed evidence of viable tumor in the lateral wall of the left ventricle. There was focally enhanced tracer accumulation in the mediastinum representing involved lymph nodes. The FDG uptake was documented as the SUV, which is the maximum radioactivity concentration in a region of interest divided by the injected dose normalized to the patient’s weight at 30 to 60 minutes after injection. On the basis of these results, the patient received radiotherapy.
Two weeks after completion of radiotherapy, the PET study (Figure⇑, B) was repeated. Progress of the tumor with extensive tumor masses in the lower mediastinum infiltrating the heart, perihilar lymphatic tissue, and left lower lobe was demonstrated. The SUV in the known lesion in the left ventricle had decreased 19% from 7.9 to 6.4, which represented partial tumor devitalization by radiotherapy. In the mediastinum, the SUV increased 72% as a marker of tumor progress. The perfusion of the left ventricle was again normal. Two weeks after this study, the patient died of cerebral infarction; the tumor extension shown by the PET study was confirmed histologically at autopsy.
Selected Abbreviations and Acronyms
|CHOEP||=||cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone|
|MRT||=||magnetic resonance tomography|
|SUV||=||standardized uptake value|
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to Dr Hugh A. McAllister, Jr, St Luke’s Episcopal Hospital and Texas Heart Institute, 6720 Bertner Ave, MC1–267, Houston, TX 77030.
- Copyright © 1998 by American Heart Association
Lapela M, Leskinen S, Minn HR, Lindholm P, Klemi PJ, Söderström KO, Bergman J, Haaparanta M, Ruotsalainen U, Solin O, Joensuu H. Increased glucose metabolism in untreated non-Hodgkin’s lymphoma: a study with positron emission tomography and fluorine-18-fluorodeoxyglucose. Blood. 1995;86:3522–3527.