Background: The American Thyroid Association (ATA), the European Association of Nuclear Medicine, the European Thyroid Association, and the Society of Nuclear Medicine and Molecular Imaging have established an intersocietal working group to address the current controversies and evolving concepts in thyroid cancer management and therapy. The working group annually identifies topics that may significantly impact clinical practice and publishes expert opinion articles reflecting intersocietal collaboration, consensus, and suggestions for further research to address these important management issues. Summary: In 2019, the intersocietal working group identified the following topics for review and interdisciplinary discussion: (i) perioperative risk stratification, (ii) the role of diagnostic radioactive iodine (RAI) imaging in initial staging, and (iii) indicators of response to RAI therapy. Conclusions: The intersocietal working group agreed that (i) initial patient management decisions should be guided by perioperative risk stratification that should include the eighth edition American Joint Committee on Cancer staging system to predict disease specific mortality, the modified 2009 ATA risk stratification system to estimate structural disease recurrence, with judicious incorporation of molecular theranostics to further refine management recommendations; (ii) diagnostic RAI scanning in ATA intermediate risk patients should be utilized selectively rather than being considered mandatory or not necessary for all patients in this category; and (iii) a consistent semiquantitative reporting system should be used for response evaluations after RAI therapy until a reproducible and clinically practical quantitative system is validated.

18F-Choline (FCH) uptake parameters are strong indicators of aggressive disease in prostate cancer. Functional parameters derived by magnetic resonance imaging (MRI) are also correlated to aggressive disease. The aim of this work was to evaluate the relationship between metabolic parameters derived by FCH PET/CT and functional parameters derived by MRI.

BACKGROUND:Publication of the 2015 American Thyroid Association (ATA) management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer was met with disagreement by the extended nuclear medicine community with regard to some of the recommendations related to the diagnostic and therapeutic use of radioiodine (131I). Because of these concerns, the European Association of Nuclear Medicine and the Society of Nuclear Medicine and Molecular Imaging declined to endorse the ATA guidelines. As a result of these differences in opinion, patients and clinicians risk receiving conflicting advice with regard to several key thyroid cancer management issues. SUMMARY:To address some of the differences in opinion and controversies associated with the therapeutic uses of 131I in differentiated thyroid cancer constructively, the ATA, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association each sent senior leadership and subject-matter experts to a two-day interactive meeting. The goals of this first meeting were to (i) formalize the dialogue and activities between the four societies; (ii) discuss indications for 131I adjuvant treatment; (iii) define the optimal prescribed activity of 131I for adjuvant treatment; and (iv) clarify the definition and classification of 131I-refractory thyroid cancer. CONCLUSION:By fostering an open, productive, and evidence-based discussion, the Martinique meeting restored trust, confidence, and a sense of collegiality between individuals and organizations that are committed to optimal thyroid disease management. The result of this first meeting is a set of nine principles (The Martinique Principles) that (i) describe a commitment to proactive, purposeful, and inclusive interdisciplinary cooperation; (ii) define the goals of 131I therapy as remnant ablation, adjuvant treatment, or treatment of known disease; (iii) describe the importance of evaluating postoperative disease status and multiple other factors beyond clinicopathologic staging in 131I therapy decision making; (iv) recognize that the optimal administered activity of 131I adjuvant treatment cannot be definitely determined from the published literature; and (v) acknowledge that current definitions of 131I-refractory disease are suboptimal and do not represent definitive criteria to mandate whether 131I therapy should be recommended.

Comparer l’influx K1 obtenu par l’analyse dynamique et les paramètres SUV statiques obtenus en TEP choline avec les paramètres clinicopathologiques dans l’évaluation initiale des cancers de prostate. Trente-trois patients ont été inclus. Le taux sérique de Prostate-Specific Antigen (PSA) était mesuré quelques jours avant la TEP Choline. Les paramètres anatomopathologiques (Score de Gleason [GS], envahissement local [T] et envahissement ganglionnaire [N]) étaient obtenus après prostatectomie radicale et curage ganglionnaire. La TEP choline était composée de 2 phases : précoce pelvienne (de 0 à 10 minutes) et tardive corps entier (60 minutes après l’injection). Le volume d’intérêt (VOI) de la lésion tumorale prostatique était dessiné sur l’acquisition tardive avec un seuil adaptatif de Daisne et projeté sur la reconstruction statique précoce de 10 minutes et sur les 20 trames de 30 secondes reconstruites à partir de l’acquisition précoce. L’analyse dynamique utilisait une fonction d’entrée artérielle mesurée dans l’image pour chaque patient en utilisant le modèle à 2 compartiments réversibles. L’influx K1 obtenu par l’analyse dynamique et les paramètres statiques (SUVmoyen précoce et SUVmoyen tardif) étaient extraits et comparés aux données clinicopathologiques. K1 était modérément corrélé au SUVmoyen précoce (r = 0,57 ; p < 0,001) et au SUVmoyen tardif (r = 0,40 ; p = 0,02). Seul le SUVmoyen était corrélé au PSA (r = 0,43 ; p = 0,014). K1 était plus élevé pour les patients avec un GS 4 + 3 que les patients avec un GS < 4 + 3 dans une tendance quasiment significative (K1 médian à 0,392 min−1 vs 0,314 min−1 ; p = 0,068). Aucune différence n’était observée entre les patients avec un GS 4 + 3 et les patients avec un GS < 4 + 3 concernant les SUVmoyen précoce et SUVmoyen tardif. L’influx K1 obtenu par analyse dynamique semble lié au score de Gleason et pourrait être un paramètre intéressant non invasif pour renseigner sur le caractère agressif ou non d’un cancer de prostate.

The aim of the study was to compare the kinetic analysis of 18F-labeled choline (FCH) uptake with static analysis and clinicopathological parameters in patients with newly diagnosed prostate cancer (PC).

Suboptimal temporal sampling of time-activity curves (TAC) from dynamic 18F-fluoromethylcholine (FCH) PET images may introduce bias in quantification of FCH uptake in prostate cancer assessment. We sought to define an optimal temporal sampling protocol for dynamic FCH PET imaging.

Rechercher une éventuelle corrélation entre les paramètres métaboliques obtenus par TEP choline et les paramètres de diffusion et de perfusion obtenus par IRM dans le cancer de prostate. Les patients ayant un cancer de prostate prouvé venant pour bilan initial ou de récidive ayant une TEP choline et une IRM ont été prospectivement inclus. L’examen TEP choline était composé d’une acquisition pelvienne précoce en list-mode (0–10 min) et d’une acquisition tardive corps entier à 60 minutes. Une série statique d’une image de 10 minutes et une série dynamique de 12 × 5″ puis 3 × 30″ des 150 premières secondes du list-mode étaient reconstruites. Un volume d’intérêt (VOI) avec un seuil à 40 % était dessiné sur l’acquisition tardive et projeté dans l’acquisition statique précoce et dans chaque trame de la dynamique. Le paramètre dynamique représentant l’influx (K1) et les paramètres statiques (SUVmoyen précoce, SUVmoyen tardif et index de rétention) étaient extraits. Concernant l’examen IRM (1,5 T), après recalage de la diffusion avec l’acquisition TEP tardive, une VOI était dessinée sur l’IRM de diffusion et projetée sur les cartographies de perfusion. Le coefficient apparent de diffusion (ADC), la constante de transfert du gadolinium (ktrans) et le volume extra-cellulaire de gadolinium (Ve) étaient extraits. Une éventuelle corrélation entre tous ces paramètres était testée par la corrélation de Spearman. Treize patients étaient analysés avec 11 lésions intra-prostatiques et 2 lésions du lit de prostatectomie. Neuf patients venaient dans le cadre d’une récidive et 4 patients en initial. Le délai entre la TEP Choline était en moyenne de 39 jours. Concernant les paramètres TEP, il existait une corrélation statistiquement significative entre K1 et le SUVmoyen précoce (r = 0,61 ; p = 0,026) et entre SUVmoyen précoce et tardif (r = 0,85 ; p < 0,001). Aucune corrélation statistiquement significative n’était mise en évidence entre les paramètres IRM. Il était mis en évidence une corrélation statistiquement significative entre K1 et ktrans (r = 0,59 ; p = 0,035) et entre SUVmoyen précoce et ADC (r = −0,58 ; p = 0,04). L’influx de choline mesuré en TEP choline semble corrélé à la constante de transfert du gadolinium mesurée en IRM dans le cancer de prostate.

Objective - FCH-PET/CT protocol for prostate cancer assessment consists of an early and late acquisition. Concerning the early acquisition, this study compares contrast-to-noise ratio of tumoral lesions between 5 and 10 minutes post-injection in order to shorten the time of this early acquisition.Materials and methods - Patients with proven prostate cancer referred for initial staging or recurrence were prospectively included. Patients underwent 10 minutes of pelvic dynamic acquisition for the early phase and late phase was performed at 60 minutes post-injection. Contrast-to noise of lesions at 5 and 10 min post-injection were compared.Results - Forty-nine patients with 77 lesions were analyzed. No significant difference of prostatic lesions contrast-to-noise ratio was found between 5 min and 10 min post-injection (median contrast-to-noise ratio was respectively 38 and 42, P = 0.128).Conclusion - These results could have an impact on clinical practice with FCH-PET/CT early acquisition shortened to 5 min post-injection for patients with prostate cancer. (C) 2017 Elsevier Masson SAS. All rights reserved.

Nous présentons le cas d’un patient chez qui des nodules pulmonaires ont été retrouvés sur une TDM thoracique et dont l’histoire et les antécédents cliniques pouvaient faire suspecter soit une atteinte pulmonaire d’une neurofibromatose, soit une splénose thoracique. Le diagnostic définitif a pu être posé en médecine nucléaire sans avoir à recourir à d’autres méthodes diagnostiques plus invasives. Un patient de 53 ans, suivi pour une neurofibromatose de type I, aux antécédents de splénectomie d’hémostase 20 ans auparavant a été adressé pour dyspnée et douleur thoracique. L’ECG et la radiographie pulmonaire réalisés aux urgences étaient normaux. Le scanner thoracique retrouvait quant à lui des opacités nodulaires parenchymateuses et sous pleurales gauches. Une atteinte pleuropulmonaire due à des neurofibromes a été évoquée en premier lieu, bien qu’une splénose thoracique ne puisse être exclue chez ce patient. Une scintigraphie splénique aux globules rouges marqués au 99mTC a donc été proposée. L’analyse des images, réalisées par un balayage planaire corps entier complété d’une TEMP/TDM centrée sur la région thoracique, mettait en évidence de multiples foyers d’hyperfixation dans le champ pulmonaire gauche, correspondant aux lésions radiologiques initialement décrites. On retrouvait également d’autres foyers d’hyperfixation en région sous-diaphragmatique gauche. Le diagnostic de splénose thoracique a donc été retenu et une atteinte pulmonaire de la neurofibromatose a pu être éliminée. Ce cas clinique illustre l’intérêt de l’imagerie fonctionnelle pour le diagnostic différentiel de splénose, permettant ainsi d’éviter des procédures diagnostiques plus invasives ou inappropriées.

In medical imaging, the continuous quest to improve diagnostic performance and optimize treatment strategies has led to the use of combined imaging modalities. Positron emission tomography (PET) and computed tomography (CT) is a hybrid imaging existing already for many years. The high spatial and contrast resolution of magnetic resonance imaging (MRI) and the high sensitivity and molecular information from PET imaging are leading to the development of this new hybrid imaging along with hybrid contrast agents. To create a hybrid contrast agent for PET-MRI device, a PET radiotracer needs to be combined with an MRI contrast agent. The most common approach is to add a radioactive isotope to the surface of a small superparamagnetic iron oxide (SPIO) particle. The resulting agents offer a wide range of applications, such as pH variation monitoring, non-invasive angiography and early imaging diagnosis of atherosclerosis. Oncology is the most promising field with the detection of sentinel lymph nodes and the targeting of tumor neoangiogenesis. Oncology and cardiovascular imaging are thus major areas of development for hybrid PET-MRI imaging systems and hybrid contrast agents. The aim is to combine high spatial resolution, high sensitivity, morphological and functional information. Future prospects include the use of specific antibodies and hybrid multimodal PET-MRI-ultrasound-fluorescence imaging with the potential to provide overall pre-, intra- and postoperative patient care.

PURPOSE:Identifying gastroduodenal uptake of (99m)Tc-macroaggregated albumin (MAA), which is associated with an increased risk of ulcer disease, is a crucial part of the therapeutic management of patients undergoing radioembolization for liver tumours. Given this context, the use of MAA single photon emission computed tomography (SPECT)/CT may be essential, but the procedure has still not been thoroughly evaluated. The aim of this retrospective study was to determine the effectiveness of MAA SPECT/CT in identifying digestive extrahepatic uptake, while determining potential diagnostic pitfalls.METHODS:Overall, 139 MAA SPECT/CT scans were performed on 103 patients with different hepatic tumour types. Patients were followed up for at least 6 months according to standard requirements.RESULTS:Digestive, or digestive-like, uptake other than free pertechnetate was identified in 5.7% of cases using planar imaging and in 36.6% of cases using SPECT/CT. Uptake sites identified by SPECT/CT included the gastroduodenal region (3.6%), gall bladder (12.2%), portal vein thrombosis (6.5%), hepatic artery (6.5%), coil embolization site (2.1%) as well as falciform artery (5.0%). For 2.1% of explorations, a coregistration error between SPECT and CT imaging could have led to a false diagnosis by erroneously attributing an uptake site to the stomach or gall bladder, when the uptake actually occurred in the liver.CONCLUSION:SPECT/CT is more efficacious than planar imaging in identifying digestive extrahepatic uptake sites, with extrahepatic uptake observed in one third of scans using the former procedure. However, more than half of the uptake sites in our study were vascular in nature, without therapeutic implications. The risk of coregistration errors must also be kept in mind.

The goal of this study was to assess the use of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) analysis for vascularized volume measurements in the use of the yttrium-90-radiolabeled microspheres (TheraSphere). A phantom study was conducted for the validation of SPECT/CT volume measurement. SPECT/CT quantitative analysis was used for the measurement of the volume of distribution of the albumin macroaggregates (MAA; i.e., the vascularized volume) in the liver and the tumor, and the total activity contained in the liver and the tumor in four consecutive patients presenting with a complex liver vascularization referred for a treatment with TheraSphere. SPECT/CT volume measurement proved to be accurate (mean error <7%) and reproducible (interobserver concordance 0.99). For eight treatments, in cases of complex hepatic vascularization, the hepatic volumes based on angiography and CT led to a relative overestimation or underestimation of the vascularized hepatic volume by 43.2±32.7% (5–87%) compared with SPECT/CT analyses. The vascularized liver volume taken into account calculated from SPECT/CT data, instead of angiography and CT data, results in modifying the activity injected for three treatments of eight. Moreover, quantitative analysis of SPECT/CT allows us to calculate the absorbed dose in the tumor and in the healthy liver, leading to doubling of the injected activity for one treatment of eight. MAA SPECT/CT is accurate for volume measurements. It provides a valuable contribution to the therapeutic planning of patients presenting with complex hepatic vascularization, in particular for calculating the vascularized liver volume, the activity to be injected and the absorbed doses. Studies should be conducted to assess the role of quantitative MAA/SPECT CT in therapeutic planning.

We report a first experience involving the use of 90Y radiolabelled microspheres (TheraSphere) for the treatment of mainly primary hepatic tumours.

Objective Vectorized internal radiation therapy using lipiodol-labelled with iodine-131 ((131)I-lipiodol) is an effective treatment for inoperable hepatocellular carcinomas. However, few dosimetric data are available based on this approach. We have developed a dosimetric protocol based on scintiscan imaging and that is designed to calculate the tumoural absorbed dose during the treatment of hepatocarcinoma by (131)I-lipiodol.Methods This concept was developed on a gamma-camera coupled to a computed tomography scanner. It integrates corrections for attenuation phenomena, scattering and dead time. The tumoural absorbed dose calculation was carried out according to the Medical Internal Radiation Dose Committee formalism. This protocol was applied to a series of 41 patients in the framework of a retrospective study.Results The mean tumoural absorbed dose with the first treatment is 248 Gy (+/- 176), as opposed to 152 Gy (+/- 122) during the second. We highlighted a correlation between the tumoural absorbed dose, calculated in tomographic mode, and the morphological response to the first treatment (P=0.0071). Moreover, a tumoural absorbed dose of 280 Gy seems to be an effective absorbed dose threshold in our population. Above this absorbed dose, 84% of the patients are responders after the first treatment, whereas no responses are recorded below this threshold.Conclusion These results are promising because, for the first time, they allow us to predict the effectiveness of a treatment by (131)I-lipiodol. They are required to be validated on a broader exploratory trial, including a dosimetric study of the critical organs, so an individualized dosimetry can be defined for each patient.