To evaluate the effect of the 18F-FDG PET-CT respiratory gating (4D) study in the correct documentation of pulmonary lesions with faint uptake in standard PET-CT.
Forty-two pulmonary lesions with a ...low or no detectable uptake of FDG (SUV(max) < 2.5) in 3D PET-CT were prospectively evaluated in 28 patients (19 males and 9 females), mean age 66.5 years (41-81). 22 patients had neoplastic background. A conventional PET-CT (3D) total body scan was performed approximately 60 min after iv injection of a mean dose of 370 MBq. Furthermore, a 4D PET-CT (synchronized with respiratory movement) thorax study was acquired. SUV(max) was determined for each lesion in both studies. For the 4D studies, we selected the SUV(max) in respiratory period with the highest uptake ("best bin"). We calculated the SUV(max) percentage difference between 3D and 4D PET-CT (% difference = SUV(max) 4D - SUV(max) 3D/SUV(max) 3D x 100) and the relation of this value with the size and locations of the lesions. In 4D study, any lesion with SUV(max) > or = 2.5 was classified as malignant. We assessed the changes of lesion classification (from benign to malignant) applying the 4D technique. The final diagnosis was obtained by histological assessment or clinical and radiological follow-up longer than 12 months.
Forty out of 42 lesions showed an increase of SUV(max) in the 4D study with respect to 3D. The mean SUV(max) in the 3D and 4D PET-CT studies were 1.33 (+/-0.59) and 2.26 (+/-0.87), respectively. The SUV(max) percentage difference mean between both techniques was 83.3% (+/-80.81).The smaller the lesion the greater was the SUV(max) percentage difference (P < 0.05). No differences were observed depending on the location of the lesion. In 40% of cases, there was a change in the final classification of lesions from benign to malignant. In the final diagnosis, 24 lesions were malignant. 4D PET-CT diagnosed correctly the 52% of them.
The 4D PET-CT study permitted a better characterization of malignant lung lesions compared with the standard PET-CT, because of its higher sensitivity. 4D PET-CT is a recommendable technique in the early diagnosis of malignant lesions.
Aim
To evaluate the effect of the 18F-FDG PET-CT respiratory gating (4D) study in the correct documentation of pulmonary lesions with faint uptake in standard PET-CT.
Methods
Forty-two pulmonary ...lesions with a low or no detectable uptake of FDG (SUV
max
< 2.5) in 3D PET-CT were prospectively evaluated in 28 patients (19 males and 9 females), mean age 66.5 years (41–81). 22 patients had neoplastic background. A conventional PET-CT (3D) total body scan was performed approximately 60 min after iv injection of a mean dose of 370 MBq. Furthermore, a 4D PET-CT (synchronized with respiratory movement) thorax study was acquired. SUV
max
was determined for each lesion in both studies. For the 4D studies, we selected the SUV
max
in respiratory period with the highest uptake (“best bin”). We calculated the SUV
max
percentage difference between 3D and 4D PET-CT (% difference = SUV
max
4D − SUV
max
3D/SUV
max
3D × 100) and the relation of this value with the size and locations of the lesions. In 4D study, any lesion with SUV
max
≥ 2.5 was classified as malignant. We assessed the changes of lesion classification (from benign to malignant) applying the 4D technique. The final diagnosis was obtained by histological assessment or clinical and radiological follow-up longer than 12 months.
Results
Forty out of 42 lesions showed an increase of SUV
max
in the 4D study with respect to 3D. The mean SUV
max
in the 3D and 4D PET-CT studies were 1.33 (±0.59) and 2.26 (±0.87), respectively. The SUV
max
percentage difference mean between both techniques was 83.3% (±80.81).The smaller the lesion the greater was the SUV
max
percentage difference (
P
< 0.05). No differences were observed depending on the location of the lesion. In 40% of cases, there was a change in the final classification of lesions from benign to malignant. In the final diagnosis, 24 lesions were malignant. 4D PET-CT diagnosed correctly the 52% of them.
Conclusions
The 4D PET-CT study permitted a better characterization of malignant lung lesions compared with the standard PET-CT, because of its higher sensitivity. 4D PET-CT is a recommendable technique in the early diagnosis of malignant lesions.
Aim
To analyze the prognostic role of sentinel lymph node biopsy (SLNB) in patients with cutaneous malignant melanoma (MM).
Methods
A retrospective study was conducted including patients with ...histologically proven and surgically resected MM with subsequent SLNB and clinical follow-up for at least 18 months. A survival analysis was performed using Kaplan–Meier method and univariate and multivariate Cox regression.
Results
Two hundred and twenty-three consecutive patients (one hundred and one women) undergoing SLNB after MM diagnosis between 2011 and 2020 were included, ranging from 20 to 87 years (mean = 57.34 ± 15.03 years). SLNB was positive for malignancy in 50/223 patients and post-SBLN staging was: Ia = 65; Ib = 40; IIa = 31; IIb = 27; IIc = 10; IIIa = 11; IIIb = 9 and IIIc = 30. Breslow (p < 0.001), Clark level (
p
= 0.001), mitosis rate (
p
= 0.001) and histologic type (
p
= 0.038) were associated significantly with the presence of lymph node metastases. SLNB result was a significant factor in overall survival (OS) (
p
< 0.001) and progression-free survival (PFS) (
p
< 0.001) showing a lower OS in patients with positive SLNB compared to those with negative. Univariate and multivariate Cox regression analyses showed that positive SLNB, lymphovascular invasion, and age were independents risk factor for OS and PFS.
Conclusion
In our experience, and in accordance with the literature, detection of lymph node metastases by SLNB is a marker of tumor aggressiveness being associated with patient outcome.
To investigate the applicability of the sentinel lymph node biopsy technique in early stages of endometrial cancer.
A prospective study that included consecutive patients with a histological ...diagnosis of clinical state I endometrial carcinoma was performed. Two doses of 2 mCi (74 MBq) of (99m)Tc-albumin nanocolloid were injected in the uterine cervix, and planar and SPECT-CT images were obtained at one hour, and at 24 hours if no migration of the tracer was observed. Methylene blue dye was also injected into the cervix immediately prior to the surgery. A gamma probe was used during the surgical procedure for sentinel lymph node identification. In all cases, a hysterectomy, double adnexectomy and pelvic lymphadenectomy were performed, carrying out a histological analysis (hematoxylin-eosin) of the sentinel lymph nodes and the lymphadenectomy specimen.
We included 19 patients, with a final diagnoses of endometrioid carcinoma (18 cases) and endometrial stromal sarcoma (1 case). At least one sentinel lymph node was identified in 17 of them (89.5% detection rate). Twenty-nine sentinel lymph nodes were identified during surgery, all of them negative for neoplastic infiltration. No metastatic invasion was found in the pelvic lymphadenectomy specimens as well.
The sentinel lymph node biopsy technique seems to be a reliable tool in nodal staging of endometrial cancer at early stages, with an acceptable detection rate and high histological correlation. The low prevalence of lymphatic spread in this group of patients and the encouraging results obtained could make the sentinel lymph node an alternative to routine complete lymphadenectomy.
To compare two different methods for the interpretation of interim PET/CT (PET/CT-i) in lymphomas, and to establish which one best predicts a complete metabolic response (CMR) in the PET/CT study at ...the end of treatment (PET/CT-et).
Retrospective longitudinal analysis of the PET/CT studies for staging (PET/CT-s), PET/CT-i and PET/CT-et of 65 patients, 35 Hodgkin's lymphoma (HL) and 30 Non-HL. The PET/CT-i was performed between the second and fourth chemotherapy cycle. It was interpreted using two different criteria: qualitative criteria (5 point visual scale), semiquantitative criteria (percentage difference between the lesion with more SUVmax in the PET/CT-s and PET/CT-i). We analyzed the likelihood of obtaining a CMR in the PET/CT-et according to the results obtained on the PET/CT-i with these two criteria.
We obtained sensitivity (S), specificity (Sp), positive predictive values (PPV), negative predictive values (NPV) and likelihood ratio (LR) for the qualitative/semiquantitative method of 91%/80%, 76.2%/67%, 88.9%/83.3%, 80%/60.9% and 32%/7.8%, respectively, to predict a CMR in the PET/CT-et. There were no statistically significant differences between the LR of both methods (p=0.1942).
We found clear differences in S, Sp, PPV and NPV between both interpretation criteria for the PET/CT-i to predict a CMR in the PET/CT-et. Nevertheless, we cannot confirm the superiority of the qualitative method over the semiqualitative method for this purpose as no statistically significance differences were found in their LR in our study.
To describe the process of implementing a quality management system according to UNE-EN-ISO 9001:2008 standard in a Nuclear Medicine Department.
In February 2008, the committee on internal quality of ...the Department was established, naming a responsible physician. The general operating plan was drawn up, following the requirements established by the ISO 9001:2008 standard. It defined the scope of the standard, defining, preparing and transcribing the various activities of our Department. Four training sessions were carried out.
A total of nine general and two specific procedures were documented in which all the activities performed in our Department were included. Personnel records of each worker were created, including their profiles and training plan. A record of the equipment and service providers was created, as well as issues with the latter. Satisfaction surveys were obtained from external (patients) and internal customers (faculty applicants). Targets for improvement and activity markers were established. Two audits were performed to complete the process, one internal and one external. The Department was accredited in April 2010.
The quality accreditation process is a tool that requires reflection on how we do things and how they can be improved. It makes it possible to measure what we do, to analyze and introduce improvement measures, and therefore, to achieve a higher level of quality in the service we provide our customers. The involvement of the Department workers with a commitment to team performance was essential.
AIMTo assess the diagnostic accuracy of 18F-FDG PET/contrast enhanced computed tomography (ceCT) in the detection of asymptomatic recurrences in patients with lymphoma. MATERIAL AND METHODSPatients ...with lymphoma and clinical complete remission underwent 18F-FDG PET/ceCT for standard follow-up.18F-FDG PET and ceCT were evaluated blindly by two independent observers, and classified as positive or negative for recurrence. Additionally a combined evaluation of both techniques was performed. The final diagnosis was established by histopathological analysis or a clinical follow-up longer than 6 months. Statistical diagnostic parameters and concordance levels between both diagnostic techniques were calculated. RESULTSA total of 114 explorations on 90 patients were analyzed. Only 4 patients were diagnosed as asymptomatic recurrence during the follow-up. 18F-FDG PET/ceCT, 18F-FDG PET and ceCT showed an association with the final diagnosis (p=0.002 and χ2=11.96; p<0.001 and χ2=15.60; p=0.001 and χ2=11.96, respectively). The concordance between 18F-FDG PET and ceCT was moderate/high and significant (kappa=0.672; p<0.001). A sensitivity and specificity of 50% and 88% was obtained for the 18F-FDG PET/ceCT civ, 50% and 93% for the 18F-FDG PET, and 50% and 91% for the ceCT. CONCLUSIONThe combined use of 18F-FDG PET/ceCT did not offer any advantage compared to any isolated diagnostic technique in the detection of asymptomatic lymphoma recurrence.
Abstract
Introduction
Both atrial and ventricular pacing (AP/VP) have been related to a higher risk of clinical atrial fibrillation (AF) documented on ECG. Subclinical AF is detected as atrial high ...rate episodes (AHRE) by cardiac implantable electronic devices and is related to a higher risk of stroke.
Purpose
The aim of this study was to determine whether the percentage of AP and/or VP in patients with pacemakers and no history of AF is related with the future development of subclinical AF (AHRE) and/or clinical AF (ECG documented).
Methods
From February 2012 to September 2015 we recruited patients with dual chamber pacemakers and no prior history of AF. Patients were followed at 3 months and every year then after. Subclinical AF, clinical AF and cardiovascular events were registered. AHRE (subclinical AF) was defined as an episode of atrial rate ≥225 bpm with a minimum duration of 5 min. Clinical AF was defined as ECG documented AF. Percentage of AP/VP was determined as the mean AP/VP during the first three visits. Mortality and cardiovascular events (including AF, stroke and hospitalization for heart failure) were also recorded.
Results
249 patients (57% men; 75±9 years-old) were included. Mean time from pacemaker implantation was 9 months and the main indication was AV-block in 53% of the patients. Mean CHA2DS2-VASc score was 3.5±1.5. After a mean follow-up of 33±11 months, 38.5% of patients developed subclinical AF and 10.4% clinical AF. Patients with AP≥50% presented significantly higher risk of AHRE (62.5% vs 32.3%, OR 3.48; 95% CI 1.93–6.4 p<0.01) and clinical AF (18.7% vs 8.6%, OR 2.4; 95% CI 1.05–5.52 p<0.05). Patients with VP≥50% presented significantly higher risk of AHRE (46.4% vs 31.6%, OR 1.87; 95% CI 1.10–3.24 p<0.05) and clinical AF (25.9% vs 9.7%, OR 2.7; 95% CI 1.13–7.72 p<0.05). The percentage of AP and VP were not related to a higher risk of cardiovascular events or mortality. Multivariate analysis showed that AP≥50% was an independent predictor for AHRE (OR 2.4; 95% CI 1.19–4.97 p=0.014).
Conclusions
Pacing is related to a higher risk for developing subclinical and clinical AF in patients with dual-chamber pacemakers and no history of previous AF. Our data suggest, that patients presenting a high percentage of AP and VP should be closely followed during routinely pacemaker check-ups assessing for subclinical AF, especially in those with AP ≥50%.
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