All Publications

  • Neuroendocrine metastasis to the thyroid from unknown primary and extrathyroidal disease response to peptide receptor radionuclide therapy. Radiology case reports Khessib, T., Khessib, S., Berry, G., Aparici, M. 2023; 18 (11): 3945-3948


    Neuroendocrine tumor (NET) metastasis to the thyroid is rare, and its presentation as the first manifestation of primary malignancy elsewhere is even more uncommon. We present a case of a 41-year-old female who underwent biopsy of enlarging thyroid nodules with findings suspicious for medullary thyroid cancer (MTC). Subsequent thyroidectomy demonstrated NET of unknown primary in the left lower lobe. Immediate workup with 68Ga-DOTATATE-PET/CT revealed abnormal somatostatin receptor (SR) expressing lesions in the liver, right cervical nodes, thoracic paravertebral soft tissue, precoccygeal soft tissue, and right acetabulum concerning for sites of neuroendocrine malignancy. Due to disease progression while on octreotide injections, a decision was made at the multidisciplinary NET board for the patient to receive peptide receptor radionuclide therapy (PRRT) which includes 4 cycles of 77Lu-DOTATATE (Lutathera). The patient had no side effects nor toxicities during the 8 months of PRRT and achieved a partial treatment response in the early post-treatment scan at 6 weeks. This case illustrates the importance of distinguishing NET metastasis to the thyroid from MTC to ensure appropriate workup and treatment as well as predict the response of neuroendocrine malignancies to PRRT based on the visualized overexpression of SR in the SR-PET scans, despite the organ of origin.

    View details for DOI 10.1016/j.radcr.2023.07.044

    View details for PubMedID 37680654

  • Retroperitoneal Inflammation Detected on FDG PET/CT in Patient on Long-Term Immunotherapy. Clinical nuclear medicine Khessib, T., Franc, B., Yang, E., Moradi, F. 2023


    ABSTRACT: A 68-year-old man with a history of pulmonary adenocarcinoma on maintenance pembrolizumab presented for surveillance imaging. 18F-FDG PET/CT demonstrated new ill-defined right retroperitoneal and presacral soft tissue stranding with associated FDG uptake suggestive of inflammation. Biopsy results revealed fibroadipose tissue with extensive lymphoplasmacytic inflammation concerning for immunotherapy-related toxicity. The patient was subsequently taken off pembrolizumab, which he had been on for approximately 3 years. Recognition of immunotherapy-related adverse effects and how they can manifest on 18F-FDG PET/CT is important for prompt cessation of treatment.

    View details for DOI 10.1097/RLU.0000000000004513

    View details for PubMedID 36728374

  • Testicular FDG Uptake on PET/CT in Patients with Lymphoma: Correlation with Age. Current problems in diagnostic radiology Khessib, T., Itani, M., Hippe, D., Akaike, G., Bermo, M., Zare, M., Behnia, F. 2021


    The purpose of this observational study was to investigate whether the standard uptake value (SUV) measurement has practical utility in distinguishing secondary testicular involvement from physiologic uptake in patients with lymphoma. A Radiology Information System (RIS) search was conducted for all PET/CT studies performed from 2010-2016 on adult male patients with a diagnosis of lymphoma. Patients with clinical or pathologic diagnosis of testicular lymphoma were excluded to undergo a separate analysis. PET/CT images of 606 patients with 1087 scans, in which 2045 testes were included in the field of view, were reviewed and measurements were performed for standardized uptake values of both testicles (SUVmax) as well as of the liver (SUVmax and SUVmean). The mean SUVmax of the testicles was 3.75 ± 0.90 (range 1.16-8.38). The mean ratio of testis SUVmax / liver SUVmean (T/L) was 1.78 ± 0.43. Trends in SUVmax and age were significant for a negative correlation by a small magnitude of 0.066 per 10 years (P < 0.001). T/L had similar changes with significant low magnitude decrease with increasing age (0.059 per 10-year increase, P < 0.001). In our separate analysis of 3 patients with clinical or pathology proven testicular lymphoma, the average pathologic SUVmax was 13.47 (range 11.39-15.97). This study has the largest known sample size for quantifying physiologic uptake in the testes. SUV measurements to quantify F-18 Fluorodeoxyglucose (FDG) uptake on PET/CT likely have practical utility in discriminating between physiologic and pathologic uptake of FDG in cases of secondary testicular lymphoma.

    View details for DOI 10.1067/j.cpradiol.2021.07.003

    View details for PubMedID 34756775