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Introduction/Justification: The benefits of using 18F-FDG PET/CT for staging and managing treatment in patients with multiple myeloma (MM) are extensively documented. Recent studies indicate that 68Ga-PSMA PET/CT is also an excellent marker for MM lesions and may complement 18F-FDG due to the significant genetic heterogeneity observed in these patients' lesions. The involvement of bone tissue stands out as one of the most critical aspects of MM. To quantify this involvement, two quantitative parameters have recently been proposed: Percentage of Bone Involvement (PBI) and Intensity of Bone Involvement (IBI). Objectives: This study aims to compare PBI and IBI in 68Ga-PSMA and 18F-FDG PET/CT images for multiple myeloma patients. Materials and Methods: Fifteen patients were included in the study, 8 men (53.3%), with a mean age of 66.7 ± 10.7 years. The patients underwent 68Ga-PSMA and 18F-FDG PET/CT scans with a maximum interval of 8 days between images (median 4 days). The bone tissue was segmented in the images based on the Hounsfield scale of the CT image, followed by processing for closing of the volume of interest (VOI). Both PBI and IBI were calculated for the two radiotracers, with the liver SUV used as a reference for 18F-FDG and the left atrium as a reference for 68Ga-PSMA. Spearman's rank-order correlation assessed the relationship between PBI and IBI data. Results: On average, PBI values were higher for 68Ga-PSMA than for FDG, at 3.07% ± 2.5% and 1.96% ± 3.8%, respectively. The mean IBI values were similar for both radiotracers: 0.08 ± 0.13 for 18F-FDG and 0.08 ± 0.09 for 68Ga-PSMA. The median IBI calculated for 68Ga-PSMA was 0.05, higher than the 0.01 found for 18F-FDG. Despite the similarity in average values between 68Ga-PSMA and 18F-FDG, the maximum PBI and IBI values were found in different patients for both radiotracers. Additionally, the Spearman test did not indicate correlation between the variables: (r = 0.39; p = 0.16) for PBI and (r = 0.41; p = 0.13) for IBI. Conclusion: The average and maximum values of PBI and IBI for 68Ga-PSMA and 18F-FDG are close. However, no correlation was found between them, highlighting that the heterogeneous genetic profile of the disease results in different uptake patterns for both radiotracers.

Introduction/Justification: Static renal scintigraphy using 99mTc-DMSA is an accurate method for diagnosing and monitoring renal scars and allows for semi-quantification of relative tubular function (RTF). However, in cases of hydronephrosis, radiopharmaceutical accumulation in the pyelocaliceal system may interfere with RTF quantification. Although 24-hour images are typically requested to address this issue, they can inconvenience patients and disrupt the nuclear medicine service routine. Objectives: This study aimed to assess the impact of additional 24-hour imaging on RTF quantification in patients with hydronephrosis compared to standard 3-hour images. Materials and Methods: A retrospective analysis was conducted on patients who underwent renal scintigraphy with 99mTc-DMSA, focusing on those who received additional 24-hour imaging. Patients were divided into two groups: those aged up to 12 years (Group 1) and those over 12 years old (Group 2). Planar images were acquired 3 hours post-injection of 175 mBq of 99mTc-DMSA for adults and 1.5 MBq/kg for patients weighing up to 40 kg. Additional delayed images were obtained after 24 hours if pyelocaliceal dilation was present. RTF was calculated using both 3-hour and 24-hour images, preferably using semi-automatic regions of interest. The T-Student test was utilized for statistical analysis, considering a difference of ≤ 3% between the two values as not significantly justifying the additional 24-hour image. Results: A total of 1,205 consecutive 99mTc-DMSA scans from February 2019 to December 2023 were evaluated. Group 1 comprised 662 patients, with 62 undergoing additional 24-hour imaging, while Group 2 consisted of 543 patients, with 43 undergoing 24-hour imaging. The mean value of the difference between the 3h and 24h images is 1.95% ± 1.83% and median 2 (0 - 6) for Group 1, and 2.40% ± 2.08% and median 2 (0 - 8) for Group 2. Statistical analysis demonstrated equivalence between RTF quantifications obtained at 3-hour and 24-hour imaging for Group 1 p < 0.0001, 95% confidence interval (1.45 - 2.42). However, for Group 2, quantifications at 3-hour and 24-hour imaging were not necessarily equivalent p = 0.0714, 95% confidence interval (1.76 - 3.05). Conclusion: Additional 24-hour imaging with 99mTc-DMSA in patients under 12 years of age with pyelocaliceal dilation does not appear to impact RTF compared to 3-hour images. However, for older patients, 24-hour imaging is necessary for greater accuracy in RTF determination. Further investigations are warranted to better understand factors influencing RTF calculation, guiding the indication for additional 24-hour imaging.

Introduction/Justification: Antisynthetase syndrome is an autoimmune pathology characterized by production of autoantibodies against aminoacyl tRNA synthetase, mainly anti-Jo-1. Report: Male patient presenting a clinical picture of polyarthritis in hands and wrists, periorbital edema, myositis and interstitial lung disease. FAN 1/320 (nuclear homogeneous), reactive anti Jo-1, elevated CPK, erythrocyte sedimentation rate and CRP. MRI presenting muscle edema, electroneuromyography compatible with myopathy and chest CT scan suggesting inflammatory/infectious pattern. Patient was diagnosed with antisynthetase syndrome and prednisone introduced. Later on course cyclophosphamide was added due to lung involvement. He evolved with respiratory and joint symptom improvement but with progressive worsening of muscle symptoms, characterized by proximal weakness (difficulty getting out of bed and car, daily life activities like brushing his teeths and eating). He also presented CPK rise, persistent subfebrile temperature and signs of inflammatory activity (leukocytosis and CRP rise), without any apparent focus and isolated episodes of dysphagia. Rituximabe was introduced and PET/CT scan was performed to search for the focus of the infection. PET/CT showed a diffuse pattern of muscle hypermetabolism, specially in right lower limb, suggesting a diffuse muscle inflammation without any infectious focus. Conclusion: Antisynthetase syndrome is a rare entity with few PET/CT reports in the literature. However PET scan appears to be very useful in the investigation of fever of unknown origin, diagnosing inflammatory activity and in response assessment evaluation.

Introduction/Justification: Anorectal melanoma is a rare tumor that develops in melanin producing pigment cells of the anus and rectum. As a rare entity there is not much literature regarding the management of this pathology. It`s a difficult diagnosis and the majority of patients present metastases. Therefore we presented a case of probable anorectal melanoma submitted to 18F-FDG PET/CT. Report: 76 years old, male with history of anal pain and sporadic bleeding after bowel movement in the last 6 months. Bowel habits of 3-4 times daily and weight loss not quantified in the period. Digital rectal examination revealed a vegetative, friable and painful lesion, found 1 cm from anal verge, in the anterior wall, extending for 3 cm and presence of blood. Colonoscopy revealed an infiltrative, multilobular, friable and non stenosing lesion, measuring 5 cm and including pectineal line and anterior wall of the anus. Biopsy revealed colorectal mucosa with atypical cellular proliferation and ulceration and immunohistochemistry demonstrated markers that confirmed the diagnosis of melanoma (primary lesion or metastatic). Chest and abdominal CT scans demonstrated lung, liver and left adrenal lesions. 18F- FDG PET/CT was performed for primary staging. PET scan revealed hypermetabolism in anorectal wall thickening, that might be the primary lesion and in multiple hypermetabolic lesions in thyroid, lungs, liver, left adrenal, stomach lesser curvature, retroperitoneal and pelvic nodes, peritoneal implants and bones, suggesting metastatic involvement. Conclusion: This report shows a patient with a clinical picture, physical examination and complementary exams compatible with anorectal neoplasia. Immunohistochemistry confirms the diagnosis of melanoma. Anorectal melanomas are extremely rare and aggressive. Lymphatic dissemination of anal melanomas results in distant metastases to the liver and lungs by up to 90% of cases. These findings are in line with the FDG PET/CT reported in our study. 18F-FDG PET/CT may be useful in the primary staging of anal melanoma patients and in identifying lesions missed by other conventional radiological methods.

Introduction: Subtraction of ictal-interictal SPECT co-registered to MRI (SISCOM) is a quantification tool that can improve the sensitivity and specificity of the epileptogenic zone (EZ) localization. Commercially available image analysis software packages for SISCOM are costly, and Statistical Parametric Mapping (SPM) could be an alternative free software for the definition of the EZ. There are only a few studies that compare SISCOM using SPM (SISCOM-SPM) with visual analysis.Aim: To compare SISCOM-SPM vs. visual analysis for localization of the EZ in patients with pharmacoresistant focal epilepsies.Materials and methods: We evaluated all our patients with focal epilepsies that underwent ictal and interictal SPECT. We defined the reference standard to locate the EZ by pathology and follow-up (in patients submitted to surgery), or seizure semiology, serial EEG, long-term video-EEG, 18F-FDG PET/CT, and MRI (in patients who were not operated). We compared the location of the EZ by visual analysis of SPECT images and by SISCOM-SPM to the reference standard and classified as concordant, discordant, or partially concordant.Results: We included 23 patients. Visual analysis was concordant with the EZ reference standard in only 13 patients (56.5%), while SISCOM-SPM was concordant in 18 cases (78.3%), providing a 21.8% increase in the location of EZ. However, this difference was not significant due to the small sample size (p = 0.0856).Conclusion: Our preliminary results demonstrate that, in clinical practice, SISCOM-SPM has the potential to add information that might help localize the EZ compared to visual analysis. SISCOM-SPM has a lower cost than other commercially available SISCOM software packages, which is an advantage for developing countries. Studies with more patients are necessary to confirm our findings.

Introdução: Este trabalho consistiu no desenvolvimento de um dispositivo de baixo custo para testes e protocolos de exames de medicina nuclear in vitro. Foi desenvolvido e validado inicialmente para medir a taxa de filtração glomerular (TFG) com EDTA-51Cr usando apenas uma câmera de cintilação. O dispositivo consiste de 5 cilindros de chumbo (com tampas) fixados perpendicularmente e espaçadamente sobre uma placa de chumbo, que ao ser acoplado na câmara de cintilação torna-se equivalente a um contador-gama tipo poço, com sensibilidade de 300Bq. Esse dispositivo foi testado para as quantidades usuais de EDTA-51Cr das amostras de plasma sanguíneo de 8 pacientes (6 homens, 2 mulheres, idades de 43-68 anos, média 54 anos) que fizeram o exame de modo convencional. Resultados: Os valores de TFG obtidos com o método convencional e com o dispositivo variaram respectivamente, de 27 a 73 ml/min/1,73m2 (média 56,7±14,0) e de 31 a 82 ml/min/1,73m2 (média 60,9±14,5), expressando uma correlação de r=0,9010 e p=0,5628 (95% de confiança). Conclusão: O dispositivo proposto é uma alternativa confiável ao uso do “Contador Gama Tipo Poço” convencional para medir a TFG usando o método EDTA-51Cr. Devido ao seu custo muito baixo, tem o potencial de promover o uso deste procedimento em qualquer serviço de medicina nuclear que possua uma câmera de cintilação. Esta tecnologia foi depositada no Instituto Nacional de Propriedade Industrial (INPI) sob o processo de patente BR:10.2015.020347-0.

Introduction: To perform a head-to-head comparison of the uptake pattern of F-18 fluorodeoxyglucose in positron emission computed tomography (FDG PET/CT) in radioiodine refractory thyroid carcinomas (RAIR) in the same patient under elevated TSH levels (eTSH) and suppressed TSH levels (sTSH). Methods: FDG PET/CT studies were performed under two conditions: levothyroxine intake (sTSH) and 30 days after hormonal withdrawal (eTSH). SUVmax values and the number of lesions detected (local recurrence and metastases in cervical and distant lymph nodes, lungs and bone) where blindly evaluated. Blood serum TSH and Tg levels were obtained prior to both studies. FDG PET/CT imaging, neck ultrasound, biopsy and follow-up were considered the reference standard. Results: Fifteen patients performed both eTSH and sTSH FDG PET/CT studies. Both were positive for metastases in 80% of the patients. eTSH FDG PET/CT studies did not reveal increased uptake (p = 0.0640) and did not demonstrate a higher number of lesions (p = 0.320) when compared to sTSH FDG PET/CT studies. There was no change in the clinical management of these patients. Conclusions: eTSH FDG PET/CT in patients with RAIR did not show more metastases in comparison to sTSH FDG PET/CT and there was no impact in clinical management of patients. Elevating TSH levels (whether by hormonal withdrawal or recombinant TSH) in patients being submitted to FDG PET/CT may not be necessary.

Background: Studies have shown significant benefits of exercise therapy in heart failure (HF) with a reduced ejection fraction (HFrEF) and HF with a preserved ejection fraction (HFpEF). The mechanisms responsible for the beneficial effect of exercise in HFrEF and HFpEF are still unclear. We hypothesized that the effect of exercise on myocardial remodeling may explain its beneficial effect. Methods: IMAGING-REHAB-HF is a single-center, randomized, controlled clinical trial using cardiac magnetic resonance imaging, vasomotor endothelial function, cardiac sympathetic activity imaging and serum biomarkers to compare the effect of exercise therapy in HFpEF (LVEF ≥ 45%) and HFrEF (LVEF < 45%). Subjects will be assessed at baseline and after 4 months. The exercise program will consist of three 60-min exercise sessions/week. The primary endpoints are the effect of exercise on myocardial extracellular volume (ECV), left ventricular (LV) systolic function, LV mass, LV mass-to-volume and LV cardiomyocyte volume. Secondary endpoints include the effect of exercise on vasomotor endothelial function, cardiac sympathetic activity and plasmatic biomarkers. Patients will be allocated in a 2:1 fashion to supervised exercise program or usual care. A total sample size of 90 patients, divided into two groups according to LVEF:HFpEF group (45 patients:30 in the intervention arm and 15 in the control arm) and HFrEF group (45 patients:30 in the intervention arm and 15 in the control arm) – will be necessary to achieve adequate power. Conclusion: This will be the first study to evaluate the benefits of a rehabilitation program on cardiac remodeling in HF patients. The unique design of our study may provide unique data to further elucidate the mechanisms involved in reverse cardiac remodeling after exercise in HFpEF and HFrEF patients.

AimsTo assess the validity of an online method to quantitatively evaluate cerebral hypometabolism in patients with pharmacoresistant focal epilepsy as a complement to the visual analysis of the 18F-FDG positron emission tomography (PET)/CT exam.MethodsA total of 39 patients with pharmacoresistant epilepsy and probable focal cortical dysplasia [22 patients with frontal lobe epilepsy (FLE) and 17 with temporal lobe epilepsy (TLE)] underwent a presurgical evaluation including EEG, video-EEG, MRI, and 18F-FDG PET/CT. We conducted the automated quantification of their 18F-FDG PET/CT data and compared the results with those of the visual-PET analysis conducted by experienced nuclear medicine physicians. For each patient group, we calculated Cohen’s Kappa coefficient for the visual and quantitative analyses, as well as each method’s sensitivity, specificity, and positive and negative predictive values.ResultsFor the TLE group, both the visual and quantitative analyses showed high agreement. Thus, although the quantitative analysis could be used as a complement, the visual analysis on its own was consistent and precise. For the FLE group, on the other hand, the visual analysis categorized almost half of the cases as normal, revealing very low agreement. For those patients, the quantitative analysis proved critical to identify the focal hypometabolism characteristic of the epileptogenic zone. Our results suggest that the quantitative analysis of 18F-FDG PET/CT data is critical for patients with extratemporal epilepsies, and especially those with subtle MRI findings. Furthermore, it can easily be used during the routine clinical evaluation of 18F-FDG PET/CT exams.SignificanceOur results show that quantification of 18F-FDG PET is an informative complementary method that can be added to the routine visual evaluation of patients with subtle lesions, particularly those in the frontal lobes.

Objective: To evaluate the stage of maturation and the metabolism of neurogenic heterotopic ossification by using SPECT/CT. Methods: A total of 12 medical records of patients with spinal cord injury, all of them classified according to the ASIA protocol (disability scale from the American Spinal Injury Association) in complete lesion (A) and partial lesions (B, C and D) and registered at the Laboratory of Biomechanics and Rehabilitation of the Locomotor System, were submitted to SPECT/CT evaluation. Results: Sixteen hips with heterotopic ossification observed in X-ray were studied and only two (12.5%) had high osteoblastic activity. Five hips showed medium activity, three (18.75%) low activity and six (37.5%) did not present any activity detected by SPECT/CT. Conclusion: SPECT/CT helps to determinate which patients have a greater risk of relapse after surgical resection, proving to be a useful imaging study in preoperative evaluation that can be used to determinate the postoperative prognosis of these patients. Level of Evidence III, Investigating a Diagnostic Test.

PURPOSE: Create and validate a proposed animal model for training in sentinel lymph node biopsy of the stomach. METHODS: In thirty-two rabbits, through a laparotomy, they received a subserosal injection of 0.1 ml of phytate labeled with technetium-99m (0.2 mCi) in the anterior wall of the gastric corpus, followed by 0.2 ml of Blue Patent V® 2.5%, through the same puncture site. Suspicious lymph nodes were searched in vivo at five, ten and 20 minutes, both visually (Blue Patent stained lymph nodes) and with a manual gamma radiation detector (to detect suspected radioactive lymph nodes). After 20 minutes, was performed resection of these for further evaluation of radioactivity (ex vivo) and histological study. RESULTS: Lymph nodes were identified in 30 rabbits (Average of 2.2 lymph nodes per animal). Of the 90 suspected lymph nodes that occurred in the study, 70 cases (77.8%) were histologically confirmed for lymphoid tissue. Of these, the majority were located in the periesophageal region of the gastric fundus. The sample presented a mortality rate of 6.25% and nine complications related to the method, which interfered in the identification of the lymph nodes. CONCLUSION: The animal model for sentinel node biopsy in rabbit stomachs proved to be feasible, with low complexity and reproduced the difficulties encountered for gastric lymph node biopsy in humans, being adequate for surgical training.OBJETIVO: Criar e validar uma proposta de modelo animal para o treinamento em pesquisa de linfonodos sentinelas no estômago. MÉTODOS: Em trinta e dois coelhos, mediante laparotomia, foi injetado na subserosa da parede anterior do corpo gástrico, 0,1 ml de fitato marcado com tecnécio-99m (0,2 mCi), seguido pelo mesmo orifício, de 0,2 ml de Azul Patente V® 2,5%. A cavidade abdominal foi avaliada, in vivo, por meio de inspeção para pesquisa de suspeitas de linfonodos azuis e com detector manual de radiação gamma aos cinco, dez e 20 minutos para pesquisa de suspeitas de linfonodos radioativas. Após 20 minutos, foi realizada a ressecção dessas para posterior avaliação da radioactividade (ex vivo) e estudo histológico. RESULTADOS: Foram identificados linfonodos em 30 coelhos (Média de 2,2 linfonodos por animal). Das 90 suspeitas de linfonodos ocorridas no estudo, em 70 casos (77,8%) obteve-se confirmação histológica para tecido linfóide. Destas, a maioria estava localizada na região periesofágica do fundo gástrico. A amostra apresentou taxa de mortalidade de 6,25% e nove intercorrências relacionadas ao método, que interferiram na identificação dos linfonodos. CONCLUSÃO: O modelo animal para pesquisa de linfonodos sentinelas em estômago de coelhos mostrou-se factível, pouco complexo e reproduziu as dificuldades encontradas para a pesquisa de linfonodos gástricos em humanos, sendo adequado para o treinamento cirúrgico.

OBJECTIVE: Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES). METHOD: It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS: There was a significant statistical difference between the two groups related to patient's ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION: FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

OBJECTIVE: To compare the accuracy of SPM and visual analysis of brain SPECT in patients with mesial temporal lobe epilepsy (MTLE). METHOD: Interictal and ictal SPECTs of 22 patients with MTLE were performed. Visual analysis were performed in interictal (VISUAL(inter)) and ictal (VISUAL(ictal/inter)) studies. SPM analysis consisted of comparing interictal (SPM(inter)) and ictal SPECTs (SPM(ictal)) of each patient to control group and by comparing perfusion of temporal lobes in ictal and interictal studies among themselves (SPM(ictal/inter)). RESULTS: For detection of the epileptogenic focus, the sensitivities were as follows: VISUAL(inter)=68%; VISUAL(ictal/inter)=100%; SPM(inter)=45%; SPM(ictal)=64% and SPM(ictal/inter)=77%. SPM was able to detect more areas of hyperperfusion and hypoperfusion. CONCLUSION: SPM did not improve the sensitivity to detect epileptogenic focus. However, SPM detected different regions of hypoperfusion and hyperperfusion and is therefore a helpful tool for better understand pathophysiology of seizures in MTLE.OBJETIVO: Comparar a acurácia do SPM com a análise visual na detecção do foco epileptogênico e alterações perfusionais à distância no SPECT cerebral. MÉTODO: Foram realizados os SPECTs ictal e interictal de 22 pacientes com epilepsia de lobo temporal mesial (ELTM). A análise visual foi realizada nos estudos interictal (VISUAL(inter)) e ictal (VISUAL(ictal/inter)). Na análise com SPM foi comparado o estudo interictal (SPM(inter)) e ictal (SPM(ictal)) de cada paciente com o grupo controle e comparou-se a perfusão dos lobos temporais entre os estudos ictal e interictal (SPM(ictal/inter)). RESULTADOS: Para a detecção do foco epileptogênico, as sensibilidades foram as seguintes: VISUAL(inter)=68%; VISUAL(ictal/inter)=100%; SPM(inter)=45%; SPM(ictal)=64% and SPM(ictal/inter)=77%. O SPM foi capaz de detectar mais áreas de hiperperfusão e hipoperfusão. CONCLUSÃO: O SPM não aumentou a sensibilidade na detecção do foco epileptogênico. Entretanto, o SPM detectou diferentes regiões de hipoperfusão e hiperperfusão e portanto, ele pode ser uma ferramenta de ajuda para se melhor entender a patofisiologia das crises na ELTM.

A 26 year-old female was admitted with abdominal pain, fever and weight loss. The clinical and laboratory investigations led to the diagnosis of paracoccidioidomycosis. Gallium-67 whole body images correlated well with the clinical course of the disease and with the patient's prognosis.Paciente do sexo feminino de 26 anos foi internada com dor abdominal, febre e emagrecimento. A investigação clínico-laboratorial estabeleceu o diagnóstico de paracoccidioidomicose. Os achados cintilográficos com citrato de gálio-67 correlacionaram-se com o curso clínico da paciente.

Objective. To create a ureteral obstruction experimental model that can be proved through Tc99m-DTPA renal scintigraphy and histopathological studies, without causing total renal function loss. Materials and Methods. Ten New Zealand white rabbits were submitted to a surgical experiment to create a model of unilateral obstruction to urinary flow. Surgery procedure provided unilateral ureteral obstruction (left kidney) to urinary flow and posteriorly was evaluated by Tc99m-DTPA renal scintigraphy and histopathological study. Tc99m-DTPA renal study was performed to detect and quantify signs of obstruction and to evaluate renal function. Statistical analysis was performed through the Student t-test with a significance level of P

CONTEXT: Thyroid uptake and scintigraphy using 99mTc-pertechnetate has proven to be more advantageous than with 131I-iodide, since the images have better quality, the procedure is faster and the patient is submitted to a lower radiation dose. OBJECTIVE: The purpose of this study was to standardize a simple and fast methodology for performing thyroid uptake and scintigraphy and to determine the normal values for 99mTc- pertechnetate uptake. TYPE OF STUDY: Prospective, non-randomized. SETTING: Division of Nuclear Medicine, Department of Radiology, School of Medical Sciences, Campinas State University. PARTICIPANTS: The study consisted of 47 normal individuals, 30 women and 17 men, with ages ranging from 19 to 61 years (mean of 33 years). PROCEDURES: The laboratory assessment of thyroid function consisted of serum dosages of ultra-sensitive thyroxin and thyrotrophin. Twenty minutes after an intravenous injection of 10 mCi (370 MBq) of 99mTc-pertechnetate, the images were obtained on a computerized scintillation camera equipped with a low-energy high-resolution parallel hole collimator. RESULTS: All the individuals were euthyroid both on clinical and laboratory evaluation. The baseline thyroid 99mTc-pertechnetate uptake ranged from 0.4 to 1.7%. The uptake values obtained in these normal individuals showed that 95% presented a thyroid uptake that ranged from 0.4 to 1.5% of the injected dose. CONCLUSION: The assessment of thyroid structure and function using 99mTc-pertechnetate is a simple, fast and efficient method, which could easily become a part of the routine studies in nuclear medicine laboratories.

CONTEXT AND OBJECTIVE: The diagnosis of repetitive strain injury (RSI) is subjective and solely based on clinical signs and physical examination. The aim of this paper was to assess the usefulness of three-phase bone scintigraphy (TPBS) in diagnosing RSI. DESIGN AND SETTING: Prospective study at the Division of Nuclear Medicine, Department of Radiology, School of Medical Sciences, Universidade Estadual de Campinas (Unicamp). METHODS: Seventy-three patients (mean age 31.2 years; 47 males) with clinical suspicion of RSI in the upper limbs were studied. A total of 127 joints with suspicion of RSI were studied. The shoulders, elbows and wrists were analyzed semi-quantitatively, using the shafts of the humeri and ulnae as references. The results were compared with a control group of 40 normal individuals. The patients’ signs and symptoms were used as the "gold standard" for calculating the probabilities. RESULTS: From visual analysis, abnormalities were observed in the flow phase for four joints, in the blood pool phase for 11 joints and in the delayed images for 26 joints. Visual analysis of the joints of the control group did not show any abnormalities. Semi-quantitative analysis showed that most of the patients’ joint ratios were normal. The exceptions were the wrists of patients with left-sided RSI (p = 0.0216). However, the sensitivity (9%) and accuracy (41%) were very low. CONCLUSION: TPBS with semi-quantitative analysis has very low sensitivity and accuracy in the detection of RSI abnormalities in the upper limbs.

CONTEXT: More than 50% of patients with prostate, breast or lung cancer will develop painful bone metastases. The purpose of treating bone metastases is to relieve pain, reduce the use of steroids and to maintain motion. OBJECTIVE: To evaluate the use of samarium-153-EDTMP (153Sm-EDTMP) for the treatment of bone pain secondary to metastases that is refractory to clinical management. TYPE OF STUDY: Retrospective. SETTING: Division of Nuclear Medicine, Universidade Estadual de Campinas (Unicamp). METHODS: Fifty-eight patients were studied (34 males) with mean age 62 years; 31 patients had prostate cancer, 20 had breast cancer, three had lung cancer, one had lung hemangioendothelioma, one had parathyroid adenocarcinoma, one had osteosarcoma and one had an unknown primary tumor. All patients had multiple bone metastases demonstrated by bone scintigraphy using 99mTc-MDP,and were treated with 153Sm-EDTMP. Response to treatment was graded as good (pain reduction of 50-100%), intermediate (25-49%) and poor (0-24%). RESULTS: All patients showed good uptake of 153Sm-EDTMP by bone metastases. Among the patients with prostate cancer, intermediate or good response to therapy occurred in 80.6% (25 patients) and poor response in 19.4% (6). Among the patients with breast cancer, 85% (17) showed intermediate or good response to therapy while 15% (3) showed poor response. All three patients with lung cancer showed poor response to treatment. The lung hemangioendothelioma and unknown primary lesion patients showed intermediate response to treatment; the osteosarcoma and parathyroid adenocarcinoma patients showed good response to treatment. No significant myelotoxicity occurred. DISCUSSION: Pain control is important for improving the quality of life of patients with advanced cancers. The mechanism by which pain is relieved with the use of radionuclides is still not yet completely understood, however, the treatment is simple and provides a low risk of mielotoxicity. CONCLUSION: Treatment with 153Sm-EDTMP can control the pain secondary to bone metastases effectively in most patients with breast and prostate cancer without significant side effects.

CONTEXT AND OBJECTIVE: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc-DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. DESIGN AND SETTING: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. METHODS: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. RESULTS: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). CONCLUSION: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use.

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