Diagnosis and radioguided surgery with 111In-pentetreotide in a patient with paraneoplastic Cushing's syndrome due to a bronchial carcinoid

Abstract

In a 28-year-old man with Cushing's syndrome, studies investigating a hypophyseal and/or adrenal origin of the disease, including computed tomography and magnetic resonance imaging, were negative.In agreement with reports showing somatostatin receptors on the cell membrane of ectopically secreting ACTH tumours, scintigraphy was performed after intravenous injection of 111 MBq 111 Inpentetreotide (OCT). The radiolabelled OCT scan showed a small focal area of intense uptake at the inferior lobe of the right lung.Subsequent radioguided surgery located and defined a small mass (1:8 × 1:4 × 1:6 cm). The probe pinpointed the mass to the right inferior chest lobe, with a tumour/normal tissue count ratio of 6 : 1 and tumour/hilar normal lymph node ratio of 12 : 1, thus permitting the complete excision of the tumour to exclude lymph node and/or parietal involvement. A lung carcinoid was diagnosed at histology. The patient is still alive and disease-free 24 months after surgery.111 In-OCT was found to be useful for localizing the ACTH-secreting tumour and also permitted rapid non-invasive differential diagnosis between an ACTH-secreting pituitary adenoma and a malignancy causing ectopic ACTH syndrome. This study also showed the clinical usefulness of radioguided surgery in the treatment of bronchial carcinoid. European Journal of Endocrinology 137 688-690

Radioguided surgery with radiolabeled somatostatin analogs: not only in GEP-NETs

“…Recently, a new family of PET radiolabeled SSAs, synthesized through a chelation with 68 Ga, has been proposed for NET imaging. Gallium-68 may be linked to different SSAs through a chelating agent, as DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid), which is the agent of choice because of its ability to form stable complexes with different radiotracers of the metal group like 111 In, 68 Ga, 64 Cu, 90 Y and 177 Lu, with the last two radioisotopes used for radionuclide therapy.…”

“…Interestingly, while SSTRs are in vitro expressed either by NETs and SCLC, they are not expressed by NSCLC. Nevertheless, a high OCT's uptake has been observed in vivo in these tumors, due to the increased uptake at the level of activated reactive cells surrounding the neoplasm [64,65]. Being absent an OCT's uptake in normal lung, a high TBR may be obtained, although a more difficult evaluation in lesions adjacent to the diaphragm has been verified, due to scatter radiations deriving from liver and spleen.…”

A rare case of Cushing syndrome by cyclic ectopic-ACTH

“…in metastatic disease or in the case of occult tumors). Tumor-directed therapy involves an individualized approach, and can include somatostatin analogues, systemic chemotherapy, interferon-α, chemoembolization, radiofrequency ablation, and radiation therapy (21)(22)(23)(24). In the present case, surgery for tumor resection was attempted three times, but the tumor was locally invasive since diagnosis.…”

An ACTH-secreting Pituitary Adenoma Within the Sphenoid Sinus

“…Therefore, we chose fractionated external beam radiotherapy, which has been shown to achieve control of hypercortisolemia in approximately 50-60% of patients within 3-5 years of their initial pituitary surgery (7)(8)(9). In the case of ectopic ACTH syndrome, tumordirected therapy can include somatostatin analogs, systemic chemotherapy, interferon-α, chemoembolization, radiofrequency ablation, and radiation therapy (10)(11)(12)(13) …”