Dosimetric implications of kidney anatomical volume changes in Lu-DOTATATE therapy.

Introduction: This study aims to evaluate the use of CT-based whole kidney parenchyma (WKP) segmentation in Lu-DOTATATE dosimetry. Specifically, it investigates whether WKP volumes change during treatment and evaluates the accuracy of applying a single delineated WKP volume for dosimetry. Furthermore, it aims to determine the cause of WKP volume changes-whether caused by radiation or amino acid infusion-by comparing them with spleen volume changes as a marker for radiation-induced alterations.

Evaluation of reconstruction methods and image noise levels concerning visual assessment of simulated liver lesions in In-octreotide SPECT imaging.

Background: Early cancer detection is crucial for patients' survival. The image quality in In-octreotide SPECT imaging could be improved by using Monte Carlo (MC)-based reconstruction. The aim of this observational study was to determine the detection rate of simulated liver lesions for MC-based ordered subset expectation maximization (OSEM) reconstruction compared to conventional attenuation-corrected OSEM reconstruction.

ACTIVITY CONCENTRATION ESTIMATION IN AUTOMATED KIDNEY SEGMENTATION BASED ON CONVOLUTION NEURAL NETWORK METHOD FOR 177LU-SPECT/CT KIDNEY DOSIMETRY.

For 177Lu-DOTATATE treatments, dosimetry based on manual kidney segmentation from computed tomography (CT) is accurate but time consuming and might be affected by misregistration between CT and SPECT images. This study develops a convolution neural network (CNN) for automated kidney segmentation that accurately aligns CT segmented volume of interest (VOI) to the kidneys in SPECT images. The CNN was trained with SPECT/CT images performed over the abdominal area of 137 patients treated with 177Lu-DOTATATE.

EVALUATION OF THE SPATIAL RESOLUTION IN MONTE CARLO-BASED SPECT/CT RECONSTRUCTION OF 111IN-OCTREOTIDE IMAGES.

The purpose was to evaluate the spatial resolution in 111In-octreotide single-photom emission computed tomography (SPECT)/computed tomography (CT) imaging following reconstructions with three different ordered subset expectation maximizations (OSEM) reconstruction algorithms; attenuation corrected (AC) OSEM, AC OSEM with resolution recovery (ACRR OSEM) and Monte Carlo-based OSEM reconstruction (MC OSEM). SPECT/CT imaging of a triple line phantom containing 111In in air and water was performed. The spatial resolution, represented by the full width at half maximum (FWHM) of a line profile, was determined for each line, for X and Y direction and for all reconstructions.

Incidental cardiac findings on somatostatin receptor PET/CT: What do they indicate and are they of clinical relevance?

We present the case of a 47-year-old man with a history of recurrent episodes of frontal headache, fever, and chest discomfort as well as longstanding, difficult to treat arterial hypertension. Clinical work-up revealed the unexpected finding of an underlying pheochromocytoma as well as recent "silent" myocardial infarction. Our case highlights the importance of paying attention to incidental cardiac findings on somatostatin receptor positron emission tomography/computed tomography, as routinely performed in patients with clinically suspected neuroendocrine tumors.

Deep-Learning Generation of Synthetic Intermediate Projections Improves Lu SPECT Images Reconstructed with Sparsely Acquired Projections.

The aims of this study were to decrease the Lu-SPECT acquisition time by reducing the number of projections and to circumvent image degradation by adding deep-learning-generated synthesized projections. We constructed a deep convolutional U-net-shaped neural network for generation of synthetic intermediate projections (CUSIPs). The number of SPECT investigations was 352 for training, 37 for validation, and 15 for testing.

Bone Marrow Absorbed Doses and Correlations with Hematologic Response During Lu-DOTATATE Treatments Are Influenced by Image-Based Dosimetry Method and Presence of Skeletal Metastases.

This study aimed to compare different image-based methods for bone marrow dosimetry and study the dose-response relationship during treatment with Lu-DOTATATE in patients with and without skeletal metastases. This study included 46 patients with advanced neuroendocrine tumors treated with at least 2 fractions of Lu-DOTATATE at Sahlgrenska University Hospital. High- and low-uptake compartments were automatically outlined in planar images collected at 2, 24, 48, and 168 h after injection.

18F-FDG PET/CT in the diagnosis of prosthetic valve endocarditis.

Recent studies have shown promising results using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the diagnosis of prosthetic valve endocarditis (PVE). However, previous studies did not include negative controls. The aim of this study was to compare (18)F-FDG-uptake around prosthetic aortic valves in patients with and without PVE and to determine the diagnostic performance of (18)F-FDG PET/CT in the diagnosis of PVE.

Neuroendocrine tumours: the role of imaging for diagnosis and therapy.

In patients with neuroendocrine tumours (NETs), a combination of morphological imaging and nuclear medicine techniques is mandatory for primary tumour visualization, staging and evaluation of somatostatin receptor status. CT and MRI are well-suited for discerning small lesions that might escape detection by single photon emission tomography (SPECT) or PET, as well as for assessing the local invasiveness of the tumour or the response to therapy. Somatostatin receptor imaging, by (111)In-pentetreotide scintigraphy or PET with (68)Ga-labelled somatostatin analogues, frequently identifies additional lesions that are not visible on CT or MRI scans.

Unnecessary surgery for acute abdomen secondary to angiotensin-converting enzyme inhibitor use.

Acute abdominal pain is the reason for 5% to 10% of all emergency department visits. In 1 in every 9 patients, operated on for an acute abdomen, laparotomy is negative. In a minority of patients, the acute abdomen is caused by side effects of medication.

Quality of life in 265 patients with gastroenteropancreatic or bronchial neuroendocrine tumors treated with [177Lu-DOTA0,Tyr3]octreotate.

Unlabelled: Quality of life (QOL) is an important outcome in cancer therapy. In this study, we investigated the QOL and symptoms after [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-octreotate) therapy in patients with inoperable or metastasized gastroenteropancreatic or bronchial neuroendocrine tumors (NETs).

Methods: Two hundred sixty-five Dutch patients completed the QOL questionnaire of the European Organization for the Research and Treatment of Cancer after being treated for NETs.

Salvage therapy with (177)Lu-octreotate in patients with bronchial and gastroenteropancreatic neuroendocrine tumors.

Unlabelled: Regular therapy with the radiolabeled somatostatin analog (177)Lu-octreotate (22.2-29.6 GBq) in patients with gastroenteropancreatic or bronchial neuroendocrine tumors results in tumor remission in 46% of patients, including minor response.

Peptide receptor radionuclide therapy in patients with gastroenteropancreatic neuroendocrine tumors.

Somatostatin receptor imaging with [(111)In-DTPA(0))octreotide has proven its role in the diagnosis and staging of gastroenteropancreatic neuroendocrine tumors. Treatment with radiolabeled somatostatin analogues is a promising new tool in the management of patients with inoperable or metastasized, well-differentiated neuroendocrine tumors. Symptomatic improvement may occur with all (111)In, (90)Y, or (177)Lu-labeled somatostatin analogues that have been used for peptide receptor radionuclide therapy.

Somatostatin-receptor-based imaging and therapy of gastroenteropancreatic neuroendocrine tumors.

Somatostatin receptor imaging (SRI) with [(111)In-DTPA(0)]octreotide has proven its role in the diagnosis and staging of gastroenteropancreatic neuroendocrine tumors (GEPNETs). Newer radiolabeled somatostatin analogs which can be used in positron emission tomography (PET) imaging, and which have a higher affinity for the somatostatin receptor, especially receptor subtype-2, have been developed. It would be desirable, however, if one radiolabeled analog became the new standard for PET imaging, because the current application of a multitude of analogs implies a fragmented knowledge on the interpretation of the images that are obtained in clinical practice.

Peptide-receptor radionuclide therapy for endocrine tumors.

Peptide-receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs is a promising option for the treatment of somatostatin-receptor-positive endocrine tumors. Treatment with somatostatin analogs labeled with (111)In, (90)Y or (177)Lu can result in symptomatic improvement, although tumor remission is seldom achieved with (111)In-labeled analogs. In this Review, the findings of several studies on the use of PRRT for endocrine tumors are evaluated.

Treatment with the radiolabeled somatostatin analog [177 Lu-DOTA 0,Tyr3]octreotate: toxicity, efficacy, and survival.

Purpose: Despite the fact that most gastroenteropancreatic neuroendocrine tumors (GEPNETs) are slow-growing, median overall survival (OS) in patients with liver metastases is 2 to 4 years. In metastatic disease, cytoreductive therapeutic options are limited. A relatively new therapy is peptide receptor radionuclide therapy with the radiolabeled somatostatin analog [(177)Lu-DOTA(0),Tyr(3)]octreotate.

Hormonal crises following receptor radionuclide therapy with the radiolabeled somatostatin analogue [177Lu-DOTA0,Tyr3]octreotate.

Introduction: Receptor radionuclide therapy is a promising treatment modality for patients with neuroendocrine tumors for whom alternative treatments are limited. The aim of this study was to investigate the incidence of hormonal crises after therapy with the radiolabeled somatostatin analogue [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-octreotate).

Materials And Methods: All (177)Lu-octreotate treatments between January 2000 and January 2007 were investigated.

Report on short-term side effects of treatments with 177Lu-octreotate in combination with capecitabine in seven patients with gastroenteropancreatic neuroendocrine tumours.

Purpose: Treatment with the radiolabelled somatostatin analogue (177)Lu-octreotate results in tumour remission in 47% of patients with gastroenteropancreatic neuroendocrine tumours. Adding capecitabine to (177)Lu-octreotate, as a radio-sensitiser, may enhance these anti-tumour effects. We now present the short-term toxicity profile of this novel combination.

Peptide Receptor Radionuclide Therapy with radiolabelled somatostatin analogues in patients with somatostatin receptor positive tumours.

Peptide Receptor Radionuclide Therapy (PRRT) with radiolabelled somatostatin analogues is a promising treatment option for patients with inoperable or metastasised neuroendocrine tumours. Symptomatic improvement may occur with all of the various (111)In, (90)Y, or (177)Lu-labelled somatostatin analogues that have been used. Since tumour size reduction was seldom achieved with (111)Indium labelled somatostatin analogues, radiolabelled somatostatin analogues with beta-emitting isotopes like (90)Y and (177)Lu were developed.

Peptide receptor radionuclide therapy with 177Lu-octreotate in patients with foregut carcinoid tumours of bronchial, gastric and thymic origin.

Purpose: Foregut carcinoid tumours have a different embryological origin than other gastroenteropancreatic neuroendocrine tumours (GEP NETs). In the total group of GEP NETs (n = 131), treatment with (177)Lu-octreotate resulted in tumour remission in 47% of patients, with a median time to progression (TTP) of >36 months. As patients with foregut carcinoids may respond differently, we here present the effects of this treatment in a subgroup of patients with foregut carcinoids of bronchial, gastric or thymic origin.

Effects of therapy with [177Lu-DOTA0, Tyr3]octreotate in patients with paraganglioma, meningioma, small cell lung carcinoma, and melanoma.

Unlabelled: Therapy using the radiolabeled somatostatin analog [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate) (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) has been used primarily in gastroenteropancreatic neuroendocrine tumors. Here we present the effects of this therapy in a small number of patients with metastasized or inoperable paragangliomas, meningiomas, small cell lung carcinomas (SCLCs), and melanomas.

Methods: Twelve patients with paraganglioma, 5 with meningioma, 3 with SCLC, and 2 with eye melanoma were treated.