The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease.

OBJECTIVE: To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18 F]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 BRAFV600E 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 BRAFV600E 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 BRAFV600E mutation was associated with greater organ involvement (p < 0.05) without differences in SUVmax (p > 0.05). 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 BRAFV600E mutation correlated with a higher extent of the disease.

Visual and semi-quantitative analysis of 6-[18F]FDOPA PET/CT in patients with brain tumors and suspected tumor recurrence versus radionecrosis.

INTRODUCTION: Amino acid PET is a tool recommended by the main neuroimaging societies in the differential diagnosis between radionecrosis (RNC) and umour 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 SUVmax and SUVmaxlesion/SUVmaxstriatum (L/S) and SUVmaxlesion/SUVmaxcortex (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.

Impact of previous glucocorticoid therapy on diagnostic accuracy of [18F] FDG PET-CT in giant cell arteritis.

OBJECTIVE: To evaluate the impact of prior glucocorticoid (GC) treatment on the diagnostic accuracy of 18F-FDG PET-CT in giant cell arteritis (GCA). METHODS: Retrospective study of a consecutive cohort of 85 patients with proven GCA who received high-dose GC before PET-CT. RESULTS: Thirty-nine patients previously treated with methylprednisolone (MP) boluses, of whom 37% were PET-CT (uptakes grade 3 or 2) positive. The positivity rate was 80% with MP doses of 125 mg, 33% with 250 or 500 mg, and 0% with doses of 1 g.  If we also classify as positive those cases with a grade 1 uptake (with a circumferencial uptake and smooth linear or long segmental pattern, possibly indicative of "apparently inactive" vasculitis), the positivity rate increases to 62% (100%, 50-60%, and 33% for the different MP doses, respectively). In patients with new-onset GCA treated with high-dose oral GC, PET-CT positivity was 54.5% in patients treated for less than two weeks, 38.5% in those treated for 2 to 4 weeks, and 25% in those treated for 4 to 6 weeks (increasing to 91%, 77%, and 50%, respectively, if we include cases with grade 1 uptake and these characteristics). In patients with relapsing/refractory GCA, or who developed GCA having a prior history of PMR, PET-CT positivity reached 54% despite long-term treatment with low-to-moderate doses of GC (68% including cases with a grade 1 uptake). CONCLUSION: A late 18F-FDG PET-CT (beyond the first 10 days of treatment) can also be informative in a considerable percentage of cases.

Diagnosing neuroleukemiosis: Is there a role for 18F-FDG-PET/CT?

An imaging case is presented on a patient referred to our department for an 18F-FDG-PET/CT, as a paraneoplastic syndrome was suspected due to his clinical situation. He had a history of acute myeloid leukemia (AML) treated two years earlier, with sustained complete remission to date. 18F-FDG-PET/CT findings revealed hypermetabolism in almost all nerve roots, suggesting meningeal spread, consistent with the subsequent MRI findings. Cerebrospinal fluid (CSF) findings confirmed a leptomeningeal reactivation of AML. Although not many studies have evaluated the role of 18F-FDG-PET/CT in leukemia, it is a noninvasive tool for detecting extramedullary sites of disease and a good imaging alternative for those patients on whom an MRI cannot be performed.

Utility of the PET-CT in the evaluation of early response to treatment in the diffuse large B-cell lymphoma. Preliminary results.

OBJECTIVE: To assess the role of FDG-PET/CT performed after the first cycles of chemotherapy in the prediction of response to treatment in patients with diffuse large B-cell lymphoma. METHODS: Twenty patients (mean age: 48 years) were included, 16 initial staging and 4 relapse. All patients underwent PET/CT at 3 times: 1) Baseline, 2) After 1-3 cycles of chemotherapy (early response assessment), and 3) End of treatment (evaluation of final response). Early PET/CT findings were correlated to the end-treatment PET/CT and follow-up. The evaluation of the response was established according to the decrease in uptake of the lesions (SUVmax). In the early assessment, a good response indicator (GRI) was obtained when the lesion disappeared or had more than 50% reduction in SUVmax. At the end of the treatment, a complete metabolic response (CMR) was determined in negative PET scans. Follow-up was superior to 19 months and final outcome was established as progression/relapse or no evidence of disease (NED). RESULTS: At the early treatment evaluation, 16/16 patients of initial staging (100%) and 2/4 of relapse (50%) achieved GRI. At the end of treatment evaluation, 14/16 patients of initial staging with GRI achieved CMR and 1/16 PMR: 14 were alive with NED in the follow-up while 1 relapsed. In the second group, 2/2 patients with GRI achieved CMR (100%): 1 continued with NED in the follow-up and another relapsed. CONCLUSION: FDG-PET/CT after the first cycles of chemotherapy is useful to monitor treatment due to its high negative predictive value (87.5%), using it to modify treatment early in the non-responders.

[Usefulness of ventricular function values obtained using post-stress gated-SPECT in a diabetic population with clinical suspicion of ischaemic heart disease]. / Utilidad de los valores de función ventricular obtenidos mediante gated-SPECT post-estrés en población diabética con sospecha clínica de cardiopatía isquémica.

OBJECTIVE: To assess the clinical usefulness of left ventricular function values obtained using post-stress myocardial perfusion gated-SPECT in diabetic patients with suspected ischaemic heart disease (IHD). MATERIALS AND METHODS: Sixty-one patients with diabetes mellitus (DM), with clinical suspicion of IHD and no previous history of heart disease were studied. Ergometric or pharmacological post-stress myocardial perfusion gated-SPECT was performed on all patients. The relationship between the ejection fraction values and ventricular volumes, and the perfusion study results, final diagnosis, severity of the perfusion defects and the clinical evolution was studied. The mean follow-up time was 14 months. RESULTS; All the ventricular function values independently showed significant differences between the groups with a normal and pathological perfusion study, and between groups with a final diagnosis of IHD and non-IHD. After multivariate logistic regression, the end-diastolic volume (EDV) was the only value which showed a statistical association with the pathological perfusion study, its severity and the final diagnosis of IHD. No statistical association was observed between the ventricular function values and the occurrence of cardiac events. CONCLUSIONS: All the ventricular function values obtained by gated-SPECT added diagnostic information to the post-stress myocardial perfusion study in the diabetic population with suspected IHD; however, only EDV showed a statistical association with the pathological perfusion study, severity of defects and the final diagnosis of IHD.

[Value of 99mTc-labelled red cells in the detection of pulmonary haemorrhage]. / Valor de la gammagrafía con hematíes marcados con 99mTc en la detección de hemorragia pulmonar.

The use of 99mTc-labelled red cells is very extensive in the detection of haemorrhages of gastrointestinal origin. However, not only is it useful in haemorrhages in this location, but it may also be of use in other locations such as pulmonary haemorrhage. We should not forget that this is a non-invasive diagnostic method, useful in localising possible pulmonary bleeding which causes symptoms of haemoptysis, without having to resort to invasive tests such as angiography, or prior to this, to have approximate knowledge of the location of the bleeding area. We present the case of a patient with a haemoptysis picture where the use of scintigraphy with labelled red cells detected the location of the bleeding site, directing towards subsequent surgery, and a final diagnosis of haemoptysis due to pulmonary carcinoma.

[Study of physician satisfaction as a quality criterion in Nuclear Medicine]. / Estudio de satisfacción de facultativos como criterio de calidad en Medicina Nuclear.

OBJECTIVE: To determine the perception and satisfaction level of referring physicians requesting scans as final users of the Nuclear Medicine Department. MATERIAL AND METHODS: A self-administered questionnaire was designed; it was composed of 10 closed questions (5 categorised and 5 with numerical scale) and 3 open questions. The indicators evaluated were: physician's information about available tests, test indications and diagnostic information, accessibility, delay in the examination and reception of the diagnostic report, usefulness of diagnostic information and overall satisfaction with the department. Two hundred and fifteen questionnaires were sent. RESULTS: Seventy eight questionnaires were returned, so the response index was 36.3 %. The 44.6 % of physicians surveyed considered that they had sufficient information about the tests and 59.5 % were satisfied with the indications and diagnostic information. The accessibility was 7 or more out of 10 for 78.5 %. The 64.9 % of physicians considered the delay in performing examinations to be correct but the satisfaction was lower in the delay between performance and reception of the diagnostic report. The diagnostic information was considered useful by 81.9 % and relevant in the management of patients by 70.5 % of the participants surveyed. The overall satisfaction was > or = 7 out of 10 in 86.8 %. CONCLUSIONS: Overall satisfaction was high, although the level of knowledge about available tests and the delay between test performance and report reception could be improved.

[Are bone scintigraphy examinations requested in oncologic patients according to established indications?]. / Se solicitan las gammagrafías óseas en pacientes oncológicos según criterios clínicos reconocidos?

OBJECTIVE: To determine the percentage of bone scintigraphy examinations (BS) requested according to established indications and to assess the clinical impact of the scintigraphic results. MATERIAL AND METHODS: A retrospective study was performed including BS in 117 patients (70 women and 47 men) carried out in our department during the year 2001. All patients had a primary extraosseous malignancy. The correctness of the indication of each study requested was analyzed according to established criteria from the literature. BS results were classified as positive, negative, and equivocal for metastatic disease. RESULTS: 96 out of the 117 BS were performed in patients affected with the most prevalent primary malignancies: breast (57), prostate (21), and lung (18). The remaining studies were included in a miscellaneous group (gynecological [3], colorectal [4], oropharyngeal [4], and renal malignancies [4]; lymphoma [2], melanoma [2], hemangioendothelioma [1]; and cancer of the bladder [1] or pancreas [1]). Ninety-nine (85 %) of the 117 BS performed met the criteria for appropriate indication. The indication was correct in 75 % of breast, 90 % of prostate (19/21), and 100 % of lung cancers. The indication was correct in 90 % of the cases in the miscellaneous group. BS were positive in 21 patients (20 of which were confirmed). BS were equivocal in 24 patients (in 5 of whom bone metastases were confirmed). BS were negative in 72 patients (one of whom had bone metastases). The BS findings changed staging in 9 % (9/99) of the correctly indicated cases. CONCLUSION: Most BS (85 %) were indicated according to the established criteria and the clinical impact was greater in this group.

[Patient satisfaction as quality indicator in a nuclear medicine department]. / La satisfacción del usuario como indicador de calidad en un servicio de Medicina Nuclear.

OBJECTIVE: To assess patient satisfaction and dissatisfaction with a Nuclear Medicine department. MATERIAL AND METHODS: A questionnaire was designed with 9 closed questions, 1 with a numerical scale (1-10) and 1 with an open question for suggestions. The questions included different quality dimensions of the department related with waiting time for the scan, information, facilities, attention manner with department staff and global satisfaction (numerical scale, 1-10). Dissatisfaction was determined by analyzing the written complaints for the last 6 years. RESULTS: A total of 671 questionnaires were obtained, 58 % of those surveyed being women. The mean age of patients was 56.5 (+/- 16.26). The information provided was correct in 81.7 % of cases. Equipment and facilities were correct for 74.5 % of patients. Waiting list and waiting time were correct for 70 % and 66.4 % respectively. The attention manner of the department staff was the most satisfactory dimension (98.7 %). Global satisfaction was positive (> or = 7 out of 10) in 82.8 % of the patients. 29 complaints were received. Most of them were based on waiting list (12) and disagreement with assistance (9). CONCLUSIONS: Global satisfaction was high in most of patients. Waiting time was the dimension with the lowest level of satisfaction and subsidiary of improvement plans. The primary spontaneous complain by our patients was due to the waiting list.

[Clinical and prognostic value of X-ray based attenuation correction in post-stress myocardial perfusion SPECT]. / Valor clínico y pronóstico de la corrección de atenuación con rayos X en la SPECT de perfusión miocárdica post-estrés.

OBJECTIVE: The purpose of the study was to validate the X-ray-based attenuation correction technique applied to post-stress myocardial perfusion single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Fifty-six patients with clinically suspected ischemic heart disease and no history of myocardial infarction or coronary revascularization were studied. All patients underwent a myocardial perfusion SPECT after exercise (38) or pharmacological stress (18). Mean clinical follow-up time was 18.6 months. Studies were assessed after reconstruction using the filtered back projection technique and after application of the X-ray-based attenuation correction technique, and the results obtained were related to the final clinical diagnosis. RESULTS: Eleven uncorrected studies were normal, while 45 studies showed perfusion defects. After attenuation correction, absence of significant perfusion defects was observed in 24 cases (42.9 % of all cases), and ischemic heart disease was finally ruled out in 22 cases. A greater study normalization rate was seen in men (p = 0.048; odds ratio = 2,923), but this fact was not shown to be significantly correlated to the following variables: pre-test probability of ischemic heart disease, body mass index greater than 30, presence of cardiovascular risk factors or otherwise, and age. CONCLUSIONS: Application of the X-ray-based attenuation correction technique would have allowed for obviating the conduct of a resting perfusion study in 42.9 % of patients without apparently changing the diagnostic safety of the test. This fact was seen more frequently in men. This method seems to be both safe and time- and cost-effective.

[Assessment of cortical brain blood flood by brain perfusion spect in patients with a diagnosis of eating behavior disorders]. / Valoración del flujo cortical cerebral mediante SPECT de perfusión cerebral en pacientes con diagnóstico de trastornos de la conducta alimentaria.

OBJECTIVE: To evaluate cortical brain blood flow by 99mTc-HMPAO SPECT in patients with Eating Disorders (ED): restrictive anorexia (RA) and purgative bulimia (PB). MATERIAL AND METHOD: The study included 7 women with diagnostic criteria of RA and 12 with PB. The control group was made up of 12 healthy women. All subjects underwent brain 99mTc-HMPAO SPECT. The SPECT studies were quantified, yielding semiquantitative indexes relating to cerebellar activity in different regions. Body dissatisfaction was assessed by means of the BSQ (Body Shape Questionnaire). The results were analyzed with the ANOVA variance and had a statistical significance of p < 0.05. RESULTS: Mean BSQ scores were 98.28 (range 71-159) in the RA group, 145.05 (range 73-191) in the PB group, and 57.4 (range 37-88) in the control group. All patients in the sample (i.e., both RA and PB) showed global cerebral hypoperfusion versus the controls, although the difference only reached statistical significance in the RA group in the left parietal lobe (p = 0.02) and in the right (p = 0.004) and left temporal lobes (p = 0.015). In the PB group, the significantly hypoperfused regions were the right (p < 0.001) and left (p = 0.008) superior frontal lobe, the right inferior frontal lobe (p = 0.042), the right (p = 0.042) and left (p = 0.002) parietal lobes, and the right temporal lobe (p = 0.002). CONCLUSION: The results obtained showed that patients with ED had cerebral hypoperfusion compared with healthy subjects. This pattern is common in parietotemporal regions for both PB and AR although with temporal and parietal predominance in RA and PB, respectively. In addition, patients with PB had frontal region involvement.

[Myocardial perfusion SPECT with 99mTc-tetrofosmin and thoracic SPECT with Gallium-67 SPECT in a patient with chest pain and a history of sarcoidosis]. / SPECT de perfusión miocárdica con 99mTc-Tetrofosmin y SPECT torácica con Galio-67 en paciente con dolor torácico y antecedente de sarcoidosis.

We present the case of a 54-year-old male patient, with history of diagnosed sarcoidosis some years ago and myocardial involvement, who being asymptomatic, shows chest pain because of which he goes to the emergency room of the hospital. During the first hours of his admission the pain relieves with nonsteroidal antiinflammatory medication, an electrocardiogram demonstrates changes of early repolarisation with pericardial involvement, the enzymes don't rise and the echocardiogram reveals a slight pericardial effusion. The differential diagnosis is between a chest pain due to ischemia, and the secondary to myopericarditis in the clinical context of a sarcoidosis. Myocardial perfusion rest SPECT is required which is compatible with lateral acute myocardial infarction (AMI) with extension to inferior wall. A coronary angiography was carried out and showed two vessels disease (RCA and Cx), PTCA and stent were carried out successfully. During the admission a thoracic scintigraphy and SPECT with gallium -67 showed an uptake in lateral wall of left ventricle (LV). Nothing about active sarcoidosis was found.

[Radioguided occult breast lesion location (ROLL)]. / Localización radioguiada de lesiones ocultas de mama (ROLL).

OBJECTIVE: To obtain correct location of occult breast lesions by radiopharmaceutical methods. MATERIAL AND METHODS: Sixty-one patients whose ages ranged from 32 to 83 years (average: 57), with non-palpable breast lesions detected by mammography were studied. Six of them had a background of previous breast cancer. Sixty-three lesions were found. The lesions were classified into 34 clusters of microcalcifications, 25 nodules and 4 others parenchymal distortions. All patients received one dose of 0.3-0.5 mCi (11.1-18.5 MBq) of macroaggregates of 99mTc-labelled human serum albumin (99mTc-MAA) into the lesion under stereotactic mammographic or ultrasonography guidance. Anterior and lateral scintigraphic images were acquired in order to verify the correct location of the radiopharmaceutical. Intraoperative location of the lesion was performed using a gammaprobe. In case of microcalcifications, the entire removal of the lesion was verified by X-ray of the specimen. RESULTS: Placement of the radiotracer was good in 60 of 63 (95.2%) cases. Sixty-one lesions were completely removed. Pathological examination revealed 29 (47.6%) breast cancers and 32 (52.4%) benign lesions. CONCLUSION: Radioguided occult breast lesion location by radiopharmaceutical methods is a simple, safe and well-tolerated method by patients.