PT - JOURNAL ARTICLE AU - Kumar, Rajender AU - Krishnaraju, Venkata AU - Mittal, Bhagwant AU - Bhattacharya, Anish AU - Singh, Harmandeep AU - Prakash, Gaurav TI - <strong>Role of Fluorodeoxyglucose Positron emission tomography/computed tomography and PET/CT guided directed core needle biopsy during the different management stages of lymphoma</strong> DP - 2022 Aug 01 TA - Journal of Nuclear Medicine PG - 3130--3130 VI - 63 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/63/supplement_2/3130.short 4100 - http://jnm.snmjournals.org/content/63/supplement_2/3130.full SO - J Nucl Med2022 Aug 01; 63 AB - 3130 Introduction: F-18 FDG PET/CT plays a significant role in managing lymphoma at various stages, including establishing the diagnosis, staging, and interim response assessment and assessing remission after completing the first-line treatment program. Identifying the correct histological subtype is paramount for predicting a case and selecting the best available anticancer treatment. CT imaging is inept in identifying early extranodal organ involvement by lymphoma. Combined use of both these modalities may provide an incremental value over pre-existing management algorithms in lymphoma management. Methods: In this ethically approved study, we prospectively recruited the participants who underwent PET/CT and metabolic core needle biopsy during the different management stages of lymphoma (to diagnose clinically suspected cases, staging or post-treatment evaluation) from October 2014 to December 2021. Two qualified nuclear medicine physicians reviewed all the PET/CT. An FDG avid lesion was considered as PET-positive during initial workup for clinically suspected cases of lymphomatous etiology. Follow-up FDG PET scans during interim evaluation or at the end of therapy were interpreted according to the Deauville scale 5 point scoring (DS) system. No FDG uptake – score 1, FDG avidity ≤ mediastinal blood pool- Score 2, FDG avidity &gt; mediastinal blood pool but ≤ the liver activity –score 3, FDG avidity moderately &gt;liver –score 4, if FDG avidity markedly increased than liver –score 5a and any new FDG avid lesion –score 5b. A DS ≤3 was considered PET negative, while DS 4 and 5 were defined as PET-positive. The PET/CT-guided biopsy was performed using an automated robotic arm system based on the PET/CT findings. Society of interventional radiology consensus guidelines was followed for the procedures. The diagnostic performance was assessed by the histopathological findings obtained. Procedure-related complications were also recorded.Results: Two-hundred thirteen participants (137 males) were recruited in the study. Fifteen participants refused to undergo metabolic biopsy procedures. Of 198 procedures, 93/198(47%) were performed for diagnosis, 10/198(5%) for staging, 83/198(42%) for post-treatment evaluation and 12/198 (6%) for recurrence evaluation. The biopsy sites were nodal (54%) and extranodal (46%). The procedure had a diagnostic yield of 98%. Lymphoma was diagnosed in 64/93 (69%) participants with clinical suspicion, while the disease was upstaged during staging (n=10). At post-treatment evaluation, 9/10 (90%) participants with Deauville score (DS) ≤3 had no lymphoma. Lymphoma was diagnosed in 54% of participants with DS-4, 100% with DS-5a and 69% with DS-5b. None of the participants reported any major complications requiring termination of procedure or hospitalization. Among the patients who underwent lung biopsies, two patients developed a minimal pneumothorax (n=2/19, 11%) of class B or lower and were managed conservatively.Conclusions: Metabolic core-needle biopsy in different management stages of lymphoma has a high diagnostic yield. Isolated distant sites of FDG uptake should be sampled for adequate disease staging. At the end of treatment, the DS-5a score is highly suggestive of residual disease, which may require treatment intensification or innovative therapeutic approaches. However, participants with DS4 and DS-5b require histopathological confirmation before any change in treatment strategy to rule out false-positive.