scholarly journals Dosimetry and optimal scan time of [18F]SiTATE-PET/CT in patients with neuroendocrine tumours

2021 ◽  
Author(s):  
Leonie Beyer ◽  
Astrid Gosewisch ◽  
Simon Lindner ◽  
Friederike Völter ◽  
Lena M. Mittlmeier ◽  
...  
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Neuroendocrine Tumours ◽  
Clinical Performance ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Tracer Uptake ◽  
Visual Evaluation ◽  
Scan Time ◽  
Pet Ct

Abstract Purpose Radiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [18F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard 68Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis. Methods Eight NET patients received a [18F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying 18F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times. Results After 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images. Conclusion [18F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to 68Ga-labelled alternatives. For clinical use of [18F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection.

scholarly journals Better way to image and manage Neuroendocrine Tumours: Role of 68Gallium DOTA-Peptide PET-CT scan

2018 ◽  
Vol 20 (2) ◽  
pp. 136
Author(s):  
Shankar Kumar Dey
Keyword(s):  
Molecular Imaging ◽  
Ct Scan ◽  
Significant Role ◽  
Neuroendocrine Tumours ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Pet Ct ◽  
Receptor Scintigraphy ◽  
Pet Ct Scan

<p>Neuroendocrine tumours (NETs) are special entity of neoplasms arising from nervous and endocrine systems and involving variety of organs. Over expression of somatostatin receptors is an unique characteristic of these tumours. This allows molecular imaging to play a significant role in evaluation of NETs using somatostatin analogues. <sup>111</sup> In Pentetreotide scintigraphy has been playing a significant role as molecular imaging of choice to locate the primary tumor, evaluate extent of disease and plan for surgical management. Recently <sup>68 </sup>Ga labelled peptides have emerged as promising PET tracers for scintigraphy of these tumours. Several recent studies have demonstrated the superiority of <sup>68</sup>Ga DOTA- Peptide PET-CT scan with a number of advantages over conventional somatostatin receptor scintigraphy.</p><p>Bangladesh J. Nuclear Med. 20(2): 136-142, July 2017</p>

Impact of flexible body surface coil and patient table on PET quantification and image quality in integrated PET/MR

2014 ◽  
Vol 53 (03) ◽  
pp. 79-87 ◽  
Author(s):  
M. Souvatzoglou ◽  
A. Martinez-Möller ◽  
M. Schwaiger ◽  
S. I. Ziegler ◽  
S. Fürst ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Image Quality ◽  
Image Noise ◽  
Ct Scanner ◽  
Patient Study ◽  
Surface Coils ◽  
Scan Time ◽  
Pet Ct ◽  
Relative Standard ◽  
Patient Table

SummaryThe surface coils of the Biograph mMR integrated PET/MR system were optimised for PET, but are otherwise unaccounted for. The patient table is still more massive than those of PET/CT devices. The goal was to assess those hardware effects on quantification, count statistics, image quality and scan time both with phantoms and in patients and to investigate their clinical relevance. Patients, material, methods: PET phantom data were acquired with and without the patient table. Image noise was expressed as relative standard deviation and compared to a state-of-the-art PET/CT scanner. Protocols of the phantom/patient study regarding the surface coils were similar. Thoraces/ab- domens of 11 patients were scanned with and without a coil (1 BP, 4 min). Mean uptake and standard deviation in a cubical VOI were derived and expressed as SUV. Results: The patient table reduced the number of true coincidences (trues) by 19% (PET/MR) and by 11% (PET/CT). The scan duration for the mMR had to be increased by approximately 30% to achieve a noise level comparable to that of the PET/CT. Decreased SUVs with coil observed in the phantom were confirmed by the patient study. By removing the coil, the mean liver SUV increased by (6 ± 2)%. With (+3 ± 14)%, the average change was similar in lesions, but exceeded 20% in almost one fifth of them. The number of trues grew by (6 ± 1)% for the patients and by 7% for the phantom. Conclusion: Due to the additional attenuation caused by MR hardware, PET scan durations would have to be increased compared to current PET/CTs to provide similar image noise levels. The effect of the coils is mostly in the order of statistical fluctuations. In tumour lesions, it is more pronounced and shows a larger variability. Therefore, coils should be included in the attenuation correction to ensure accurate quantification and thus comparability across PET/MR and PET/CT scanners and within patient populations.

scholarly journals Phantom-based image quality assessment of clinical 18F-FDG protocols in digital PET/CT and comparison to conventional PMT-based PET/CT

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Silvano Gnesin ◽  
Christine Kieffer ◽  
Konstantinos Zeimpekis ◽  
Jean-Pierre Papazyan ◽  
Renaud Guignard ◽  
...  
Keyword(s):  
Image Quality ◽  
State Of The Art ◽  
Signal To Noise Ratio ◽  
Patient Comfort ◽  
Scan Time ◽  
Pet Ct ◽  
Digital Pet ◽  
Mass Activity ◽  
Cross Calibration ◽  
Comparable Image Quality

Abstract Background We assessed and compared image quality obtained with clinical 18F-FDG whole-body oncologic PET protocols used in three different, state-of-the-art digital PET/CT and two conventional PMT-based PET/CT devices. Our goal was to evaluate an  improved trade-off between administered activity (patient dose exposure/signal-to-noise ratio) and acquisition time (patient comfort) while preserving diagnostic information achievable with the recently introduced digital detector technology compared to previous analogue PET technology. Methods We performed list-mode (LM) PET acquisitions using a NEMA/IEC NU2 phantom, with activity concentrations of 5 kBq/mL and 25 kBq/mL for the background (9.5 L) and sphere inserts, respectively. For each device, reconstructions were obtained varying the image statistics (10, 30, 60, 90, 120, 180, and 300 s from LM data) and the number of iterations (range 1 to 10) in addition to the employed local clinical protocol setup. We measured for each reconstructed dataset: the quantitative cross-calibration, the image noise on the uniform background assessed by the coefficient of variation (COV), and the recovery coefficients (RCs) evaluated in the hot spheres. Additionally, we compared the characteristic time-activity-product (TAP) that is the product of scan time per bed position × mass-activity administered (in min·MBq/kg) across datasets. Results Good system cross-calibration was obtained for all tested datasets with < 6% deviation from the expected value was observed. For all clinical protocol settings, image noise was compatible with clinical interpretation (COV < 15%). Digital PET showed an improved background signal-to-noise ratio as compared to conventional PMT-based PET. RCs were comparable between digital and PMT-based PET datasets. Compared to PMT-based PET, digital systems provided comparable image quality with lower TAP (from ~ 40% less and up to 70% less). Conclusions This study compared the achievable clinical image quality in three state-of-the-art digital PET/CT devices (from different vendors) as well as in two conventional PMT-based PET. Reported results show that a comparable image quality is achievable with a TAP reduction of ~ 40% in digital PET. This could lead to a significant reduction of the administered mass-activity and/or scan time with direct benefits in terms of dose exposure and patient comfort.

scholarly journals Clinical performance of long axial field of view PET/CT: a head-to-head intra-individual comparison of the Biograph Vision Quadra with the Biograph Vision PET/CT

2021 ◽  
Author(s):  
Ian Alberts ◽  
Jan-Niklas Hünermund ◽  
George Prenosil ◽  
Clemens Mingels ◽  
Karl Peter Bohn ◽  
...  
Keyword(s):  
Image Quality ◽  
Low Dose ◽  
Clinical Performance ◽  
Visual Image ◽  
Target Lesion ◽  
Field Of View ◽  
List Mode ◽  
Axial Field ◽  
Individual Comparison ◽  
Pet Ct

Abstract Purpose To investigate the performance of the new long axial field-of-view (LAFOV) Biograph Vision Quadra PET/CT and a standard axial field-of-view (SAFOV) Biograph Vision 600 PET/CT (both: Siemens Healthineers) system using an intra-patient comparison. Methods Forty-four patients undergoing routine oncological PET/CT were prospectively included and underwent a same-day dual-scanning protocol following a single administration of either 18F-FDG (n = 20), 18F-PSMA-1007 (n = 16) or 68Ga-DOTA-TOC (n = 8). Half the patients first received a clinically routine examination on the SAFOV (FOVaxial 26.3 cm) in continuous bed motion and then immediately afterwards on the LAFOV system (10-min acquisition in list mode, FOVaxial 106 cm); the second half underwent scanning in the reverse order. Comparisons between the LAFOV at different emulated scan times (by rebinning list mode data) and the SAFOV were made for target lesion integral activity, signal to noise (SNR), target lesion to background ratio (TBR) and visual image quality. Results Equivalent target lesion integral activity to the SAFOV acquisitions (16-min duration for a 106 cm FOV) were obtained on the LAFOV in 1.63 ± 0.19 min (mean ± standard error). Equivalent SNR was obtained by 1.82 ± 1.00 min LAFOV acquisitions. No statistically significant differences (p > 0.05) in TBR were observed even for 0.5 min LAFOV examinations. Subjective image quality rated by two physicians confirmed the 10 min LAFOV to be of the highest quality, with equivalence between the LAFOV and the SAFOV at 1.8 ± 0.85 min. By analogy, if the LAFOV scans were maintained at 10 min, proportional reductions in applied radiopharmaceutical could obtain equivalent lesion integral activity for activities under 40 MBq and equivalent doses for the PET component of <1 mSv. Conclusion Improved image quality, lesion quantification and SNR resulting from higher sensitivity were demonstrated for an LAFOV system in a head-to-head comparison under clinical conditions. The LAFOV system could deliver images of comparable quality and lesion quantification in under 2 min, compared to routine SAFOV acquisition (16 min for equivalent FOV coverage). Alternatively, the LAFOV system could allow for low-dose examination protocols. Shorter LAFOV acquisitions (0.5 min), while of lower visual quality and SNR, were of adequate quality with respect to target lesion identification, suggesting that ultra-fast or low-dose acquisitions can be acceptable in selected settings.

scholarly journals Antitumour Effects of Somatostatin Analogues in the Treatment of Neuroendocrine Tumours

2012 ◽  
Vol 08 (03) ◽  
pp. 156
Author(s):  
Diogo Assed Bastos ◽  
Brenda Gumz ◽  
Frederico Costa ◽  
◽  
◽  
...  
Keyword(s):  
Neuroendocrine Tumours ◽  
Antitumour Activity ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Antiangiogenic Activity ◽  
Tumour Shrinkage ◽  
Phosphotyrosine Phosphatases ◽  
Antitumour Effects

Neuroendocrine tumours (NETs) are rare and heterogeneous neoplasms that can present with functional syndromes due to the hypersecretion of peptides. Somatostatin analogues (SSAs) have been used since the 1980s for the treatment of neuroendocrine tumours, with the aim of controlling the symptoms of functioning tumours and improving patients’ quality of life. Data from preclinical studies offer evidence of both direct and indirect mechanisms by which SSAs can exert antitumour effects. The activation of somatostatin receptors by SSAs leads to the activation of phosphotyrosine phosphatases, which control downstream apoptotic and antiproliferation signalling pathways. Also, the suppression of secretion of several growth factors and inhibition of antiangiogenic activity by SSAs indirectly inhibits tumour cell proliferationin vitro. Previous uncontrolled studies had shown tumour shrinkage and disappearance in response to the SSA octreotide. Recent results from the randomised and placebo-controlled PROMID trial have demonstrated that octreotide has antitumour activity in patients with metastatic mid-gut NETs. This article examines recent data providing evidence of the antitumour activity of somatostatin analogues.

Antitumour Effects of Somatostatin Analogues in the Treatment of Neuroendocrine Tumours

2010 ◽  
Vol 8 (2) ◽  
pp. 94
Author(s):  
Diogo Assed Bastos ◽  
Brenda Gumz ◽  
Frederico Costa ◽  
◽  
◽  
...  
Keyword(s):  
Neuroendocrine Tumours ◽  
Antitumour Activity ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Antiangiogenic Activity ◽  
Tumour Shrinkage ◽  
Phosphotyrosine Phosphatases ◽  
Antitumour Effects

Neuroendocrine tumours (NETs) are rare and heterogeneous neoplasms that can present with functional syndromes due to the hypersecretion of peptides. Somatostatin analogues (SSAs) have been used since the 1980s for the treatment of neuroendocrine tumours, with the aim of controlling the symptoms of functioning tumours and improving patients’ quality of life. Data from preclinical studies offer evidence of both direct and indirect mechanisms by which SSAs can exert antitumour effects. The activation of somatostatin receptors by SSAs leads to the activation of phosphotyrosine phosphatases, which control downstream apoptotic and antiproliferation signalling pathways. Also, the suppression of secretion of several growth factors and inhibition of antiangiogenic activity by SSAs indirectly inhibits tumour cell proliferationin vitro. Previous uncontrolled studies had shown tumour shrinkage and disappearance in response to the SSA octreotide. Recent results from the randomised and placebo-controlled PROMID trial have demonstrated that octreotide has antitumour activity in patients with metastatic mid-gut NETs. This article examines recent data providing evidence of the antitumour activity of somatostatin analogues.

scholarly journals GEP–NETs UPDATE: Biotherapy for neuroendocrine tumours

2015 ◽  
Vol 172 (1) ◽  
pp. R31-R46 ◽  
Author(s):  
T Alonso-Gordoa ◽  
J Capdevila ◽  
E Grande
Keyword(s):  
Neuroendocrine Tumours ◽  
Symptomatic Relief ◽  
Somatostatin Receptors ◽  
Treatment Strategies ◽  
Mtor Inhibitors ◽  
Somatostatin Analogues ◽  
Antiangiogenic Agents ◽  
Tumour Control ◽  
Control Growth ◽  
Long Time

Neuroendocrine tumours (NETs) represent a less frequent and heterogeneous group of tumours, which has experienced, in recent years, a significant increase in effective therapeutic possibilities overcoming the disappointing results from chemotherapy. Initial improvements in treatment strategies came from somatostatin analogues (SSAs) that have widely demonstrated a significant improvement in symptomatic relief and tumour control growth by a complex mechanism of action over cell survival, angiogenesis and immunomodulation. Recent investigations have pointed out novel SSAs with a wider binding profile (pasireotide), chimeric molecules against somatostatin receptors and dopamine receptors and the combination with targeted agents, such as mTOR inhibitors or antiangiogenic agents. Immunotherapy is the second cornerstone in NET treatment and has been represented with interferon alpha for a long time, with a demonstrated activity on tumour and clinical response. Its less manageable adverse events have limited its usage. However, different checkpoints in immune system regulation have been effectively targeted in different solid tumours, and novel approaches are currently arising in NETs. In conclusion, biotherapy remains an active treatment strategy for initial approach in patients with NETs. Further investigation on patients' selection, molecular profiles, treatment sequence or combination and optimisation of current and novel biotherapy agents is required.

scholarly journals Recent advances in radiological and radionuclide imaging and therapy of neuroendocrine tumours

2004 ◽  
Vol 151 (1) ◽  
pp. 15-27 ◽  
Author(s):  
G Kaltsas ◽  
A Rockall ◽  
D Papadogias ◽  
R Reznek ◽  
AB Grossman
Keyword(s):  
Chromaffin Cell ◽  
Neuroendocrine Tumours ◽  
Somatostatin Receptors ◽  
Somatostatin Analogues ◽  
Therapeutic Modality ◽  
Response To Treatment ◽  
Helical Computed Tomography ◽  
Positron Emission ◽  
Octreotide Therapy ◽  
Magnetic Resonance Imaging Mri

Neuroendocrine tumours (NETs) constitute a heterogeneous group of tumours that are able to express cell membrane neuroamine uptake mechanisms and/or specific receptors, such as somatostatin receptors, which can be of great value in the localization and treatment of these tumours. Scintigraphy with (111)In-pentetreotide has become one of the most important imaging investigations in the initial identification and staging of gastro-enteropancreatic (GEP) tumours, whereas helical computed tomography (CT), magnetic resonance imaging (MRI), endoscopic and/or peri-operative ultrasonography are used for the precise localization of GEPs and in monitoring their response to treatment. Scintigraphy with (123)I-MIBG (meta-iodobenzylguanidine) is sensitive in the identification of chromaffin cell tumours, although scintigraphy with (111)In-pentetreotide may also have a role in the localization of malignant chromaffin cell tumours and medullary thyroid carcinoma; for further localization and monitoring of the response to treatment both CT and MRI are used with high diagnostic accuracy. More recently, positron emission tomography (PET) scanning is being increasingly used for the localization of NETs, particularly when other imaging modalities have failed, although its precise role and utility remain to be defined. Surgery is still the usual initial therapeutic, and only curative, modality of choice; however, the majority of NETs will require further treatment with somatostatin analogues and/or interferon; chemotherapy may be used for progressive and highly aggressive NETs, but its role has not been clearly defined. For those NETs that demonstrate uptake to a diagnostic scan with (123)I-MIBG or (111)In-octreotide, therapy with radionuclides such as (131)I-MIBG or (111)In/(90)Y-octreotide or other isotopes, presents a further evolving therapeutic modality.

scholarly journals The effect of reduced scan time on response assessment FDG-PET/CT imaging using Deauville score in patients with lymphoma

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Charlotte Hornnes ◽  
Annika Loft ◽  
Liselotte Højgaard ◽  
Flemming Littrup Andersen
Keyword(s):  
Image Quality ◽  
Hodgkin Lymphoma ◽  
Fdg Pet ◽  
Response Assessment ◽  
Acquisition Time ◽  
List Mode ◽  
Deauville Score ◽  
Scan Time ◽  
Pet Ct ◽  
Fdg Pet Ct

Abstract Purpose [18F]Fluoro-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) is used for response assessment during therapy in Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Clinicians report the scans visually using Deauville criteria. Improved performance in modern PET/CT scanners could allow for a reduction in scan time without compromising diagnostic image quality. Additionally, patient throughput can be increased with increasing cost-effectiveness. We investigated the effects of reducing scan time of response assessment FDG-PET/CT in HL and NHL patients on Deauville score (DS) and image quality. Methods Twenty patients diagnosed with HL/NHL referred to a response assessment FDG-PET/CT were included. PET scans were performed in list-mode with an acquisition time of 120 s per bed position(s/bp). From PET list-mode data images with full acquisition time of 120 s/bp and shorter acquisition times (90, 60, 45, and 30 s/bp) were reconstructed. All images were assessed by two specialists and assigned a DS. We estimated the possible savings when reducing scan time using a simplified model based on assumed values/costs for our hospital. Results There were no significant changes in the visually assessed DS when reducing scan time to 90 s/bp, 60 s/bp, 45 s/bp, and 30 s/bp. Image quality of 90 s/bp images were rated equal to 120 s/bp images. Coefficient of variance values for 120 s/bp and 90 s/bp images was significantly < 15%. The estimated annual savings to the hospital when reducing scan time was 8000-16,000 €/scanner. Conclusion Acquisition time can be reduced to 90 s/bp in response assessment FDG-PET/CT without compromising Deauville score or image quality. Reducing acquisition time can reduce costs to the clinic.

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