Role of 2-(fluorine-18) Fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in Initial Staging and Bone Marrow Involvement Prediction in Patients with Newly Diagnosed Lymphoma in Correlation with Bone Marrow Study.

Background: Lymphoma is a common malignant proliferative disease in which bone marrow infiltration will upstage the disease and thus affect prognosis of the disease. As of now bone marrow biopsy is considered as a reference standard to find out bone marrow involvement in lymphoma. Performing an invasive and painful intervention in all newly diagnosed lymphoma patients is controversial. PET-CT is a non-invasive technique that gives functional information about the cells using the glucose metabolism. It can detect early bone marrow and extra medullary organ involvement which can lead to restaging of the disease. These advantages make PET-CT a valuable adjunct in diagnosis of lymphoma. Aims and Objectives: Our study aims to evaluate the usefulness of 18 F-FDG PET-CT, a non-invasive, semi quantitative whole body imaging technique for detection of early bone marrow and extra medullary organ involvement in lymphoma patients which in turn can obviate the need for bone marrow study (BMS). The primary objective of study is to categorise FDG uptake in bone marrow as diffuse /unifocal /multifocal / no uptake and to correlate pattern of FDG uptake to bone marrow study. Our study also assesses the role of FDG PET/CT in staging of lymphoma. Materials and Methods: Thirty patients with newly diagnosed lymphoma in the age group 18 to 75 years of both sexes within 3 months of diagnosis and who have not been started on any treatment was included in the study. Marrow uptake on FDG PET/CT has been categorized as diffuse, unifocal, multifocal and no uptake. Agreement between bone marrow study and FDG PET/CT has been assessed by reliability analysis using Cohen's kappa. Sensitivity, specificity, PPV, NPV of PET/CT in detecting marrow involvement have been calculated. Results: The sensitivity, specificity, PPV, NPV and accuracy of 18 F-FDG PET-CT in detecting marrow involvement of lymphoma cases are 86.6%, 77.7%, 68.4%, 91.3% and 80.9% respectively. 18 F-FDG PET-CT detected bone marrow involvement in 86.6% (13 out of 15 total positive cases) cases of lymphoma which included both HL and NHL. Reliability analysis using Cohen's kappa is used to test the agreement between bone marrow study and 18F-FDG PET/CT. k value of 0.6 was obtained which showed a moderate agreement between bone marrow study and 18F-FDG PET/CT in marrow assessment. Conclusion: 18F-FDG PET/CT is a highly sensitive imaging modality which can pick up extra-nodal organ and BMI in patients with lymphoma and can upstage the disease and alter treatment strategies. PET-CT cannot completely replace the bone marrow study. However, being an invasive painful procedure, BMB can be avoided in cases with unifocal or multifocal marrow involvement on PET-CT.

Orbital Plasmablastic Lymphoma: A Rare Variant of Diffuse Large B-Cell Lymphoma Staged and Followed Up by 18F-FDG PET/CT.

ABSTRACT: Plasmablastic lymphoma (PBL) is a rare and aggressive variant of diffuse large B-cell lymphoma which is associated with HIV infection. Recently, it has also been reported in immunocompetent and solid organ transplant patients. PBL commonly presents in extranodal regions such as oral cavity, digestive tract, and skin. Orbital involvement by PBL is extremely rare with only few reports in the literature. We present a case of PBL involving the bilateral orbits in an immunocompetent patient with 1-year follow-up on 18F-FDG PET/CT scan.

Diffuse White Adipose Tissue 18F-FDG Uptake-An Unusual Finding on 18F-FDG PET/CT.

ABSTRACT: Brown adipose tissue of cervical, supraclavicular, and paravertebral regions can show increased FDG uptake. But human white adipose tissue (WAT) shows negligible FDG uptake on 18F-FDG PET/CT scan. We present a case of carcinoma cervix treated with concurrent chemoradiation. 18F-FDG PET/CT shows altered biodistribution of FDG with intense FDG uptake throughout the WAT. Later on, patient confirmed taking herbal medication for herpes zoster infection, which could contain corticosteroids, resulting in enhanced WAT uptake of 18F-FDG.

Incidentally Diagnosed Esophago-Pulmonary Fistula on 18F-FDG PET/CT in a Case of Carcinoma Esophagus: A Life-Threatening Emergency.

ABSTRACT: Esophago-pulmonary fistulas are very less reported in literature. 18F-FDG PET/CT scan is routinely used for evaluation of patients of carcinoma esophagus. We present a case of carcinoma esophagus with acquired esophago-pulmonary fistula diagnosed on 18F-FDG PET/CT scan.

Metabolic Bone Superscan in Carcinoma Breast with Occult Graves' Disease: Looking Beyond Skeletal Metastases.

Extrathyroidal manifestations of autoimmune thyroid disorders include thyroid-associated ophthalmopathy, thyroid dermopathy, and thyroid acropachy. Thyroid acropachy is an extreme manifestation of autoimmune thyroid disorder characterized by clubbing and swelling of fingers and toes, with or without periosteal reaction of the distal bones. We present a 50-year-old woman, posttreatment for carcinoma breast (6 years back) and referred for bone scan for generalized body ache. Bone scan findings resulting in detailed clinical evaluation prompted toward the suspicion of a thyroidal disease with ultimate diagnosis of Graves' disease.