The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of...最新文献

Background: The aim of this study is to evaluate the added value of early bone single photon emission computed tomography (SPECT) by comparison to pseudoplanar imaging.

Methods: Fifty patients were retrospectively included from 3 centers. Reading sessions were organized using: late-phase acquisition alone; early SPECT and late-phase acquisition; early pseudoplanar and late-phase acquisition. The comparison between early SPECT and MIP was performed using a McNemar Test. Patients for whom early SPECT had provided additional information were also compared with patients for whom early SPECT had not.

Results: Fifty patients were included. Early SPECT was superior to pseudoplanar MIP in 10/50 patients (20.0%, P=0.044). No significant difference was found between this group and the remainder. Early SPECT changed the diagnosis established from late-phase imaging in 21/50 patients.

Conclusions: Early SPECT is a promising tool in bone imaging and change the diagnosis in one fifth of the cases by comparison to pseudoplanar imaging.

Single photon emission computed tomography (SPECT) has revolutionized delayed bone scan acquisitions and promises to bring the same benefits to early acquisitions, especially in areas of complex anatomy. To date, however, only a few studies have been published about the utility of blood pool SPECT. The accurate assessment of inflammatory processes can be an indisputable added value to the diagnosis. We present here a series of clinical cases illustrating the utility of blood pool SPECT in various clinical situations in rheumatology and orthopedics. We grouped the cases according to three patterns that facilitate clinical reasoning: inflammatory osseous pathology (pattern A), inflammatory para-osseous pathology (pattern B) and inflammatory extra-osseous pathology (pattern C). A total of seventeen clinical cases are presented. This new semiology requires time and effort to be mastered but expands the diagnostic range offered by bone scintigraphy. More prospective studies on blood pool SPECT will be needed, especially those aiming to clarify its role.

Background: Left ventricular mechanical dyssynchrony (LVMD) and left ventricular function are intertwined. Gated myocardial perfusion SPECT (MPS) and gated fluorodeoxyglucose positron emission computed tomography (FDG PET) is an elegant way for repeated assessment of myocardial dyssynchrony and myocardial function. To the knowledge of the authors at the time this manuscript was prepared, there was no comprehensive evaluation of the interplay of LVMD and left ventricular function as measured by gated MPS and gated FDG PET; as well as no evaluation of the agreement between the two methods.

Methods: Patients were assigned to the reference cohort (RC) and the dyssynchrony cohort (DC) based on the phase analysis results of gated MPS datasets. Subsequently left ventricular function was analyzed.

Results: We demonstrated that LVMD as detected by gated MPS is associated with a significantly higher end-diastolic volume (EDV) and end-systolic volume (ESV) as well as a significantly reduced left ventricular ejection fraction (LVEF) both in gated MPS and gated FDG PET imaging. In the RC and the DC SPECT and PET showed good agreement and generally high linear correlations with regard to left ventricular volumes and LVEF. In the combined cohort (RC and DC) increasing amounts of LVMD were associated with increasing left ventricular volumes as well as a decreasing LVEF. The association was strongest for the dyssynchrony parameter Entropy.

Conclusions: We demonstrated that gated SPECT and gated PET are useful tools in the evaluation of left ventricular function in patients with LVMD as detected by gated MPS. Increasing amounts of dyssynchrony were associated with an increasingly reduced myocardial function. For repeated measurements or therapy monitoring, the methods should not be used interchangeably.

Background: Nivolumab is a monoclonal antibody that binds to the programmed death-1 (PD-1) receptor and blocks its interaction with PD-L1 and PD-L2. High response rates have been achieved with its use in the treatment of metastatic renal cell carcinoma (mRCC). We aimed to determine a relationship between 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) performed before nivolumab treatment and treatment-related survival.

Methods: Between 2014 and 2021, 32 patients who received nivolumab and had pre-treatment 18F-FDG-PET/CT evaluation were included in this retrospective study. The total SUVmax (sum of SUVmax) of all tumoral foci and the lesion with the highest SUVmax value were recorded. The relationship of these values with progression-free survival (PFS) and overall survival (OS) was evaluated.

Results: The median highest SUVmax and sum of SUVmax values were found as 14.4 and 41.4, respectively. PFS and OS were longer in the group with a sum of SUVmax value below 41.4 compared to the group with a higher group (OS, median 9.52 vs. 4.2 months [P=0.018]; PFS, median 9.6 vs. 3 months [P=0.003], respectively). In the group with the highest SUVmax value below 14.4, PFS was evaluated as statistically significant compared to the higher group (PFS, median 16.74 vs. 3.3 months [P=0.004]), while OS was not found to be statistically significant (OS, median 25.45 vs. 16.74 months (P=0.110)).

Conclusions: Our study showed that there might be a relationship between SUVmax values and PFS and OS. The SUVmax values before nivolumab treatment can be used to predict prognosis and survival in mRCC patients.

Background: During the past decade, ¹⁸F-fluorocholine (FCH) PET/CT has been continuously performed at Tenon Hospital (Paris, France) for the detection of hyperfunctioning parathyroid glands (PT).

Methods: A cohort of 401 patients, deliberately referred for HPT since September 2012, has been analyzed. The aim of this real-life retrospective study was to determine the diagnostic utility of FCH in this setting, overall and in subgroups according to the type of hyperparathyroidism (HPT), the context of FCH in the imaging work-up and in the patient's history: initial imaging or persistence or recurrence after previous parathyroidectomy (PTX). The influence of the histologic type of resected PTs, hyperplasia or adenoma, on the preoperatory detection on FCH PET/CT has been studied as well.

Results: Four hundred one FCH PET/CTs were included in the cohort, performed in 323 patients with primary HPT (pHPT), including 18 with familial HPT (fHPT), and in 78 patients with secondary renal HPT (rHPT). The overall positivity rate in the 401 FCH PET/CTs was 73%. The PTX rate was twice greater in patients whose FCH PET/CT was positive than negative (73% vs. 35%). Abnormal PT(s) were pathology proven in 214 patients: only hyperplastic gland(s) in 75 cases and at least one adenoma in 136 cases; FCH PET/CT sensitivity was 89% and 92%, respectively. Similarly, there was no significant difference in patient-based sensitivity whether FCH PET/CT was performed as 1^st line or later in the imaging work-up, or indicated for initial imaging or for suspicion of persistent or recurrent HPT. Gland-based sensitivity was significantly lower for hyperplasia than for adenoma (72% and 86%, respectively). The lowest gland-based sensitivity value was 65%, observed in case of hyperplasia and when FCH was performed late in the imaging work-up. FCH PET/CT correctly showed multiglandular HPT (MGD) in 36/61 proven cases, 59%. Results of ultrasonography (US) and ^99mTc-sestaMIBI (MIBI) imaging were available in 346 and 178 patients, respectively. For both modalities, the corresponding sensitivity values were significantly less than those of FCH PET/CT (e.g., overall gland-based sensitivity 78% for FCH, 45% for US, 30% for MIBI) and MGD was detected in 32% of cases by US and 15% by MIBI.

Conclusions: Although FCH PET/CT has been performed since 2017 as 1^st line imaging for HPT at Tenon Hospital (Paris, France), a large majority of patients underwent prior US and/or MIBI in their preoperative work-up. Therefore, a selection bias is very likely, as most patients referred to FCH PET/CT had non-conclusive or discordant results of US and MIBI, explaining the low performance of those modalities in the present cohort compared to published results. Nevertheless, the superiority of FCH PET/CT over US and MIBI in detecting abnormal PTs reported in various comparative stud

Background: To determine the thyroid uptake rate by correcting the background and analyze its clinical significance.

Methods: The study included 161 patients with hyperthyroidism. The thyroid uptake rate was calculated by drawing a 100 pixels ROI (region of interest) background, above and below the thyroid and correcting the thyroid ROI for background counting. At the same time, the clinical baseline characteristic parameters such as age and thyroid volume etc. of patients with hyperthyroidism were collected. The consistency of ^99mTcO4uptake rate before treatment and ¹³¹I-uptake rate after treatment, and the correlation between uptake rate of thyroid and baseline characteristic parameters were also analyzed.

Results: The uptake rate of ^99mTcO4 was found positively correlated with 3 h-radioactive iodine uptake (RAIU), 24 h-RAIU, 3 h/24 h conversion rate, thyroid volume, ¹³¹I activity free triiodothyronine (FT3) and free thyroxine (FT4), and showed negative correlation with age, effective half-life (P<0.05). The uptake rate of ¹³¹I was found positively correlated with 3 h-RAIU, 24 h-RAIU, 3 h/24 h conversion rate, thyroid volume, ¹³¹I activity, FT3, FT4 (P<0.05). In patients with positive thyrotrophin receptor antibody (TRAb), a significant positive correlation between uptake rate of ^99mTcO4 and ¹³¹I (P<0.05) was observed. There was a high consistency between pretreatment uptake rate of ^99mTcO4 and post-treatment uptake rate of ¹³¹I (P=0.009; W=0.7).

Conclusions: The corrected thyroid uptake rate is remarkably correlated with clinical characteristic parameters of patients, which can be used to comprehensively evaluate the comprehensive condition of patients with hyperthyroidism.

Background: To assess the detection rate of 18F-choline PET/CT in non-metastatic hormone-sensitive prostate cancer (hsPCa) and non-metastatic castrate resistant prostate cancer (CRPCa), based on the criteria proposed in the phase III SPARTAN trial and with high Gleason Score (GS).

Methods: Between October 2008 and September 2019, data from a retrospective multicenter study (N.=4 centers), involving patients undergoing ¹⁸F-choline PET/CT scans for a biochemical recurrence of PCa, were collected. The following inclusion criteria were used: 1) histologically proven PCa; 2) a non-metastatic disease in accordance with conventional imaging findings; 3) a PSA doubling time (PSAdt) <10 months; 4) a GS>8; and 5) no pelvic node>2 cm. The group of hsPCa and CRPCa patients, were compared by using a non-parametric statistical analysis. Moreover, a logistic regression analysis and ROC curves were used.

Results: One hundred forty patients were included. Of these, 82 patients were affected by hsPCa, and 58 had a CRPCa. Overall, 18F-Choline PET/CT was positive in 99/140 (70.7%). It was positive in 55/82 (67.1%) hsPCa patients and in 44/58 (75.9%) CRPCa subjects, respectively. The site of recurrence at 18F-Choline PET/CT were: 16 (27.6%) and 20 (24.4%) in prostatic bed, 25 (43.1%) and 24 (29.3%) in loco-regional lymph nodes and in 27 (46.6%) and 28 (34.1%) in distant organs, respectively for CRPCa and hsPCa patients. The optimal cut-off values for PSA at the time of PET/CT for the prediction or recurrence were 0.5 vs. 2.5 ng/mL for all site of recurrence (AUC: 0.70 vs. 0.72), 0.48 vs. 3.4 ng/mL for prostatic bed (AUC: 0.60 vs. 0.59), 0.5 vs. 1.5 for loco-regional lymph nodes (AUC: 0.62 vs. 0.57) and 2.2 vs. 2.8 ng/mL for distant metastasis (AUC: 0.74 vs. 0.71), respectively in CRPCa and hsPCa (all P=NS). Sensitivities and specificities of 18F-Choline PET/CT for the identification of recurrence disease in all patient population, in hsPCa and CRPCa were 83.7% and 87.5%, 78.9% and 88.9%, 91.4% and 85.7%, respectively.

Conclusions: The rate of positive 18F-Choline PET/CT is similar in patients with a hsPCa and CRPCa, in case of low PSAdt and high GS. Therefore, non-metastatic PCa patients should be assessed by molecular imaging, in order to adapt the most appropriate therapeutic approach.

Surgery is the only curative treatment for primary hyperparathyroidism (PHPT). Preoperative imaging is always recommended. ^99mTc-sestamibi scintigraphy is often used in combination with neck ultrasonography as first-line imaging. ^99mTc-sestamibi scintigraphy plays a major role in depicting ectopic parathyroid lesions, as well as in guiding a targeted, minimally invasive parathyroidectomy (MIP). Detecting multiple gland disease (MGD) is important to reduce the risks of surgical failure or unplanned conversion to bilateral surgery. However, the ability to recognize MGD varies greatly depending on the ^99mTc-sestamibi imaging protocol that is used. Dual-tracer ^99mTc-sestamibi/¹²³I highly improves MGD detection compared to single-tracer "dual-phase" ^99mTc-sestamibi imaging. It can thus improve patient selection for MIP. The main requirements for successful dual-tracer imaging are: 1) to acquire ^99mTc-sestamibi and 123-iodine images simultaneously, thus avoiding motion artifacts on subtraction images; to use neck pinhole imaging, in addition to planar imaging, to improve resolution and MGD detection; to follow with dual-tracer SPECT/CT imaging to better define anatomic position of detected parathyroid lesions. If dual-tracer ^99mTc-sestamibi/¹²³I and neck ultrasonography are negative or inconclusive, the second-line imaging in our practice is ¹⁸F-fluorocholine PET/CT. The CT component of ¹⁸F-fluorocholine PET/CT is performed as non-enhanced acquisition plus a contrast-enhanced arterial phase acquisition, to minimize the risk from false-positives due to choline uptake in inflammatory lymph nodes. We use the same strategy of first-line dual-tracer ^99mTc-sestamibi/¹²³I plus neck ultrasonography, followed if necessary by second-line contrast-enhanced ¹⁸F-fluorocholine PET/CT, in patients requiring reoperation for persistent or recurrent PHPT. Additional localization techniques are now rarely necessary.

Background: The most important cause of heart transplant loss is early acute allograft rejection, caused by the infiltration of lymphocytes, development of edema and myocardial necrosis. It has been propagated that [68Ga]DOTA-TATE PET might be suitable to quantify the presence of SSTR over-expressing lymphocytes. With heterotopic allogenic heart transplant models in the rat readily available, we aimed to investigate, if monitoring and quantification of acute allograft rejection after heterotopic allogenic heart transplantation was feasible by non-invasive serial [68Ga]DOTA-TATE PET.

Methods: Seventeen Lewis rats (9 for serial PET imaging, 8 for histological correlation) received allogenic heterotopic heart transplants from 17 Brown-Norway rats. On days 4, 6 and 7 a [68Ga]DOTA-TATE PET scan was performed.

Results: Imaging of acute transplant rejection until 7 days after allogenic heart transplantation in the rat is feasible. Heterotopic allografts showed significantly increased tracer uptake on day 4 until day 7 after transplantation, reflecting the process of histologically detected myocardial lymphocytic infiltration. Both the area of infarction and the amount of necrosis increased over the course of 7 days, with necrosis reaching statistical significance.

Conclusions: We purport that the detected PET signal is primarily a specific marker of lymphocyte infiltration and only to a lesser extent an unspecific marker of infarction and necrosis. Thus, [68Ga]DOTA-TATE PET might be a suitable tool for serial imaging and quantification of lymphocyte infiltration as a direct mediator of acute allograft rejection at an early stage after heart transplantation.

Introduction: Primary hyperparathyroidism (pHPT) is a common endocrine disorder caused by an autonomous overproduction of parathyroid hormone (PTH) by a parathyroid gland. Over the last decade, ¹⁸F-choline (FCH) PET has emerged as a highly performant imaging technique for guiding parathyroidectomy. As cure is the goal of surgery, the main aims of this study were to summarize patient-based sensitivity, positive predictive value (PPV), and cure rate of FCH PET guided surgery in the surgical management of pHPT.

Evidence acquisition: We conducted a systematic review and metaanalysis according to the PRISMA Guidelines. A literature search was performed in the PubMed, Web of Science and Cochrane databases, last updated November 2022. Original articles on choline PET in patients with pHPT mentioning patient-based sensitivity, PPV and cure rate were retained. Quality of included studies was assessed using the QUADAS-2 Tool. Patient-based sensitivity, PPV and cure rate were pooled by using a random-effects model.

Evidence synthesis: Twenty-three studies including 1716 patients were included for quantitative assessment. FCH PET showed a pooled patient-based sensitivity of 93.8% (95% CI: 89.8-96.3) and PPV of 97% (95% CI: 92.8-98.8) in patients with pHPT. Parathyroid surgery was performed in 1129 patients. The pooled cure rate of PET-guided surgery was 92.8% (95% CI: 87.4-96.0). Heterogeneity was shown to be moderate for all effect sizes.

Conclusions: FCH PET showed a high patient-based sensitivity, PPV and cure rate of PET guided surgery in patients with pHPT.