Introduction: Positron Emission Tomography with 18F-Fluorodeoxyglucose (18F FDG-PET/CT) is useful for diagnosing lymphomas, including Hodgkin's and non-Hodgkin's [1]. Its ability to detect bone marrow involvement is often compared to biopsy [2]. Traditional bone marrow biopsy has been the gold standard for diagnosing lymphomas. On the other hand, 18F FDG-PET/CT provides functional and anatomical data without surgery.

Objective: To determine the validity of 18F FDG-PET/CT in the detection of bone marrow disease in Hodgkin's and non-Hodgkin's lymphoma taking bone marrow biopsy as gold standard.

Study Design: Cross-sectional study.

Setting: This study was conducted at the Department of Nuclear Medicine, KIRAN, Karachi, Pakistan.

Duration: Six months after the approval of the synopsis from January 31, 2023 to July 30, 2023.

Materials and Methods: Patients meeting the inclusion criteria at KIRAN, Karachi, were included after getting informed consent, which explained the study protocol, hazards, and benefits. Contrast-enhanced PET/CT and bilateral/unilateral iliac crest marrow aspirate with trephine biopsy were done. Marrow biopsy was followed by PET/CT within two weeks. Interpreting Hodgkin's lymphoma marrow infiltration. PET/CT scans with localized or diffuse tracer uptake in bone/bone marrow were positive. The offered proforma was used to electronically record research data.

Results: The mean ± standard deviation of age was 33.49±14.45 years. In the gender distribution, 55 (63.2%) were classified as male, while 32 (36.8%) were classified as female. Diagnostic accuracy of 18 F-FDG-PET findings was 80.46% in diagnosis of bone marrow disease, with sensitivity 92.00%, specificity 75.81%, PPV 60.53% and NPV was found to be 95.92% by using bone marrow biopsy as gold standard.

Conclusion: It is to be concluded that 18F FDG-PET/CT holds potential for identifying bone marrow pathology in both Hodgkin's and non- Hodgkin's lymphoma. The results suggest that there is a promising ability to accurately detect patients with or without bone marrow involvement, which makes it a helpful method for assessing the condition and planning treatment without the need for intrusive procedures.

TBA