Variability in lutetium-177 SPECT quantification between different state-of-the-art SPECT/CT systems

Background: Quantitative SPECT imaging in targeted radionuclide therapy with lutetium-177 holds great potential for individualized treatment based on dose assessment. The establishment of dose-effect relations requires a standardized method for SPECT quantification. The purpose of this multi-center study is to evaluate quantitative accuracy and inter-system variations of different SPECT/CT systems with corresponding commercially available quantitative reconstruction algorithms. This is an important step towards a vendor-independent standard for quantitative lutetium-177 SPECT. Methods: Four state-of-the-art SPECT/CT systems were included: Discovery™ NM/CT 670Pro (GE Healthcare), Symbia Intevo™, and two Symbia™ T16 (Siemens Healthineers). Quantitative accuracy and inter-system variations were evaluated by repeatedly scanning a cylindrical phantom with 6 spherical inserts (0.5 – 113 ml). A sphere-to-background activity concentration ratio of 10:1 was used. Acquisition settings were standardized: medium energy collimator, body contour trajectory, photon energy window of 208 keV (± 10%), adjacent 20% lower scatter window, 2 × 64 projections, 128 × 128 matrix size, and 40 s projection time. Reconstructions were performed using GE Evolution with Q.Metrix™, Siemens xSPECT Quant™, Siemens Broad Quantification™ or Siemens Flash3D™ algorithms using vendor recommended settings. In addition, projection data were reconstructed using Hermes SUV SPECT™ with standardized reconstruction settings to obtain a vendor-neutral quantitative reconstruction for all systems. Volumes of interest (VOI) for the spheres were obtained by applying a 50% threshold of the sphere maximum voxel value corrected for background activity. For each sphere, the mean and maximum recovery coefficient (RCmean and RCmax) of three repeated measurements was calculated, defined as the imaged activity concentration divided by the actual activity concentration. Inter-system variations were defined as the range of RC over all systems. Re

An international multi-center investigation on the accuracy of radionuclide calibrators in nuclear medicine theragnostics

Background: Personalized molecular radiotherapy based on theragnostics requires accurate quantification of the amount of radiopharmaceutical activity administered to patients both in diagnostic and therapeutic applications. This international multi-center study aims to investigate the clinical measurement accuracy of radionuclide calibrators for 7 radionuclides used in theragnostics: 99mTc, 111In, 123I, 124I, 131I, 177Lu, and 90Y. Methods: In total, 32 radionuclide calibrators from 8 hospitals located in the Netherlands, Belgium, and Germany were tested. For each radio

Correction to: Variability in lutetium-177 SPECT quantification between different state-of-the-art SPECT/CT systems

Following publication of the original article [1], it was reported that the sphere volumes defined in the original article should be adjusted. The correct inner diameters (and volumes) of the spherical inserts were: 9.9mm (0.5 ml), 15.4mm (2.0 ml), 19.8 mm (4.0 ml), 24.8mm (8.0 ml), 31.3mm (16.0 ml) and 60mm (113 ml). Figures 3, 5 and 6 have been adjusted accordingly. The original article has been updated.</p

Correction to: [18F]mFBG PET‑CT for detection and localisation of neuroblastoma: a prospective pilot study (European Journal of Nuclear Medicine and Molecular Imaging, (2023), 50, 4, (1146-1157), 10.1007/s00259-022-06063-6)

The article [ 18F]mFBG PET‑CT for detection and localisation of neuroblastoma: a prospective pilot study, written by Atia Samim, Thomas Blom, Alex J. Poot, Albert D. Windhorst, Marta Fiocco, Nelleke Tolboom, Arthur J. A. T. Braat, Sebastiaan L. Meyer Viol, Rob van Rooij, Max M. van Noesel, Marnix G. E. H. Lam, Godelieve A. M. Tytgat, and Bart de Keizer, was originally published Online First without Open Access. After publication in volume 50, issue 4, page 1146 - 1157 the author decided to opt for Open Choice and to make the article an Open Access publication

[18F]mFBG PET-CT for detection and localisation of neuroblastoma: a prospective pilot study

Purpose: Meta-[ 18F]fluorobenzylguanidine ([ 18F]mFBG) is a positron emission tomography (PET) radiotracer that allows for fast and high-resolution imaging of tumours expressing the norepinephrine transporter. This pilot study investigates the feasibility of [ 18F]mFBG PET-CT for imaging in neuroblastoma. Methods: In a prospective, single-centre study, we recruited children with neuroblastoma, referred for meta-[ 123I]iodobenzylguanidine ([ 123I]mIBG) scanning, consisting of total body planar scintigraphy in combination with single-photon emission computed tomography-CT (SPECT-CT). Within two weeks of [ 123I]mIBG scanning, total body PET-CTs were performed at 1 h and 2 h after injection of [ 18F]mFBG (2 MBq/kg). Detected tumour localisations on scan pairs were compared. Soft tissue disease was quantified by number of lesions and skeletal disease by SIOPEN score. Results: Twenty paired [ 123I]mIBG and [ 18F]mFBG scans were performed in 14 patients (median age 4.9 years, n = 13 stage 4 disease and n = 1 stage 4S). [ 18F]mFBG injection was well tolerated and no related adverse events occurred in any of the patients. Mean scan time for [ 18F]mFBG PET-CT (9.0 min, SD 1.9) was significantly shorter than for [ 123I]mIBG scanning (84.5 min, SD 10.5), p < 0.01. Most tumour localisations were detected on the 1 h versus 2 h post-injection [ 18F]mFBG PET-CT. Compared to [ 123I]mIBG scanning, [ 18F]mFBG PET-CT detected a higher, equal, and lower number of soft tissue lesions in 40%, 55%, and 5% of scan pairs, respectively, and a higher, equal, and lower SIOPEN score in 55%, 30%, and 15% of scan pairs, respectively. On average, two more soft tissue lesions and a 6-point higher SIOPEN score were detected per patient on [ 18F]mFBG PET-CT compared to [ 123I]mIBG scanning. Conclusion: Results of this study demonstrate feasibility of [ 18F]mFBG PET-CT for neuroblastoma imaging. More neuroblastoma localisations were detected on [ 18F]mFBG PET-CT compared to [ 123I]mIBG scanning. [ 18F]mFBG PET-CT shows promise for future staging and response assessment in neuroblastoma. Trial registration: Dutch Trial Register NL8152