Octreotide scintigraphy localizes somatostatin receptor-positive islet cell carcinomas

Tyr-3-Octreotide is a synthetic derivative of somatostatin and a somatostatin-receptor analogue. The iodine-123-labelled compound localizes somatostatin-receptor-positive tumours. In this paper two patients are reported in whom somatostatin receptors were demonstrated in vitro. In a 60-year-old female with an islet cell carcinoma of the pancreas, multiple liver metastases and previously unrecognized bone metastases in the right acetabulum could be diagnosed as the reason for a persistent hypoglycaemia. In a 60-year-old male an islet cell carcinoma of the pancreas was localized with¹²³I-Tyr-3-octreotide. The somatostatin receptors were demonstrated in vitro and the tumour was successfully treated with somatostatin. These studies demonstrate that¹²³I-Tyr-3-octreotide offers the possibility of localizing somatostatin-receptor-positive tumours and their metastases. Moreover the method makes it possible to determine the receptor status of a tumour in vivo.     

Bone scintigraphy and somatostatin receptor scintigraphy in pediatric patients with bone involvement in Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a granulomatous disease which can involve multiples sites of the body. Diagnostic imaging is of utmost importance in the management of these patients. Up to now radiographic skeletal survey and bone scintigraphy (BS) have been used to assess bone involvement (both with low specificity). Magnetic resonance imaging (MRI) and CT have been used to assess visceral involvement but with the limitation that they cannot give information about the functional status. Recently somatostatin receptor scintigraphy (SSRS) has been proposed to detect active lesions and to monitor response to treatment. The aim of this study is to assess bone and somatostatin receptor scintigraphy in the detection of bone involvement in LCH in children. Twenty scintigraphies (12 SSRS and 8 BS) were performed in seven patients (3 girls and 4 boys) aged at diagnosis: 18 month-12 years (mean age 6 years). The findings obtained in the scintigraphies were compared with clinical evolution and other imaging techniques. Bone scintigraphy detected all the LCH bone lesions, and discovered one unknown lesion. SSRS scintigraphy visualised the active lesions in 3 patients (clinical and other imaging techniques were also positive). SSRS was negative in one patient classified as disease free and another in clinical remission. SSRS detected 2 new unknown bone lesions, but could not detect LCH bone lesions confirmed in other imaging techniques in 2 patients. Somatostatin receptor and Bone scintigraphy can be used to detect active LCH bone lesions in children and can help to monitor response to treatment. Further studies with more patients are needed to confirm the diagnostic usefulness of these techniques.     

Radioiodinated somatostatin analog scintigraphy in small-cell lung cancer.

Somatostatin receptors have been characterized on biopsy specimens from small-cell lung carcinoma (SCLC) and on cultured human SCLC cells. We recently described the in vivo visualization of various somatostatin receptor-positive tumors, such as carcinoids and endocrine pancreatic tumors, after injection of 123I-Tyr-3-octreotide, a radiolabeled somatostatin analog. In the present study, this imaging procedure using 123I-Tyr-3-octreotide is reported in 11 patients with lung tumors. In five of eight patients with SCLC (63%), we were able to demonstrate tumor deposits using 123I-Tyr-3-octreotide scintigraphy. Unexpected metastases were found in two patients. In one of three patients with SCLC in whom tumor was not visualized, nonvisualization may have been caused by tumor necrosis and recent radiotherapy. In one of two patients with malignant small-cell tumors as described by Askin, the neoplasm was visualized. Like SCLC, these tumors are thought to derive from neuroendocrine cells. In one patient, a squamous-cell carcinoma and a bronchial adenoma were not visualized. We conclude that in the majority of patients with SCLC, the tumor and its metastases can be visualized using 123I-Tyr-3-octreotide scintigraphy. However, the value of this new technique in terms of specificity and sensitivity requires further studies in a larger group of patients.     

甲状腺相关眼病与生长抑素受体显像

甲状腺相关眼病是眼眶最常见的疾病之一,是一种自身免疫性疾病。目前,临床证实免疫抑制剂和眼眶局部放疗对活动期的患者有显著疗效,而对于静止期的患者基本无效。因此,对甲状腺相关眼病患者活动度评定的准确性和客观性关系到患者的治疗方案、疗效及预后,眼眶生长抑素受体显像在判断其活动度及评价治疗效果方面有重要的意义。     

Bone marrow scintigraphy in prostatic carcinomas

Bone marrow scintigrams (MS) were performed on 73 men with histologically proven prostatic carcinomas. Follow-up data were available in 24 cases. Thirty-six patients had skeletal metastases at the time of the first MS investigation. They were compared with conventional bone scintigrams (BS) as well as clinical, biological, radiological and other follow-up data obtained for the same patients. At the present stage of revision and of follow-up of our patients, MS appeared less sensitive than BS in diagnosing skeletal metastases (94% as against 100% if all abnormal MS and BS presentations are considered as diagnostic or 83% as against 86% if more restrictive analytic criteria were applied). On the other hand, MS showed slightly higher specificity (81% for MS as against 73% for BS) when all abnormal MS and BS presentations are considered as diagnostic. With more restrictive diagnostic criteria, BS remains more specific (100%) than MS (87%). Nevertheless, the likelihood of bone metastasis is low when a normal MS is found in case of dubious BS situations, but high when the MS is pathological. In 11 patients with skeletal metastasis for whom follow-up investigations were available, MS appeared better than (4 cases) or equivalent to (6 cases) BS for evaluating the responses and the ultimate evolution of the disease. Marrow scintigrams are thus a useful tool in cases of dubious BS and for evaluating the response of skeletal metastasis to treatment.     

Graves眼病眶部生长抑素受体显像研究

目的用99Tcm-奥曲肽(octreotide)SPECT眼眶显像评价Graves眼病活动度和预测免疫抑制疗效。方法Graves眼病患者39例,静脉注射925MBq99Tcmoctreotide后3h进行SPECT眼眶显像,利用感兴趣区技术,计算双侧眼眶(O)枕叶(OC)放射性比值。然后所有患者接受甲基强的松龙冲击治疗,计算治疗前和治疗1个月时的眼病指数(GOI)和临床活动度评分(CAS)。结果有效组34例,OOC比值为1.76±0.17;无效组5例,OOC比值为1.26±0.19(P<0.001)。OOC比值与治疗前CAS呈正相关(r=0.47,P<0.001),与治疗前后眼病指数差值(疗效)呈正相关(r=0.55,P<0.001)。OOC比值接受器工作特性(ROC)曲线下面积为0.971,当OOC比值取1.37时,阳性预测值为97%,阴性预测值为80%。结论OOC比值可反映Graves眼病患者眼病活动度和预测其免疫抑制疗效。     

In vivo use of a radioiodinated somatostatin analogue: dynamics, metabolism, and binding to somatostatin receptor-positive tumors in man.

Somatostatin analogues, labeled with gamma-emitting radionuclides, are of potential value in the localization of somatostatin receptor-positive tumors with gamma camera imaging. We investigated the application in man of a radioiodinated analogue of somatostatin, 123I-Tyr-3-octreotide, which has similar biologic characteristics as the native peptide. The radiopharmaceutical is cleared rapidly from the circulation (up to 85% of the dose after 10 min) mainly by the liver. Liver radioactivity is rapidly excreted into the biliary system. Until 3 hr after injection, radioactivity in the circulation is mainly in the form of 123I-Tyr-3-octreotide. Thereafter, plasma samples contain increasing proportions of free iodide. Similarly, during the first hours after injection, radioactivity in the urine exists mainly in the form of the unchanged peptide. Thereafter, a progressive increase in radioiodide excretion is observed, indicating degradation of the radiopharmaceutical in vivo. Fecal excretion of radioactivity amounts to only a few percent of the dose. The calculated median effective dose equivalent is comparable with values for applications of other 123I-radiopharmaceuticals (0.019 mSv/MBq).     

Detection of bone metastases in patients with endocrine gastroenteropancreatic tumors: bone scintigraphy compared with somatostatin receptor scintigraphy.

Scintigraphy with somatostatin analogs is a sensitive method for the staging and therapeutic management of patients with endocrine gastroenteropancreatic (GEP) tumors. The aim of this study was to compare prospectively somatostatin receptor scintigraphy (SRS) using 111n-pentetreotide with bone scintigraphy using 99mTc-hydroxymethylene diphosphonate for the detection of bone metastases. METHODS: One-hundred-forty-five patients with proven endocrine GEP tumors were investigated. Patients were classified according to the presence of bone metastases as indicated by CT, MRI or histologic data. Group I included 19 patients with confirmed bone metastases, and group II included 126 patients without bone metastases. RESULTS: In group I, SRS was positive in all 19 patients with bone metastases, and bone scintigraphy was positive in 17 patients. Bone metastases were found to occur predominantly in patients with liver metastases. In group 11, 5 patients had recent bone surgery for fracture or arthritis. SRS showed bone uptake in 4 of these patients, and bone scanning showed abnormal uptake in 5. In 7 of the remaining 121 group II patients, SRS was negative and bone scanning showed abnormal bone uptake suggesting bone metastases. The detection of bone metastases was of major prognostic value, because 42% of group 1 patients died during a 2-y follow-up. CONCLUSION: In patients with GEP tumors, the accuracy of SRS appears to be similar to that of bone scintigraphy for the detection of bone metastases.     

The scintigraphy of somatostatin receptors in the carcinoid tumor

This study aimed to evaluate the diagnostic utility of 111In-DTPA-D-Phe1-octreotide scintigraphy in the different situations that can be present when an examination is requested during the clinical course of the carcinoid tumor (CT). Materials and methods: We have performed 41 scintigraphies with 111In-octreotide (145-185 MBq) in 35 patients (19 females and 16 males) with clinically suspected or confirmed CT. The patients were classified into five groups: Group A: Indolent symptoms of CT (n=9); B: CT staging located in lung (n=4), stomach (n=2), cecum (n=1), thymus (n=1) and pancreas (n=1); C: Carcinoid syndrome (n=1); D: CT staging after surgery located in pancreas (n=1), ovary (n=1), cecum (n=1), stomach (n=1), appendix (n=1) and ileum (n=1); and E: Post-treatment follow-up (n=13), with CT located in bronchial tree (n=5), small intestine (n=3), appendix (n=2), thymus (n=1), ovary (n=1) and unknown primary tumor (n=1). Three patients of this group had one scintigraphic study before the treatment. Head and neck, thorax and abdomen images were obtained at 4 and 24 h in all of the patients and SPECT images of the abdomen (n=14), thorax (n=10), and brain (n=1) were obtained at 24 h in 25 patients. Results: Group A: In the 3 patients with a positive scintigraphy, the definitive diagnosis was meningioma, Hurtle cell's carcinoma and lung adenocarcinoma. The clinical follow-up in the six other patients, at least during one year, did not show any evidence of CT. Group B: Six of the 9 CT were detected with the scintigraphy. In 2 cases of bronchial CT, the scan showed sarcoidotic regional lymph node involvement and CT hepatic and bone metastases, respectively. Group C: The scintigraphy detected hepatic metastases from an unknown primary tumor. Group D: The scintigraphy was positive in 3 cases (hepatic or/and abdominal metastases) and was normal in the other 3. The scintigraphy was negative in one patient with peritoneal metastases. Group E: The scintigraphy was normal in 7 patients in concordance with the clinical follow-up. In 3 patients with a scintigraphy performed prior to treatment, the scintigraphy detected recurrence (thymic CT), progression of the metastatic disease (ovarian CT) and partial regression of the hepatic metastases (carcinoid syndrome). In the three other patients, the scintigraphy showed metastases located in liver in one patient and hepatic and extra-hepatic metastases in the two other patients. The sensitivity and specificity of 111In-Octreotide in the detection of the primary tumor and metastases were 72% and 84% respectively. Conclusions: The 111In-Octreotide scintigraphy has a low diagnostic utility in patients with indolent symptoms of CT. However, it is the first line of diagnosis for the staging of the CT and to evaluate the follow up after therapy.     

Clinical value of 24-hour delayed imaging in somatostatin receptor scintigraphy for meningioma.

Somatostatin receptor scintigraphy (SRS) using 111In-octreotide has proven useful in patients suspected of having meningiomas. Delayed imaging is regularly performed up to 24 h postinjection. However, this procedure is time consuming and expensive. Therefore, we investigated whether 24-h imaging may be omitted in these patients. METHODS: After clinical examination and standard MRI, 71 patients were suspected of having 92 meningioma lesions. Before surgery, all patients underwent SRS after intravenous injection of 200 MBq (5.4 mCi) 111In-octreotide. Planar whole-body images were obtained at 10 min and 1, 4 and 24 h, and SPECT was performed at 4 and 24 h. Results of SRS in all lesions were evaluated with respect to histology and time of image acquisition. RESULTS: SRS yielded 58 true-positive, 20 true-negative and 14 false-negative results, with the false-negatives all less than 5 mL (2.3+/-2.1 mL) in volume. In 52 of 58 true-positive lesions (89.7%), diagnosis could be established by 4-h imaging without further information by 24-h imaging. In 10 of the 52 lesions, SPECT was necessary to confirm planar findings. Imaging at 24 h was necessary in only 6 of 58 true-positive lesions (10.3%): 3 patients who had intracranial relapse of meningioma (volume < 5 mL) and 3 who had spinal meningioma. Thus, a diagnosis of intracranial meningioma could be established in 52 of 55 lesions (95%) using a 4-h imaging protocol. CONCLUSION: With a 4-h acquisition protocol that includes SPECT imaging, SRS yields sufficient information in patients suspected of having intracranial meningiomas. Delayed imaging at 24 h is recommended only for patients who have small meningiomas (volume < 5 mL), spinal localizations or negative SRS at 4 h.