Sir Peter MacCallum Department of Oncology - Research Publications
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ItemNo Preview AvailableThe Role of 68Ga-DOTA-Octreotate PET/CT in Follow-Up of SDH-Associated Pheochromocytoma and Paraganglioma(ENDOCRINE SOCIETY, 2019-11-01)Purpose: Germline succinate dehydrogenase (SDHx) mutation carriers, especially SDHB, are at increased risk for malignancy and require life-long surveillance. Current guidelines recommend periodic whole-body MRI imaging. We assessed the incremental value of 68Ga-DOTA-octreotate (GaTate) positron emission tomography (PET)/CT compared with conventional imaging in such patients. Methods: SDHx mutation carriers who had GaTate PET/CT were retrospectively reviewed. Detection of lesions were compared with MRI or CT on a per-patient and per-lesion basis. Proof of lesions were based on histopathology or clinical/imaging follow-up. Results: Twenty consecutive patients (median age, 46 years; 10 males) were reviewed. Fourteen patients had SDHB, four, SDHD, one SDHC, and one SDHA mutation. Fifteen had prior surgery and/or radiotherapy. Indications for PET/CT were as follows: 7 patients for surveillance for previously treated disease, 9 residual disease, 2 asymptomatic mutation carriers, and 2 for elevated catecholamines. Median time between modalities was 1.5 months. GaTate PET/CT had higher sensitivity and specificity than conventional imaging. On a per-patient basis: PET/CT sensitivity 100%, specificity 100%; MRI/CT 85% and 50%. Per-lesion basis: PET/CT sensitivity 100%, specificity 75%; MRI/CT 80% and 25%. PET/CT correctly identified additional small nodal and osseous lesions. MRI/CT had more false-positive findings. Change of management resulted in 40% (8/20 patients): 3 received localized treatment instead of observation, 1 changed to observation given extra disease detected, 4 with metastases had radionuclide therapy. Conclusions: GaTate PET/CT provided incremental diagnostic information with consequent management impact in SDHx-pheochromocytoma and paraganglioma. Incorporating this modality as part of a surveillance program seems prudent. Further research is needed to define the optimal surveillance strategy including use of MRI.
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ItemThe INTERNET STUDY: A phase II study of everolimus in patients with fluorodeoxyglucose (18F) positron-emission tomography positive intermediate grade pancreatic neuroendocrine tumors(WILEY, 2020-06)AIMS: This multicenter phase II trial evaluates the efficacy of everolimus in poor prognosis grade 2 (G2) pancreatic neuroendocrine tumors (PNETs), defined by 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) avidity. FDG-PET avidity in NETs is associated with a significantly higher risk of death, outperforming Ki-67 index or liver metastases as a poor prognostic factor. We hypothesized that everolimus has efficacy in patients with FDG-PET-avid G2 PNETs and prospectively evaluated progression-free survival (PFS) and response in the first-line setting. METHODS: Patients with FDG-PET-avid G2 advanced PNET received everolimus 10 mg daily until disease progression. Patients were staged every 12 weeks with CT/MRI and FDG-PET and every 24 weeks with Gallium 68 (68Ga) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE, GaTate) PET. The primary endpoint was PFS at 6 months. Overall survival rate, PET/structural imaging response and toxicity were also measured. RESULTS: Nine patients were accrued from December 2012 to February 2015. Median treatment duration was 13.8 months. The estimated PFS rate at 6 months was 78%. The best response on CT/MRI was stable disease in nine patients (100%) and partial response on FDG-PET in five patients (55.5%). Treatment-related adverse effects were consistent with previous studies of everolimus. CONCLUSION: Everolimus is active with prolonged disease control in poor prognosis FDG-avid G2 PNETs. Treatment individualization based on functional imaging warrants further evaluation.