scholarly journals 68Ga-DOTATOC PET/CT-Based Radiomic Analysis and PRRT Outcome: A Preliminary Evaluation Based on an Exploratory Radiomic Analysis on Two Patients

2021 ◽  
Vol 7 ◽  
Author(s):  
Virginia Liberini ◽  
Osvaldo Rampado ◽  
Elena Gallio ◽  
Bruno De Santi ◽  
Francesco Ceci ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Somatostatin Receptor ◽  
Principal Component ◽  
Receptor Expression ◽  
Whole Body ◽  
Poor Correlation ◽  
Preliminary Evaluation ◽  
Whitney Test ◽  
Mann Whitney Test ◽  
Pet Ct

Aim: This work aims to evaluate whether the radiomic features extracted by 68Ga-DOTATOC-PET/CT of two patients are associated with the response to peptide receptor radionuclide therapy (PRRT) in patients affected by neuroendocrine tumor (NET).Methods: This is a pilot report in two NET patients who experienced a discordant response to PRRT (responder vs. non-responder) according to RECIST1.1. The patients presented with liver metastasis from the rectum and pancreas G3-NET, respectively. Whole-body total-lesion somatostatin receptor-expression (TLSREwb-50) and somatostatin receptor-expressing tumor volume (SRETV wb-50) were obtained in pre- and post-PRRT PET/CT. Radiomic analysis was performed, extracting 38 radiomic features (RFs) from the patients' lesions. The Mann–Whitney test was used to compare RFs in the responder patient vs. the non-responder patient. Pearson correlation and principal component analysis (PCA) were used to evaluate the correlation and independence of the different RFs.Results: TLSREwb-50 and SRETVwb-50 modifications correlate with RECIST1.1 response. A total of 28 RFs extracted on pre-therapy PET/CT showed significant differences between the two patients in the Mann–Whitney test (p < 0.05). A total of seven second-order features, with poor correlation with SUVmax and PET volume, were identified by the Pearson correlation matrix. Finally, the first two PCA principal components explain 83.8% of total variance.Conclusion: TLSREwb-50 and SRETVwb-50 are parameters that might be used to predict and to assess the PET response to PRRT. RFs might have a role in defining inter-patient heterogeneity and in the prediction of therapy response. It is important to implement future studies with larger and more homogeneous patient populations to confirm the efficacy of these biomarkers.

scholarly journals NIMG-30. PET IMAGING OF ANDROGEN RECEPTOR EXPRESSION IN PATIENTS WITH GBM USING [18F]-FDHT

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii154-ii154
Author(s):  
Anat Mordechai ◽  
Ofer Shamni ◽  
Nomi Zalcman ◽  
Samuel Moscovici ◽  
Alexandre Chicheportiche ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Protein Expression ◽  
Pearson Correlation ◽  
Receptor Expression ◽  
Whole Body ◽  
Normal Brain ◽  
Poor Overall Survival ◽  
Reference Tissue ◽  
Pet Ct ◽  
Tumor Accumulation

Abstract BACKGROUND GBM is associated with poor overall survival partly due to lack of effective treatment. Recently we showed that androgen receptor (AR) protein is overexpressed in 56% of GBM specimens and that AR antagonists induced dose-dependent death in several glioblastoma cell lines. Treatment of mice implanted with human GBM with AR antagonists significantly reduced the growth of the tumor and prolonged the lifespan of the mice. 18f-fluorine-radiolabeled Dihidrotestosteron (DHT), a natural ligand of AR, [16β-18F-fluoro-5α-dihydrotestosterone ([18F]-FDHT)] is one of the PET tracers used to detect AR expression in metastatic prostate cancer. The aim of this study was to identify AR-expressing GBM tumors in real time using PET-CT scan with [18F]-FDHT. MATERIALS AND METHODS Twelve patients with GBM underwent a dynamic (first 30 min) and whole body static (later 60-80 min) [18F]-FDHT PET/CT (296-370 MBq) scans 2-4 days prior to the surgery or biopsy. Protein was extracted from the tumor and subjected to western blot analysis. AR Protein fold change of each tumor sample was calculated by densitometry analysis compared with that of normal brain, following normalization to GAPDH. RESULTS At ~60 min after injection, 6 of the 12 patients showed significantly higher tumor accumulation of [18F]-FDHT, compared to reference tissue (SUV/Control)mean: 1.33-2.63 fold, (SUV/control)max: 1.4-3.43 fold. The patient who had higher tumor accumulation of [18F]-FDHT, demonstrated also high (1.6-2.27 fold/normal brain) AR protein expression within the tumor. Pearson-correlation-coefficient analysis for the (SUV/Control)mean at ~60 min after the injection versus AR protein expression, was positive and significant (R=0.841;p=0.0024). CONCLUSION This study demonstrated for the first time that [18F]-FDHT PET can identify AR-positive-GBM-tumors (with sensitivity and specificity at 100%) and may therefore be a powerful tool to select patients eligible for treatment with AR antagonists. It could possibly be employed also to monitor treatment response and/or progression during the course of therapy.

scholarly journals Effect of Peptide Receptor Radionuclide Therapy on Somatostatin Receptor Status and Glucose Metabolism in Neuroendocrine Tumors: Intraindividual Comparison of Ga-68 DOTANOC PET/CT and F-18 FDG PET/CT

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Sowon Oh ◽  
Vikas Prasad ◽  
Dong Soo Lee ◽  
R. P. Baum
Keyword(s):  
Glucose Metabolism ◽  
Neuroendocrine Tumors ◽  
Fdg Pet ◽  
Radionuclide Therapy ◽  
Somatostatin Receptor ◽  
Peptide Receptor Radionuclide Therapy ◽  
Receptor Expression ◽  
Peptide Receptor ◽  
Pet Ct ◽  
Fdg Pet Ct

The heterogeneous nature of the neuroendocrine tumors (NET) makes it challenging to find one uniformly applicable management protocol which is especially true for diagnosis. The discovery of the overexpression of somatostatin receptors (SMS-R) on neuroendocrine tumor cells lead to the generalized and rapid acceptance of radiolabeled somatostatin receptor analogs for staging and restaging of NET as well as for Peptide Receptor Radionuclide Therapy (PRRNT) using Y-90 and Lu-177 DOTATATE/DOTATOC. In this present work we tried to look in to the effect of PRRNT on the glucose metabolism assessed by F-18 FDG PET/CT and SMS-R density assessed by Ga-68 DOTANOC PET/CT. We observed a complex relationship between the somatostatin receptor expression and glucose metabolism with only 56% (77/138) of the lesions showing match, while the others show mismatch between the receptor status and metabolism. The match between receptor expression and glucose metabolism increases with the grade of NET. In grade 3 NET, there is a concurrence between the changes in glucose metabolism and somatostatin receptor expression. PRRNT was found to be more effective in lesions with higher receptor expression.

scholarly journals Tc-99m HYNIC-TOC scintigraphy in dedifferentiated thyroid cancer

2019 ◽  
Vol 12 (4) ◽  
pp. e227910
Author(s):  
Kanhaiyalal Agrawal ◽  
P Sai Sradha Patro ◽  
C Preetam
Keyword(s):  
Thyroid Cancer ◽  
Single Photon ◽  
Somatostatin Receptor ◽  
Photon Emission ◽  
Peptide Receptor Radionuclide Therapy ◽  
Ct Imaging ◽  
Whole Body ◽  
Emission Computed Tomography ◽  
Serum Thyroglobulin ◽  
Pet Ct

There is literature evidence showing utility of somatostatin receptor (SSTR) positron emission tomography-CT (PET-CT) imaging in differentiated thyroid cancer with Thyroglobulin Elevated and Negative Iodine Scan (TENIS). These patients are less benefited with I-131 therapy and surgery remains only curable option if disease could be localised. If surgery is not feasible, other therapeutic options are not promising. However, if these patients show strongly positive SSTR imaging, then possibility of peptide receptor radionuclide therapy may be explored. As SSTR PET-CT imaging is expensive and not widely available, Technetium-99m (Tc-99m) hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC), which is a Single photon emission computed tomography (SPECT) tracer, can be used. We are documenting a case of raised serum thyroglobulin antibody and negative I-131 whole body scan with disease recurrence localised on Tc-99m HYNIC-TOC scan.

Radiation exposure of patients during 68Ga-DOTATOC PET/CT examinations

2009 ◽  
Vol 48 (05) ◽  
pp. 201-207 ◽  
Author(s):  
K. Zöphel ◽  
R. Freudenberg ◽  
L. Oehme ◽  
M. Andreeff ◽  
G. Wunderlich ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Radiation Exposure ◽  
Somatostatin Receptor ◽  
Blood Pool ◽  
Biological Data ◽  
Whole Body ◽  
Physiological Uptake ◽  
Standardized Uptake Values ◽  
Pet Ct ◽  
Routine Clinical Setting

Summary Aim: Investigation of the biodistribution and calculation of dosimetry of Ga-68-DOTATOCfor patients imaged in the routine clinical setting for diagnosis or exclusion of neuroendocrine tumours. Patients, methods: Dynamic PET/CT-imaging (Biograph 16) was performed over 20 min in 14 patients (8 men, 6 women) after injection of (112 ± 22) MBq 68Ga-DOTATOC followed by whole body 3D-acquisition (8 bed positions, 3 or 4 min each) 30 min p.i. and 120 min p.i. Urinary tracer elimination was measured and blood activity was derived non-invasively from the blood pool of the heart. The relevant organs for dosimetry were spleen, kidneys, liver, adrenals, urinary bladder and pituitary gland. Dosimetry was performed using OLINDA/ EXM 1.0 software and specific organ uptake was expressed as standardized uptake values (SUVs). Results: Rapid physiological uptake of the radiotracer could be demonstrated in liver, spleen and kidneys, adrenals and pituitary gland (mean SUVs were 6, 20, 16, 10, and 4, respectively). Radiotracer elimination was exclusively via urine (16% of injected dose within 2h); no redistribution could be observed. The spleen and the kidneys received the highest radiation exposure (0.24 mSv/MBq, 0.22 mSv/MBq resp.), mean effective dose yielded 0.023 mSv/MBq. Conclusion: 68Ga-DOTATOC is used extensively for diagnosis of somatostatin receptor positive tumours because it has several advantages over the 111In-labelled ligand. The derived dosimetric values are lower than first approximations from the biological data of OctreoScan. The use of CT for transmission correction of the PET data delivers radiation exposure up to 1 mSv (low dose).

scholarly journals TIO Associated with Hyperparathyroidism: A Rarity, a Rule, or a Novel HPT-PMT Syndrome—A Case Study with Literature Review

2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Michael Salim ◽  
Mohannad Samy Behairy ◽  
Elena Barengolts
Keyword(s):  
Literature Review ◽  
Somatostatin Receptor ◽  
Delayed Diagnosis ◽  
Whole Body ◽  
Mesenchymal Tumors ◽  
Pet Ct ◽  
Patient Reported ◽  
Minimal Improvement ◽  
Biochemical Evaluation

Objective. Association of primary hyperparathyroidism (pHPT) with phosphaturic mesenchymal tumors (PMT) is rarely reported. This report entertains the hypothesis of the causal association of HPT with tumor-induced osteomalacia (TIO) and of the existence of HPT-PMT syndrome. Case Presentation. A 49-year-old man presented with fragility rib fractures, generalized bone pain, and muscle weakness worsening over the past 3 years. Initial tests demonstrated hypophosphatemia and high PTH. The diagnosis of pHPT was entertained, but parathyroid scan was negative. During a 2-year follow-up, the patient reported minimal improvement of symptoms after intermittent treatment with calcitriol and phosphate. Biochemical evaluation showed persistent hypophosphatemia with renal phosphate wasting, elevated FGF23, and osteopenia on DXA scan. TIO was suspected. Multiple MRIs and whole-body FDG-PET scans were inconclusive. The patient subsequently underwent 68Ga-DOTATATE PET-CT, which revealed a somatostatin receptor-positive lesion in the lung. The resected mass was confirmed as PMT. The patient had dramatically improved symptoms, normal phosphate, calcium, and FGF23. During follow-up over 3 years postsurgery, the patient had slowly rising calcium and persistently elevated PTH. Conclusion. The debate whether the patient had pHPT or tertiary HPT prompted literature review showing that aberrant genes including FGFR1, FGF1, fibronectin 1, and Klotho were mechanistically involved in the HPT-PMT association. This case highlights the pitfalls contributing to delayed diagnosis and treatment of TIO and hypothesizes the association between pHPT and PMT.

scholarly journals 68Ga-DOTATATE PET in Pediatric Paraganglioma / Pheochromocytoma: A Case-series Highlighting the Role of Functional Imaging

2021 ◽  
Author(s):  
Aleksandra Augustynowicz ◽  
Neha Kwatra ◽  
Laura Drubach ◽  
Christopher Weldon ◽  
Katherine Janeway ◽  
...  
Keyword(s):  
Functional Imaging ◽  
Imaging Techniques ◽  
Somatostatin Receptor ◽  
Case Series ◽  
Response Assessment ◽  
Receptor Expression ◽  
Imaging Modalities ◽  
Nuclear Medicine Imaging ◽  
Decision Algorithm ◽  
Pet Ct

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors in childhood. Cancer predisposition syndromes (CPS) are increasingly recognized as the underlying cause for a number of pediatric malignancies and up to 40% of PPGL are currently thought to be associated with a hereditary predisposition1,2. With the increasingly widespread availability of functional molecular imaging techniques, nuclear medicine imaging modalities such as 18F-FDG-PET/CT, 123I-MIBG SPECT/CT, and 68Ga-DOTATATE PET/CT now play an essential role in the staging, response assessment and determination of suitability for targeted radiotherapy in patients with PPGL. Each of these imaging modalities targets a different cellular characteristic, such as glucose metabolism (FDG), norepinephrine transporter expression (MIBG), or somatostatin receptor expression (DOTATATE), and therefore can be complementary to anatomic imaging and to each other. Given the recent FDA approval3 and increasing use of 68Ga-DOTATATE for imaging in children4, the purpose of this article is to use a case-based approach to highlight both the advantages and limitations of DOTATATE imaging as it compares to current radiologic imaging techniques in the staging and response assessment of pediatric PPGL, and to offer a decision algorithm for the use of functional imaging that can be applied to PPGL, as well as other neuroendocrine malignancies.

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