Clinical and Translational Imaging最新文献

Introduction

Extramedullary disease (EMD) represents an aggressive manifestation of multiple myeloma (MM), characterized by autonomous cancer clone growth outside the bone marrow. Despite the International Myeloma Working Group’s endorsement of 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/CT ([¹⁸F]FDG PET/CT) for assessing EMD patients, a consensus on the imaging workup in this distinctive clinical context is lacking.

Methods

In this pictorial essay, we collected clinical MM cases from eight high-volume Italian PET/CT clinical centers. Each center checked its database to identify the most representative and unusual EMD cases detected on [¹⁸F]FDG PET/CT. Subsequently, the selected cases underwent consensus discussion among the authors, prioritizing those deemed clinically relevant.

Results

The selected cases demonstrate a diverse range of manifestations, including leptomeningeal involvement, two instances of pancreatic masses, two renal/para-renal localizations, one skin localization, one pleural involvement, one adnexal/fallopian involvement, and one suspected neck nodal localization later confirmed as lymphoma upon histological examination.

Conclusions

These cases underscore the highly variable presentations of EMD on [¹⁸F]FDG PET/CT. EMD can manifest with widespread anatomical localization as either single or multiple lesions. Tracer uptake patterns also vary in terms of intensity and homogeneity. In patients with a history of MM, nuclear medicine physicians should be vigilant for possible EMD localizations, not only at the time of diagnosis but as well as recurrence setting, with or without concurrent bone involvement.

Objective

This study explores the diagnostic value of quantitative parameters from ⁶⁸Ga-FAPI-04 PET/CT and ¹⁸F-FDG PET/CT in the detection of mediastinal lymph node metastasis in non-small cell lung cancer (NSCLC) patients.

Methods

Seventeen NSCLC patients patients undergoing imaging with FAPI and FDG were included in the study. Measurements were taken for short diameter, long diameter, density of mediastinal lymph nodes, as well as SUVmax of mediastinal blood pool (MBP- SUVmax), primary tumor (PT-SUVmax), and lymph nodes (LN-SUVmax) in both imaging modalities. LN-SUVmax / MBP- SUVmax, LN-SUVmax / PT-SUVmax, and LN-SUVmax /short diameter ratios were calculated for lymph nodes. Statistical differences between the parameters of imaging modalities in the mediastinal lymph node metastasis group and the non-metastasis group were analyzed. Statistical differences between FAPI and FDG imaging parameters were also compared. Receiver Operating Characteristic (ROC) curves were utilized to determine optimal diagnostic thresholds, along with corresponding sensitivity, specificity, and area under the curve (AUC) for each parameter in the detection of mediastinal lymph node metastasis.

Results

In FAPI imaging, LN-SUVmax, LN-SUVmax / MBP- SUVmax, LN-SUVmax / PT-SUVmax, and LN-SUVmax /short diameter were higher in the mediastinal lymph node metastasis group compared to the non-metastasis group, with statistical significance (p < 0.05). In FDG imaging, only LN-SUVmax / PT-SUVmax was higher in the mediastinal lymph node metastasis group, with statistical significance (p < 0.05). Two parameters (LN-SUVmax/MBP-SUVmax, LN-SUVmax/PT-SUVmax) in the FAPI group and three parameters (LN-SUVmax, LN-SUVmax/MBP-SUVmax, LN-SUVmax/short diameter) in the FDG group showed positive and negative correlations, respectively, in the mediastinal lymph node metastasis and non-metastasis groups, all with statistical significance (p < 0.05). The AUC of FAPI imaging for LN-SUVmax (0.907 vs. 0.667) and LN-SUVmax/PT- SUVmax (0.772 vs. 0.704) were higher compared to FDG imaging, with statistical significance (p < 0.05).

Conclusion

⁶⁸Ga-FAPI-04 PET/CT imaging exhibits a certain advantage over ¹⁸F-FDG PET/CT in the detection of mediastinal lymph node metastasis in NSCLC patients, suggesting potential clinical value in the staging of NSCLC patients.

Background

[¹⁸F]FDG-PET/CT is a sensitive non-invasive tool for assessing treatment response in patients with pulmonary tuberculosis. The data on the performance of [¹⁸F]FDG-PET/CT for response assessment among patients infected with the human immunodeficiency virus (HIV) is limited. Here, we investigated the differences between PET and CT lung findings on end-of-treatment [¹⁸F]FDG-PET/CT among HIV-positive versus HIV-negative patients who completed anti-tuberculous therapy for pulmonary tuberculosis.

Methods

Patients who completed anti-tuberculous therapy for pulmonary tuberculosis and declared cured based on negative clinical and laboratory assessments for active pulmonary tuberculosis were prospectively recruited to undergo [¹⁸F]FDG-PET/CT. Patients were classified as having residual metabolic activity if PET metabolic activity was demonstrated in the lung parenchyma or complete metabolic response if there was no abnormally increased [¹⁸F]FDG avidity in the lungs and compared the CT features. We identified 10 CT lung changes, five were associated with active pulmonary tuberculosis (nodules, micronodules in tree-in-bud pattern, consolidation, pleural effusion, and [¹⁸F]FDG-avid mediastinal/hilar lymphadenopathy) and the rest were associated with inactive sequelae of prior pulmonary tuberculosis (cysts, cavities, fibrosis, bronchiectasis, and calcifications and compared their incidence between HIV-positive and HIV-negative patients.

Results

Seventy-five patients were included with a mean age of 36.09 ± 10.49 years. There were fifty HIV-positive patients, all of whom were on antiretroviral therapy and with a median CD4 + T-cell of 255 cells/µL (IQR: 147–488). Fifteen HIV-positive patients had detectable HIV viremia with a median viral load of 12,497 copies/mL (IQR: 158–38,841). There was a significant difference in the incidence of residual metabolic activity and complete metabolic response between HIV-positive and HIV-negative patients. (P = 0.003) HIV-positive patients were more likely to have [¹⁸F]FDG-avid lymphadenopathy and HIV-negative patients had a higher incidence of cystic lung changes. The pattern of CT lung changes was otherwise not different between HIV-positive and HIV-negative patients. (P > 0.05)

Conclusions

The incidence of residual metabolic activity and complete metabolic response on end-of-treatment [¹⁸F]F-FDG-PET/CT are similar between HIV-positive and HIV-negative patients. The incidence of [18F]FDG-avid mediastinal/hilar lymphadenopathy is more prevalent among HIV-positive patients. The pattern of lung changes was largely similar between HIV-positive and HIV-negative patients, indicating that the presence of HIV coinfection may not influen

Introduction

Radioactive iodine (RAI) therapy is part of the treatment option for Graves’ disease, and it is widely accepted to be safe. However, some evidence suggests its association to a small increased risk of thyroid cancer and rarely to an aggressive form of thyroid carcinoma.

Case report

Here, we report a case of anaplastic thyroid carcinoma (ATC) following RAI treatment for Graves’ disease. A 48 year-old woman had been diagnosed with Graves’ disease and thyroid nodules. A single RAI treatment had been performed after an unsuccessful medical therapy approach. More than 10 years later, the patient was admitted to our clinic due to dysphonia, weight loss and a rapidly growing neck mass. Thyroid ultrasound and neck computed tomography suggested a thyroid carcinoma and she was diagnosed with a V600E BRAF-mutated ATC. She was given carboplatin, paclitaxel, and radiotherapy. The patient died a few months after the first symptoms of the disease occurred.

Discussion

It is not clear if the occurrence of ATC could be influenced by the RAI therapy for hyperthyroidism. Therefore, we reviewed the different cases and characteristics of ATC after RAI published so far in the literature. Patients were exclusively females, the median age at diagnosis was 66,5 years old (IQR: 51,5–69, range 29–75) and the median time occurring from RAI treatment and ATC diagnosis was 7 years. To our knowledge, here we report the first patient with V600E BRAF-mutation in ATC after RAI for Graves’ disease.

Background

Osteosarcomas (OSTs) and Ewing’s sarcomas (EWSs) present significant challenges in pediatric and adolescent oncology due to their diverse pathological features and clinical behaviors. The advent of [¹⁸F]fluoro-2-deoxy-2-d-glucose positron emission tomography ([¹⁸F]FDG PET) has introduced new potential prognostic parameters, such as the SUVmax, MTV, and TLG, but their predictive value in patients with OST and EWS remains debatable.

Methods

This systematic review and network meta-analysis were conducted in accordance with PRISMA-NMA guidelines. A comprehensive literature search covered studies from the last 15 years on [¹⁸F]FDG PET metabolic parameters in patients with OST and EWS. The prognostic value of [¹⁸F]FDG PET parameters, including pre- and posttreatment standardized uptake values (SUV1, SUV2 and the SUV2/SUV1 ratio), metabolic tumor volume (MTV1, MTV2) and total lesion glycolysis (TLG1, TLG2), on event-free survival and overall survival in patients with OST and EWS was examined. The data analysis involved traditional and network meta-analyses (NMA), including subgroup analyses and meta-regression.

Results

Our analysis included 20 studies with 858 patients. We found significant associations between higher SUV1, SUV2, MTV1 and TLG1 and survival outcomes. The NMA revealed the superior predictive strength of SUV2, MTV, and TLG over SUV1. Subgroup analysis highlighted the variable prognostic value of these parameters, particularly between pediatric and adult patients.

Conclusion

Our study suggested that [¹⁸F]FDG PET parameters, particularly SUV2, MTV1, and TLG1, have significant prognostic value in patients with OST and EWS. Further research involving larger cohorts and standardized methodologies is essential to confirm and build upon these findings.

Aim

Dopamine is one of the major neurotransmitters of the central nervous system. Dopamine is involved in various cerebral and peripheral physiological functions and pathological conditions. The aim of this mini review is to overview the dopamine, PET radiotracers of dopaminergic system and their clinical applications.

Methods

Dopamine synthesis, dopamine receptors, role of dopamine in physiological functions and diseases, PET radiotracers of dopaminergic system and their clinical applications were reviewed.

Results

There is a large number of PET radiotracers to assess various elements of dopaminergic system such as F-18 fluorodopamine to assess dopamine transfer and storage in peripheral catecholamine-synthesizing cells, F-18 FDOPA to assess L-DOPA transfer via l-amino acid transporters, conversion of L-DOPA to dopamine by aromatic l-amino acid decarboxylase and storage of dopamine at vesicles, C-11 methylphenidat, C-11 dihydrotetrabenazine, and C-11 deprenyl to assess dopamine transport via dopamine transporters, dopamine transport into vesicles by vesicular monoamine transporter-2, and dopamine degredation by monoamine oxidase, respectively, in presynaptic dopaminergic nerve terminals in the brain and in certain peripheral cells and C-11 raclopride and C-11 SCH 23,390 to assess dopamine receptors at postsynaptic nerve terminals. Among these radiotracers, only F-18 FDOPA is widely and commercially available. The other radiotracers are available in limited centers, mainly for research purpose. Dopaminergic PET radiotracers help to detect or diagnose various diseases such as parkinsonian syndromes, huntington’s disease, dementias, schizophrenia, drug addictions, paragangliomas, pheochromocytoma, medullary thyroid carcinoma, gut carcinoids, gliomas and hyperinsulinemic hypoglycemia.

Conclusion

There is a large number of dopaminergic PET radiotracers which help to detect or diagnose diseases of the various systems in which dopaminergic system is involved.

Purpose

This study aims to explore the long-term effects on parathyroid function and risk factors associated with permanent hypoparathyroidism (HPT) in differentiated thyroid cancer (DTC) patients treated with ¹³¹I.

Methods

201 postoperative DTC patients were included. Serum levels of parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-VD), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) were collected before (baseline) and after ¹³¹I treatment. Patients were divided into permanent HPT group and non-permanent HPT group, and risk factors were analyzed using penalized logistic regression (PLR).

Results

There were no statistically significant differences in serum levels of PTH, 25-OH-VD, Ca, P, and ALP among the five time points (baseline, 6 months, 12 months, 24 months, and 36 months) (P > 0.05). Multivariate PLR analysis revealed that the presence of functional metastases in the first ¹³¹I-SPECT/CT-whole-body scan (¹³¹I-WBS) was a significant risk factor for permanent HPT (OR = 21.392, P < 0.05).

Conclusions

Postoperative ¹³¹I therapy for DTC has no significant adverse effects on the parathyroid function within three years, but extremely few patients still develop permanent HPT, with an increased risk in those with functional metastases in the first ¹³¹I-WBS.