Clinical usefulness of fluoro-2-deoxy-D-glucose PET in a case with multiple bone metastases of carcinoid tumor after ten years

Increased carbohydrate antigen 19-9 expression in a thymic neuroendocrine tumor

Here, we report a case of carbohydrate antigen (CA) 19‐9‐producing mediastinal neuroendocrine tumor (NET) (atypical carcinoid). A 54‐year‐old woman with no specific relevant medical history was referred to our hospital because of increased CA19‐9 (95.3 U/ml) detected on health screening. Chest computed tomography (CT) revealed an anterior mediastinal mass without localized lymphadenopathy. Thoracic surgery was performed and the histopathological diagnosis was thymic CA19‐9‐positive NET. The patient developed mediastinal lymph node metastasis at 1 year (CA19‐9: 413 U/ml) and multiple bone metastases 4 years (CA19‐9: 2303 U/ml) after surgery. Increased CA19‐9 levels paralleled the clinical courses of relapse. To our knowledge, this is the first report of CA19‐9‐producing thymic NET.

Spinal Metastasis Resulting from Atypical Thymic Carcinoid: A Case Report

BACKGROUND

Thymic carcinoid with spinal metastasis is an extremely rare entity. Clinically, the tumor presents either by its endocrine manifestations or by mechanical compression of surrounding structures. However, no previously published case studies have reported neck pain and neurologic deficit in the initial presentation of an atypical thymic carcinoid.

CASE DESCRIPTION

A 56-year-old man, a nonsmoker, presented with a 12-month history of intermittent neck pain and a 1-month history of progressive numbness and weakness of the right upper limb. Cervical MRI showed multiple abnormal signals and C2 soft-tissue mass intruding into the vertebral canal. Cervical CT scan showed multiple bone lesions. The diagnosis of thymic carcinoid was obtained by preoperative lymph node biopsy. The patient underwent cervical laminectomy and occipitocervical fixation. Significant alleviation of pain and neurologic improvement were achieved. The postoperative pathological examination confirmed the diagnosis of thymic carcinoid.

CONCLUSIONS

Neck pain and neurologic deficit could be the first presentation of thymic carcinoid with spinal metastasis. Palliative surgery is an effective method to improve quality of life in patients with thymic carcinoid with spinal metastasis.

Estimation of activity of administered 18F-fluorodeoxyglucose by measurement of the dose equivalent rate on the right temporal region of the head

Background

Positron emission tomography (PET) with ¹⁸F-fluorodeoxyglucose (FDG) is now a routine procedure for the management of cancer patients. Intravenous administration of FDG is sometimes halted due to troubles. In such cases, estimations of the FDG dosage injected prior to halting administration may be helpful. We have established a method of estimating the activity of FDG to patients on the basis of the dose equivalent rate on the surface of the right temporal region of the head. The correlation of actual administered dosage with independent variables, such as the dose equivalent rate on the right temporal region of the head, age, sex, and body weight, was analyzed using multiple regression analysis to obtain linear, quadratic, and cubic regression equations.

Results

When entering independent variables, the cubic regression equation could be used to estimate an administered dosage with an accuracy of ±10 % for 62 % of all patients and ±20 % for 90 % of all patients.

Conclusions

We conclude that this method is useful for estimating the administered dosage from the dose equivalent rate on the temporal region of the head.

18F-fluorodihydroxyphenylalanine vs other radiopharmaceuticals for imaging neuroendocrine tumours according to their type

6-Fluoro-(¹⁸F)-L-3,4-dihydroxyphenylalanine (FDOPA) is an amino acid analogue for positron emission tomography (PET) imaging which has been registered since 2006 in several European Union (EU) countries and by several pharmaceutical firms. Neuroendocrine tumour (NET) imaging is part of its registered indications. NET functional imaging is a very competitive niche, competitors of FDOPA being two well-established radiopharmaceuticals for scintigraphy, ¹²³I-metaiodobenzylguanidine (MIBG) and ¹¹¹In-pentetreotide, and even more radiopharmaceuticals for PET, including fluorodeoxyglucose (FDG) and somatostatin analogues. Nevertheless, there is no universal single photon emission computed tomography (SPECT) or PET tracer for NET imaging, at least for the moment. FDOPA, as the other PET tracers, is superior in diagnostic performance in a limited number of precise NET types which are currently medullary thyroid cancer, catecholamine-producing tumours with a low aggressiveness and well-differentiated carcinoid tumours of the midgut, and in cases of congenital hyperinsulinism. This article reports on diagnostic performance and impact on management of FDOPA according to the NET type, emphasising the results of comparative studies with other radiopharmaceuticals. By pooling the results of the published studies with a defined standard of truth, patient-based sensitivity to detect recurrent medullary thyroid cancer was 70 % [95 % confidence interval (CI) 62.1–77.6] for FDOPA vs 44 % (95 % CI 35–53.4) for FDG; patient-based sensitivity to detect phaeochromocytoma/paraganglioma was 94 % (95 % CI 91.4–97.1) for FDOPA vs 69 % (95 % CI 60.2–77.1) for ¹²³I-MIBG; and patient-based sensitivity to detect midgut NET was 89 % (95 % CI 80.3–95.3) for FDOPA vs 80 % (95 % CI 69.2–88.4) for somatostatin receptor scintigraphy with a larger gap in lesion-based sensitivity (97 vs 49 %). Previously unpublished FDOPA results from our team are reported in some rare NET, such as small cell prostate cancer, or in emerging indications, such as metastatic NET of unknown primary (CUP-NET) or adrenocorticotropic hormone (ACTH) ectopic production. An evidence-based strategy in NET functional imaging is as yet affected by a low number of comparative studies. Then the suggested diagnostic trees, being a consequence of the analysis of present data, could be modified, for some indications, by a wider experience mainly involving face-to-face studies comparing FDOPA and ⁶⁸Ga-labelled peptides.

Skeletal metastasis of carcinoid tumors: Two case reports and review of the literature

Carcinoid tumors are neuroendocrine neoplasms derived from enterochromaffin cells. Skeletal metastases from carcinoid tumors are considered to be extremely rare. In this study, we present two cases of carcinoid tumors that metastasized to the bone. Furthermore, we review 50 published case reports and reveal the features of skeletal metastasis of carcinoid tumors. The first case involved a 59-year-old man with a history of multiple metastases of a lung carcinoid tumor. The patient complained of back pain and numbness in the lower limbs. Magnetic resonance imaging revealed metastases in the thoracic spine. A spinal decompression was performed and the symptoms were resolved. The second case involved a 74-year-old man had been diagnosed with a lung carcinoid tumor 15 years previously and complained of left thigh pain. A radiograph showed osteolytic lesions in the shaft of the left femur. We repaired the femur using an intramedullary nail following curettage of the tumor. A radiograph of the femur revealed a callus on the pathological fracture. The patient was able to walk using a crutch 3 months after surgery. We reviewed 50 cases that described skeletal metastasis from carcinoid tumors. The average age of the patients was 54.9 years and 33 patients (66%) were male. The most common site of skeletal metastasis was the spine. We also investigated the survival rate of patients who developed skeletal metastasis from carcinoid tumors. The findings showed that survival of patients who developed osteolytic skeletal metastasis was worse than that of patients who developed osteosclerotic skeletal metastasis.