Peptide and pseudo-peptide.

In recent years, the introduction of theranostic twins for specific diagnosis and treatment in patients with neuroendocrine tumors became a nuclear medicine success story. 64Cu/18F labeled prostate specific membrane antigen (PSMA) for molecular imaging with PET-CT and peptide radioligand therapy with 177Lu labeled PSMA inhibitors will favorably become the next theranostic twins in nuclear medicine history. 68Ga/ 64Cu/18F PSMA PET/CT detects metastatic prostate cancer with high diagnostic sensitivity and specificity. In addition, it can be used to select patients for radioligand therapy and evaluate therapy response. 64Cu-labeled radiopharmaceuticals such as 64Cu-PSMA, and 64Cu-somatostatin analogs are promising imaging tools in the assessment of primary disease and also in the detection of disease recurrence and to evaluate therapy response. The long half-life of 64Cu allows the distribution of the tracer to PET centers as a satellite concept, who otherwise has no access to 68Ga generators.

Surgery with Radical Intent: Is There an Indication for G3 Neuroendocrine Neoplasms?

BACKGROUND: While platinum-based chemotherapy represents the standard treatment for advanced grade 3 (G3) neuroendocrine neoplasms (NENs) according to the European Neuroendocrine Tumor Society guidelines, the role of radical-intended surgery in these patients, as well as the use of adjuvant chemotherapy, are still controversial. The aim of the present work is to describe, in a retrospective series of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) G3, the overall survival (OS) rate and risk factors for death after radical surgery. Secondary aims are the description of median recurrence-free survival (RFS) and of the role of adjuvant chemotherapy. PATIENTS AND METHODS: Multicenter analysis of a series of stage I-III GEP-NEN G3 patients receiving radical surgery (R0/R1) with/without adjuvant chemotherapy was performed. RESULTS: Sixty patients from eight neuroendocrine tumor (NET) referral centers, with median follow-up of 23 months (5-187 months) were evaluated. While 28.6% of cases had NET G3, 71.4% had neuroendocrine carcinoma G3 (NEC G3). The 2-year OS rate after radical surgery was 64.5%, with a statistically significant difference in terms of Ki67 threshold (cut-off 55%, P = 0.03) and tumor differentiation (NEC G3 vs. NET G3, P = 0.03). Median RFS after radical surgery was 14 months, and 2-year RFS rate was 44.9%. Use of adjuvant chemotherapy provided no benefit in terms of either OS or RFS in this series. CONCLUSIONS: Surgery with radical intent might represent a valid option for GEP-NEN G3 patients with locoregional disease, especially with Ki67 value ≤ 55%.

Downgrading of a G3 Neuroendocrine Tumor to a G2 Tumor: Can First-Line Cytotoxic Chemotherapy Change the Tumor Biology?

The antiproliferative treatment options for neuroendocrine tumors (NET)/neuroendocrine carcinomas of the gastrointestinal tract critically depend on the proliferation rate, evaluated by immunohistochemical staining for Ki-67. According to their grading, tumors are treated with somatostatin analogs, mTOR inhibitors, or cytotoxic substances. This case illustrates downgrading of a primarily highly proliferative NET achieved by a variation of cytotoxic chemotherapy regimens, followed by a combination therapy using everolimus together with lanreotide. The latter medication might lead to a good clinical response as far as tumor growth is concerned.

The value of FDG-PET in the diagnosis of thromboangiitis obliterans--a case series.

Thromboangiitis obliterans (TAO) is an inflammatory vascular disease affecting dominantly the vessels of the extremities and is etiologically strongly associated with tobacco consumption. Different imaging techniques are generally used to exclude potential differential diagnoses. We investigated the value of (18) F-flourodeoxyglucose positron emission tomography ([(18) F]FDG-PET) in the diagnosis of TAO. All consecutive patients with diagnosed TAO between Nov 2001 and Nov 2003 at our institution who underwent [(18) F]FDG-PET in the diagnostic workup were analyzed retrospectively. Whole-body scans were conducted after a fasting period of at least 6 h and blood glucose levels lower than 180 mg/dl. The primary endpoint was defined as significantly increased vascular FDG uptake. Tracer uptake was visually determined and, in accordance with strength, divided into grades 0 to 3. In total, ten patients were statistically evaluated. The median patient age at the date of the first [(18) F]FDG-PET was 41.5 years. Repetitive FDG-PET imaging was performed in seven out of ten patients (70 %). The endpoint was objectified in one of the initial examinations (10 %) and in another one out of seven follow-up scans (14.3 %). One positive [(18) F]FDG-PET was observed in the pelvic vessels and the other in the infrapopliteal arteries. Therefore, increased tracer uptake could be observed in two examinations on two different patients (both with grade 3 tracer uptake) out of 17 conducted [(18) F]FDG-PETs in total. The [(18) F]FDG-PET was not a suitable investigative procedure for the diagnosis of TAO in the present patient cohort.

Additional lesions detected in therapeutic scans with 177Lu-DOTATATE reflect higher affinity of 177Lu-DOTATATE for somatostatin receptors.

OBJECTIVE: Peptide receptor-targeted radionuclide therapy (PRRT) of somatostatin receptor (SR)-expressing neuroendocrine tumors (NETs) has become an established therapeutic option in patients with advanced NETs. The aim of this study was to compare the lesion detection rate of (99m)Tc-EDDA/HYNIC-TOC, a newly developed tracer for NET imaging, with (177)Lu-DOTATATE used for PRRT. METHODS: 8 patients (4 women, 4 men, age range 46-76 years) with histologically proven NETs, who showed high SR loads by (99m)Tc-EDDA/HYNIC-TOC scintigraphy, were treated with (177)Lu-DOTATATE. After treatment, all patients were subjected to whole-body scintigraphy with additional low-dose single-photon emission computed tomography (SPECT-CT) of the chest and abdomen. RESULTS: All patients demonstrated (177)Lu-DOTATATE accumulation in all lesions previously detected by (99m)Tc- EDDA/HYNIC-TOC scintigraphy. Three patients showed additional lesions in the liver and lungs. CONCLUSIONS: SPECT-CT after (177)Lu-DOTATATE therapy may be helpful in detecting additional lesions not seen using (99m)Tc-EDDA/HYNIC-TOC. This could reflect the broader affinity of (177)Lu-DOTATATE for SRs compared with (99m)Tc-EDDA/HYNIC-TOC.

Insights into epiploic appendagitis.

Epiploic appendagitis is a rare cause of abdominal pain. Diagnosis of epiploic appendagitis, although infrequent, is easily made with CT or ultrasonography in experienced hands. As reported in the literature, most patients with primary epiploic appendagitis are treated conservatively without surgery, with or without anti-inflammatory drugs. A small number of patients are treated with antibiotics and some patients require surgical intervention to ensure therapeutic success. Symptoms of primary epiploic appendagitis usually resolve with or without treatment within a few days. A correct diagnosis of epiploic appendagitis with imaging procedures enables conservative and successful outpatient management of the condition and avoids unnecessary surgical intervention and associated additional health-care costs. Gastroenterologists and all medical personnel should be aware of this rare disease, which mimics many other intra-abdominal acute and subacute conditions, such as diverticulitis, cholecystitis and appendicitis. This article reviews epiploic appendagitis and includes discussion of clinical findings, pathophysiology, diagnosis and therapeutic possibilities.

99mTc-apcitide scintigraphy in patients with clinically suspected deep venous thrombosis and pulmonary embolism.

AIM: Detection of acute deep venous thrombosis (DVT) in patients presenting with clinical symptoms suggesting DVT and pulmonary embolism (PE) with (99m)Tc-apcitide, a synthetic polypeptide, binding to glycoprotein IIb/IIIa receptors expressed on activated platelets is the objective of the study. MATERIALS AND METHODS: Nineteen patients (11 males, eight females) received within 24h after admission to the hospital a mean of 841 MBq (range 667 to 1,080) (99m)Tc-apcitide i.v. followed by planar recordings 10, 60, and 120 min after injection. Images were compared to the results of compression ultrasonography and/or phlebography. Patients with clinically suspected PE underwent spiral computed tomography or lung perfusion scans. RESULTS: (99m)Tc-apcitide scintigraphy showed acute clot formation in 14 out of 16 patients where the other imaging modalities suggested DVT. Positive scintigraphic results were seen up to 17 days after the onset of clinical symptoms. In three out of three patients without any proof of DVT, (99m)Tc-apcitide scintigraphy was truly negative. Glycoprotein receptor imaging showed only one segmental PE in six patients with imaging-proven subsegmental (N = 3) or segmental PE (N = 3). CONCLUSION: (99m)Tc-apcitide scintigraphy may be an easy and promising tool for the detection of acute clot formation in patients with DVT up to 17 days after the onset of clinical symptoms with a sensitivity of 87% and a specificity of 100%. However, it failed to demonstrate PE in 83% of examined patients with proven PE.

Evaluation of conditions associated with glycated hemoglobin values below the reference range.

BACKGROUND: Evaluation of conditions associated with glycated hemoglobin (HbA1c) values below the reference range in HbA1c determinations. METHODS: Over a time period of 5 years, HbA1c results were determined with the ion-exchange high-performance liquid chromatography (HPLC) method HA-8140 Menarini. RESULTS: Of approximately 20 000 HbA1c results analyzed, 9 were below the reference range. The reason for HbA1c values below the reference range was found to be liver cirrhosis in 6 patients, anemia with hematological neoplasms in 2 patients, and elevated fetal hemoglobin > 1.5% in one patient. The silent hemoglobin (Hb) variant Hb Graz in 6 patients, Hb Sherwood Forest in 1 patient, homozygote HbS in one patient, and gross hypertriglyceridemia in one patient demonstrated no HbA1c result. CONCLUSIONS: In patients with liver cirrhosis, HbA1c measurements should be used with caution when evaluating long-term glucose control, and samples with suspected Hb variants should be analyzed by hemoglobin electrophoresis. Our study underscores the need for clinical laboratories and physicians to be aware of the limitations of their HbA1c assay methods as well as of the importance of visual inspection of ion-exchange chromatograms to detect HbA1c values below the reference range and abnormalities caused by the interference factors described here.

Complete remission of a metastatic gastrointestinal stromal tumour with the tyrosine kinase inhibitor imatinib (STI 571): effect of low dosage in an advanced tumour with exon 11 mutation.

We report a 51-year-old man with an advanced malignant metastatic gastrointestinal stromal tumour, who showed a complete response after 5 months of treatment with imatinib at a dose of 400 mg per day. An early treatment response was demonstrated in an 18fluorodeoxyglucose positron emission tomography scan after 1 month of therapy. Complete remission was documented histologically by negative serial biopsies of residual tumour nodes after 5 months of therapy. No serious side effects were seen with imatinib. A 21 bp, exon 11, in-frame mutation of the c-kit gene was found by DNA sequence analysis of tumour tissue.