Revista Espanola De Medicina Nuclear E Imagen Molecular最新文献

Aim

To determine the usefulness of neutrophil/lymphocyte (N/L) and platelet/lymphocyte (P/L) ratios as well as quantitative [¹⁸F]FDG PET/CT parameters as prognostic factors for overall survival (OS), cancer-specific survival (CSS) and progression-free survival (PFS) in patients with head and neck squamous cell carcinoma (HyN).

Material and methods

Sixty-six patients (56 men) diagnosed with HyN carcinoma were retrospectively assessed over an 8-year interval. Maximum SUV (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) parameters were determined from the PET/CT study at diagnosis. After treatment with chemoradiotherapy, patient survival was assessed. The Cox regression model and the Kaplan-Meier method were used to analyse prognostic factors and survival curves.

Results

Median follow-up was 50.4 months, with 39 recurrences-progressions and 39 deaths. In the univariate analysis, metabolic parameters, except SUVmax, were predictive factors for all three survivals and the two blood parameters were predictive for OS and EFS. TLG was the only predictive factor in the multivariate analysis. The three survival curves were significantly different for the metabolic parameters and the OS curve for the N/L ratio. Correlations were seen between N/L ratio, MTV and TLG. No correlations were demonstrated between P/L ratio and metabolic parameters.

Conclusion

The use of haematological and metabolic markers would allow to identify patients with a high risk of recurrences and poor survival and to individualise treatment by applying more aggressive therapies.

Introduction

Amino acid PET is a tool recommended by the main neuroimaging societies in the differential diagnosis between radionecrosis (RNC) and tumour recurrence (TR) in brain tumours, but its use in our country is still limited. The aim of this work is to present our experience with 6-[¹⁸F]FDOPA PET/CT (FDOPA) in brain tumours (primary and M1), comparing these results with other published results.

Material and methods

Retrospective study of 62 patients with suspected tumour recurrence (TR): 42 brain metastases (M1) and 20 primary, who underwent FDOPA. Images were analysed visually and semi-quantitatively, obtaining SUV_max and SUV_maxlesion/SUV_maxstriatum (L/S) and SUV_maxlesion/SUV_maxcortex (L/C) ratios. The diagnostic validity of PET was analysed and the best performing cut-off points were calculated. PET results were compared with clinical-radiological follow-up and/or histopathology.

Results

TR was identified in 49% of M1 and 76% of brain primaries. The best performing FDOPA interpretation was visual and semi-quantitative, with a sensitivity and specificity in primaries of 94% and 80% and in M1s of 96% and 72% respectively. The cut-off points with the best diagnostic performance were L/C1.44 in M1 and L/C1.55 in primaries. There are discrepant results with other published results.

Conclusion

FDOPA PET/CT is a useful tool in the differential diagnosis between recurrence and RNC in brain tumours. It is needed a standardization to contribute to homogenise FDOPA results a inter-centre level.

Since its origins, nuclear medicine has faced technological changes that led to modifying operating modes and adapting protocols. In the field of radioguided surgery, the incorporation of preoperative scintigraphic imaging and intraoperative detection with the gamma probe provided a definitive boost to sentinel lymph node biopsy to become a standard procedure for melanoma and breast cancer.

The various technological innovations and consequent adaptation of protocols come together in the coexistence of the disruptive and the gradual. As obvious examples we have the introduction of SPECT/CT in the preoperative field and Drop-in probes in the intraoperative field. Other innovative aspects with possible application in radio-guided surgery are based on the application of artificial intelligence, navigation and telecare.

Objective

To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[¹⁸F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAF^V600E mutation.

Materials and methods

The 2-[¹⁸F]FDG PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test.

Results

Out of the 19 patients (14 males; mean age 60.3 years), 11 had the BRAF^V600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAF^V600E mutation was associated with greater organ involvement (P < .05) without differences in SUVmax (P > .05).

Conclusion

2-[¹⁸F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[¹⁸F]FDG (cerebral and cardiac). The presence of the BRAF^V600E mutation correlated with a higher extent of the disease.

Introduction

The non-invasive diagnostic study of cardiovascular risk in patients who are going to undergo liver transplantation is not clear, especially in asymptomatic patients. Regarding myocardial perfusion scintigraphy (MPS), it has been thought that the impaired vasodilator reserve in these patients may reduce its performance. The objective is to assess the role of the MPS in the pre-surgical evaluation of patients who are going to undergo liver transplantation.

Material and methods

Retrospective, descriptive and observational study was designed. All adult patients undergoing liver transplantation between 2017 and 2021 who had previous MPS were included. The findings of MPS were described and correlated with the findings of invasive angiography and with the appearance or not of peri- and post-transplant cardiovascular events.

Results

There were a total of 188 transplanted patients (mean age: 57 years, SD: 12), 178 had previous myocardial perfusion, 82 (46%) patients had no cardiovascular risk factors, and 5 (2.8%) had a history of coronary disease.

Of the MPS, 177 were with dipyridamole stress performed on average 10 months before transplantation. Only 17/178 (9.5%) studies were abnormal. The mean follow-up was 38 months (SD: 10). Of the patients with normal MPS, only 2 (1.2%) presented cardiovascular events, both with studies performed more than 2 years before the procedure. There were no deaths of cardiovascular origin.

Conclusions

MPS is a safe and reliable technique for cardiovascular assessment of patients who are candidates for liver transplantation, given the low rate of false negatives during follow-up.

Polymyalgia rheumatica (PMR) is an inflammatory joint disease that presents in patients older than 50 years with prolonged morning pain and stiffness in the shoulder and hip joints and neck. The lack of specific clinical findings, laboratory signs, biomarkers and established imaging methods makes it difficult to diagnose patients with this disease. 18F-FDG PET/CT is a functional imaging technique that is an established tool in oncology and has also proven useful in the field of inflammatory diseases. The aim of this paper is to present literature evidence on the use of molecular imaging methods such as PET/CT for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of other methods are considered.

Purpose

To evaluate the diagnostic performance of a novel deep learning attenuation correction software (SAPCA) for myocardial perfusion imaging (MPI) using a cadmium-zinc-telluride (CZT) cardio dedicated camera with invasive coronary angiography (ICA) correlation for the diagnosis of coronary artery disease (CAD) in a high-risk population.

Methods

Retrospective study of 300 patients (196 males [65%], mean age 68 years) from September 2014 to October 2019 undergoing MPI, followed by ICA and evaluated by means of quantitative angiography software, within six months after the MPI. The mean pre-test probability score for coronary disease according to the European Society of Cardiology criteria was 37% for the whole cohort. The MPI was performed in a dedicated CZT cardio camera (D-SPECT® Spectrum Dynamics) with a two-day protocol, according to the European Association of Nuclear Medicine guidelines. MPI was retrospectively evaluated with and without the SAPCA.

Results

The overall diagnostic accuracy of MPI without SAPCA to identify patients with any obstructive CAD at ICA was 87%, Sensitivity 94%, Specificity 57%, positive predictive value 91% and negative predictive value 64%. Using SAPCA the overall diagnostic accuracy was 90%, sensitivity 91%, specificity 86%, positive predictive value 97% and negative predictive value 66%.

Conclusion

Use of the novel SAPCA enhances performance of the MPI using the CZT D-SPECT® camera and achieves improved results, especially avoiding artefacts and reducing the number of false positive results.