Management of a Patient With Metastatic Gastrointestinal Neuroendocrine Tumor and Meningioma Submitted to Peptide Receptor Radionuclide Therapy With 177 Lu-DOTATATE.

ABSTRACT: A 76-year-old woman affected by pancreatic neuroendocrine tumor previously subjected to surgery with progressive liver disease and a concomitant mild symptomatic meningioma of the left pontocerebellar angle underwent 4 cycles of peptide receptor radionuclide therapy with 177 Lu-DOTATATE. A prophylactic therapy with corticosteroids was carried out before each treatment cycle, and the neurosurgery unit was alerted in case of cerebral edema and related neurologic symptoms. A 68 Ga-DOTATOC PET/CT scan performed after the completion of the 4 cycles' treatment documented a hepatic partial response and a substantial stability of the brain mass. No neurological complications occurred during treatment and follow-up.

Usefulness of PET/CT with 18F-FDG in Patients with Differentiated Thyroid Carcinoma after Radioiodine Therapy: An Italian Multicenter Study.

BACKGROUND: our aim was to assess the diagnostic performance and clinical impact of 18F-FDG PET/CT in patients with differentiated thyroid carcinoma (DTC), previously treated with surgery and radioiodine therapy (RAI). METHODS: patients subjected to 18F-FDG PET/CT for suspected DTC recurrence in three Italian nuclear medicine units were evaluated. Two different clinical settings were identified: clinical setting 1 included patients (n = 40) that were enrolled according to the American Thyroid Association guidelines (i.e., negative 1311-WBS and Tg level > 10 ng/mL); and clinical setting 2, that encompassed subjects (n = 26) with serum Tg ≤ 10 ng/mL but morphological findings suspected of relapse. PET/CT's impact was scored as significant if it provided an indication for surgery, or led to a novel therapeutic decision. RESULTS: In total, 51/66 patients (77.3%) were 18F-FDG positive, while 15 (22.7%) were negative. PET/CT showed an overall sensitivity and specificity of 84.4% and 75%, respectively. Sensitivity was higher in clinical setting 1 (89.1%) as compared to clinical setting 2 (76.1%), although this difference was not statistically significant (p = 0.83). PET/CT influenced clinical management in 28 cases (42.4%), without a significant difference between the 2 groups of patients (p = 0.6). CONCLUSIONS: our preliminary data, although limited by the retrospective nature of the study and possible selection bias, suggest that 18F-FDG PET/CT may be utilized for the detection of DTC recurrence in different clinical settings, with a meaningful impact on clinical management.

Molecular imaging in immuno-oncology: current status and translational perspectives.

Introduction: Only 20-40% of patients respond to therapy with immune checkpoint inhibitors (ICIs). Therefore, the early identification of subjects that can benefit from such therapeutic regimen is mandatory. Areas covered: The immunobiological mechanisms of ICIs are briefly illustrated. Furthermore, the limitations of traditional radiological approaches are covered. Then, the pros and cons of molecular imaging through positron emission computed tomography (PET/CT) are reviewed, with a particular focus on 18f-fluorodeoxyglucose (18F-FDG) and PET-derived metabolic parameters. Lastly, translational perspective of radiopharmaceuticals others than 18F-FDG such as 89zirconium (89Zr) or fluorine-18 (18F) labeled monoclonal antibodies (e.g.89Zr-atezolizumab, 89Zr-nivolumab) binding to specific biomarkers are discussed. Expert opinion: Molecular imaging presents a prominent role for the management of oncological patients treated with ICIs. Preliminary clinical data indicate that PET/CT with 18F-FDG is useful for assessing the response to treatment and for the imaging of immune-related adverse effects. Nevertheless, the methodological approach (iPERCIST, PERCIMT, or others) to be used for an optimal diagnostic accuracy and patients' evaluation is still a debated issue. PET/CT with radioligands directed toward ICIs biomarkers, although is still in a translational phase, holds the promise of accurately predicting the response to treatment and revealing the acquired resistance to immunotherapy.

Diagnosis and follow-up of idiopathic retroperitoneal fibrosis: role of (18)F-FDG-PET/CT and biochemical parameters in patients with renal involvement.

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterized by fibro-inflammatory reaction surrounding ureters and other inner organs with possible secondary renal involvement. Symptoms are aspecific and recurrent phases of activity are generally associated with elevation of inflammatory indices. 18F-FDG-PET is nowadays an important tool for the detection of this disease, allowing differentiation between metabolically active tissue and fibrotic one. The purpose of this study was to investigate the role of 18F-FDG-PET in the management of IRF and to evaluate possible correlations between biochemical parameters and PET/CT findings of disease activity. We enrolled seven consecutive patients with IRF (in five histology proved the disease) observed from 2003 to 2012 (5 M:2 F, mean age 53.8 years, range 44-86 years). All patients presented with fever as first symptom; two had obstructive renal failure requiring hemodialysis; one underwent monolateral nephrectomy for parenchyma infiltration; six presented ureteral involvement; three underwent ureteral stent placement. For each patient, during a mean total follow-up of 26.5 months we evaluated serum creatinine, BUN, Hb, RBCs, WBCs, PLT, CRP, ESR. Periodic 18F-FDG-PET/CT scans (every 5.9 months-mean) were performed in all patients. Statistical evaluation was performed using "stepwise regression" analysis. Steroids and immunosuppressive agents induced a progressive normalization of PET/CT scans in all patients at the end of follow-up. Stepwise regression analysis showed that BUN, serum creatinine and CRP only if considered together, significantly correlated with SUV max (p value = 0.000003057). 18F-FDG-PET is a useful tool for clinical decision making in patient with IRF, allowing to evaluate the efficacy of the pharmacological treatment and to detect early recurrences, to modify the therapeutic approach. Acute phase reactants are not reliable alone for the management and the follow-up as they are often not concordant with metabolic assessment of the disease. In patients with ureteral involvement, CRP together with BUN and serum creatinine has a significant correlation with PET/CT results, and can help physicians in therapeutic approach, better than a single parameter.