68Ga-DOTATATE PET/CT versus 111In-octreotide scintigraphy in patients with neuroendocrine tumors: a prospective study / PET/CT com 68Ga-DOTATATE versus cintilografia com 111In-octreotide em pacientes com tumores neuroendócrinos: estudo prospectivo

Abstract Objective: To compare 68Ga-DOTA-DPhe1,Tyr3-octreotate (68Ga-DOTATATE) positron-emission tomography/computed tomography (PET/CT) findings with those of conventional 111In-octreotide scintigraphy in patients with neuroendocrine tumors (NETs). Materials and Methods: This was a single-center prospective study including 41 patients (25 males; mean age, 55.4 years) with biopsy-proven NETs who underwent whole-body 111In-octreotide scintigraphy and whole-body 68Ga-DOTATATE PET/CT. The patients had been referred for tumor staging (34.1%), tumor restaging (61.0%), or response evaluation (4.9%). Images were compared in a patient-by-patient analysis to identify additional lesions, and we attempted to determine the impact that discordant findings had on treatment planning. Results: Compared with 111In-octreotide scintigraphy, 68Ga-DOTATATE PET/CT revealed more lesions, the additional lesions typically being in the liver or bowel. Changes in management owing to the additional information provided by 68Ga-DOTATATE PET/CT occurred in five patients (12.2%), including intermodal changes in three (7.3%) and intramodal changes in two (4.9%). In addition, 68Ga-DOTATATE PET/CT yielded incidental findings unrelated to the primary NET in three patients (7.3%): Hürthle cell carcinoma of the thyroid, bowel non-Hodgkin lymphoma, and a suspicious breast lesion. Conclusion: We conclude that 68Ga-DOTATATE PET/CT is superior to conventional 111In-octreotide scintigraphy for the management of NETs because of its ability to determine the extent of the disease more accurately, which, in some cases, translates to changes in the treatment plan.

RESUMO Objetivo: Comparar os achados da PET/CT com 68Ga-DOTATATE em relação aos da cintilografia com 111In-octreotide em pacientes com tumores neuroendócrinos (TNEs). Materiais e Métodos: Estudo prospectivo unicêntrico incluindo 41 pacientes (25 homens; média de idade: 55,4 anos) com TNEs comprovados por biópsia submetidos a cintilografia de corpo inteiro com 111In-octreotide e PET/CT com 68Ga-DOTATATE. Os pacientes incluídos foram encaminhados para estadiamento do tumor (34,1%), reestadiamento (61,0%) ou avaliação da resposta (4,9%). As imagens foram comparadas para identificar lesões adicionais e o impacto dos achados discordantes no planejamento terapêutico. Resultados: Na comparação com a cintilografia com 111In-octreotide, a PET/CT com 68Ga-DOTATATE revelou mais lesões, mais frequentemente localizadas no fígado e intestino. Mudanças no tratamento devidas às informações adicionais reveladas pela PET/ CT ocorreram em 5/41 pacientes (12,2%), incluindo mudanças intermodalidade em três casos (7,3%) e intramodalidade em dois casos (4,9%). A PET/CT também identificou achados incidentais não relacionados ao TNE em 3/41 pacientes (7,3%), incluindo um carcinoma de células de Hürthle da tireoide, um linfoma não Hodgkin de intestino e uma lesão mamária suspeita. Conclusão: A PET/CT com 68Ga-DOTATATE é superior à cintilografia convencional com 111In-octreotide para o manejo de pacientes com TNEs, em virtude da sua capacidade de detectar a extensão da doença com mais precisão, o que se traduz, em alguns casos, em alterações terapêuticas.

Prognostic role of 18F-FDG PET-CT in the prone position in the evaluation of invasive breast carcinoma

Introduction: The objective of this study was to correlate the features of invasive breast carcinoma in 18F-FDG positron emission tomography/computed tomography with histopathological results, findings from other imaging methods, and survival. Methods: This observational single-center study included patients who underwent staging 18F-FDG positron emission tomography/ computed tomography between September 2012 and April 2019; the results were correlated with the findings of other imaging tests and anatomopathological results. Lesions were evaluated for their maximum standardized uptake value on positron emission tomography/computed tomography performed in the prone position. Tumors were classified into three subtypes (luminal, HER2 and triple-negative) based on immunohistochemical analyses. Results: A total of 125 patients with a mean age of 52 years (24­90 years) were analyzed. The primary tumor showed an increased 18F-FDG concentration on positron emission tomography/computed tomography in 122 (97.6%) patients, with a mean maximum standardized uptake value of 7.15 (1.0­32.9 range). The mean maximum standardized uptake value was higher in the triple-negative subtype (11.4; n=24) than in the luminal (6.2; n=89) and HER2 (5.0; n=9) subtypes (p<0.01). Tumors with more aggressive histological and immunohistochemical characteristics showed higher maximum standardized uptake values. Patients with a standardized uptake value greater than 7 in the primary tumor or greater than 6.7 in the axillary lymph nodes had poor overall survival (p=0.03 and p<0.01, respectively). Conclusions: Our study suggests that the maximum standardized uptake value obtained on positron emission tomography/computed tomography in the prone position may correlate with the tumor immunophenotype and overall survival regardless of the treatments performed, and can be used as a prognostic biomarker in invasive breast carcinoma patients

Recurrent diffuse large B-cell lymphoma mimicking primary breast cancer

Breast lymphoma can represent 0.8%­2.2% of extranodal lymphomas and 0.1%­0.5% of primary breast neoplasms. Imaging findings are not specific, and its distinction from primary invasive breast carcinoma should be based on clinical data and histopathological analysis. We present the case of a 62-year-old woman who showed an unusual pattern of recurrent diffuse large B-cell lymphoma (DLBCL) mimicking primary breast cancer on imaging studies, including mammography, ultrasound, magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT).

18F-FDG PET/CT helps to find occult carcinoma in a patient with multiple breast masses at magnetic resonance imaging / PET/CT com 18F-FDG ajuda a identificar carcinoma oculto em paciente com múltiplos nódulos mamários na ressonância magnética

52-year-old female patient with diagnosis of invasive carcinoma in the left breast and metastatic lymph node in the right axilla. Magnetic resonance imaging showed multiple breast masses, with four previous negative biopsies in the right breast. 18F-FDG positron emission tomography (PET)/computed tomography (CT) was performed in prone position, dedicated to breast evaluation. It showed increased uptake in a mass in the right breast. After PET/magnetic resonance imaging (MRI) fusion and second-look breast ultrasound, this mass was submitted to percutaneous biopsy, which confirmed a second invasive breast carcinoma and changed patients' treatment. This is an example of how PET/MRI dedicated devices can improve the evaluation of selected breast lesions.

Paciente do sexo feminino, de 52 anos, com diagnóstico de carcinoma invasivo na mama esquerda e linfonodo metastático na axila direita. A ressonância magnética mostrou múltiplos nódulos mamários bilaterais, com quatro biópsias anteriores negativas na mama direita. 18F-FDG PET/tomografia computadorizada (CT) foi realizado em decúbito ventral, dedicada à avaliação das mamas, demonstrou aumento da captação em um nódulo na mama direita. Depois de fusão das imagens do PET/CT com a ressonância magnética (RM) e ultrassonografia direcionada, esta lesão foi submetida à biópsia percutânea, que confirmou um segundo carcinoma invasivo na mama direita, alterando o tratamento. Este é um exemplo de como os dispositivos dedicados de PET/RM podem melhorar a avaliação das lesões mamárias selecionadas.

Computed tomography-guided preoperative localization of musculoskeletal lesions using the ROLL technique / Localização pré-operatória guiada por tomografia computadorizada de lesões musculoesqueléticas utilizando a técnica ROLL

Abstract Objective: To describe the preoperative localization of musculoskeletal lesions with the radioguided occult lesion localization (ROLL) technique. Materials and Methods: In all cases, computed tomography-guided injection of technetium-99m sulfur colloid was performed, directly into or near the suspicious lesion, up to 36 hours before the surgical procedure. Lesions were detected intraoperatively with a gamma probe. Results: We report the cases of six patients submitted to radioguided surgery, including three patients with bone lesions suspicious for metastasis, two patients suspected of recurrent sarcoma, and one patient with no previous diagnosis who had a nodular lesion on the left leg. Patients tolerated the procedure well, and no complications were associated with the puncture. All marked lesions were easily identified intraoperatively and were excised with clear margins. Conclusion: The ROLL technique was effective in the intraoperative localization of occult musculoskeletal lesions, demonstrating that it is a feasible and promising technique for the surgical exploration of selected cases.

Resumo Objetivo: Descrever a localização pré-operatória de lesões musculoesqueléticas utilizando a técnica radioguided occult lesion localization (ROLL). Materiais e Métodos: Em todos os casos foi realizada administração guiada por tomografia computadorizada de enxofre coloidal marcado com tecnécio-99m, diretamente no interior ou adjacente à lesão suspeita, até 36 horas antes do procedimento cirúrgico. As lesões foram localizadas no intraoperatório utilizando um gama-probe. Resultados: São descritos seis casos de pacientes submetidos a cirurgia radioguiada, sendo três pacientes com lesões ósseas suspeitas para metástase, dois pacientes com sarcoma recidivado e um paciente com lesão nodular na perna esquerda sem diagnóstico prévio. Os pacientes toleraram bem o procedimento e não ocorreram complicações. Todas as lesões foram identificadas adequadamente no intraoperatório e ressecadas com margens livres. Conclusão: A técnica ROLL foi efetiva na localização intraoperatória de lesões musculoesqueléticas ocultas, demonstrando que este procedimento é factível e promissor para facilitar a exploração cirúrgica em casos selecionados.

Detection of distant metastases in patients with locally advanced breast cancer: role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography and conventional imaging with computed tomography scans / Detecção de metástases a distância em pacientes com câncer de mama localmente avançado: papel da tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose e exames de imagem convencional com tomografia computadorizada

Abstract Objective: To evaluate positron emission tomography/computed tomography (PET/CT) and conventional imaging tests for the detection of distant metastases in patients with locally advanced breast cancer. Materials and methods: We included 81 patients with breast cancer who had undergone 18F-fluorodeoxyglucose (FDG) PET/CT before treatment. Conventional imaging included the following: bone scintigraphy; chest X-ray (in 14.5%) or CT (in 85.5%); and abdominal ultrasound (in 10.8%), CT (in 87.8%), or magnetic resonance imaging (in 1.4%). Histopathology and clinical/imaging follow-up served as reference. Results: Distant metastases were observed in nine patients (11.1%). On patient-based analysis, conventional imaging identified distant metastases in all 9 patients. In one patient, the initial 18F-FDG PET/CT failed to demonstrate bone metastases that was evident on bone scintigraphy. In two patients, the CT scan failed to show extra-axillary lymph node metastases that were identified on 18F-FDG PET/CT. There was no significant difference between 18F-FDG PET/CT and conventional imaging in terms of their sensitivity for the detection of distant metastases in patients with locally advanced breast cancer. Conclusion: This study showed that 18F-FDG PET/CT and conventional imaging with CT scans had similar sensitivity for the diagnosis of distant metastases in patients with locally advanced breast cancer. 18F-FDG PET/CT can add information about extra-axillary lymph node involvements.

Resumo Objetivo: Avaliar a tomografia por emissão de pósitrons/tomografia computadorizada (PET/TC) e os exames de imagem convencionais na detecção de metástases em pacientes com câncer de mama localmente avançado. Materiais e métodos: Oitenta e uma pacientes com câncer de mama foram submetidas a PET/TC com 18F-fluordesoxiglicose (18F-FDG) antes do tratamento. Os exames de imagem convencionais incluíram cintilografia óssea, radiografia (14,5%) ou TC (85,5%) do tórax, e ultrassonografia (10,8%), TC (87,8%) ou ressonância magnética (1,4%) do abdome. A histopatologia e o seguimento clínico-imaginológico foram usados como padrão ouro. Resultados: Metástases a distância foram observadas em 9 pacientes (11,1%), sendo identificadas em todas as pacientes pelos exames de imagem convencionais. A PET/TC inicial não demonstrou metástase óssea em uma paciente, que foi identificada na cintilografia óssea. A TC não mostrou metástases em linfonodos extra-axilares, que foram demonstradas na PET/TC, em duas pacientes. Não houve diferença estatisticamente significante entre a PET/TC e os exames de imagem convencionais na detecção de metástases a distância nas pacientes com câncer de mama localmente avançado. Conclusão: Este estudo mostrou que a PET/TC e os exames de imagem convencionais têm sensibilidade similar no diagnóstico de metástases a distância nas pacientes com câncer de mama localmente avançado. A PET/TC pode adicionar informações sobre o envolvimento de linfonodos extra-axilares.

Qualidade de vida relacionada à voz e à deglutição, a curto prazo, em pacientes submetidos à radioiodoterapia por carcinoma diferenciado de tireoide / Short term quality of life related to voice and swallowing in patients undergoing ¹³¹i (iodine) for differentiated thyroid carcinoma

OBJETIVO: analisar a qualidade de vida relacionada à voz e à deglutição antes e após radioiodoterapia a curto prazo. MÉTODOS: indivíduos tireoidectomizados indicados à radioiodoterapia foram submetidos a dois questionários de qualidade de vida, relacionados à voz e à deglutição no pré e três meses após radioiodoterapia. RESULTADOS: foram estudados 32 pacientes, 84% do gênero feminino e 16%, do masculino, com média de idade de 46 anos. O tipo histológico mais encontrado foi o carcinoma papilífero clássico (56%). Os resultados indicaram tendência para melhor qualidade de vida associada à voz após três meses de radioiodoterapia. O protocolo de qualidade de vida relacionado à deglutição também indicou melhor qualidade de vida no segundo momento de avaliação. Observou-se maior predomínio com limitação mínima quanto ao questionário de qualidade de vida em deglutição. CONCLUSÃO: a qualidade de vida e dos sintomas vocais e de deglutição a curto prazo após radioiodoterapia é melhor em relação ao pré-tratamento. É necessário investigar outros aspectos como metabólicos, cirúrgicos e individuais para definir o real impacto da iodoterapia na qualidade de vida. .

PURPOSE: to analyze the quality of life related to voice and swallowing before and after radioiodine therapy in the short term. METHODS: thyroidectomized individuals indicated for RAI underwent two questionnaires on quality of life related to voice and swallowing before and three months after radioiodine therapy. RESULTS: thirty-two patients, 84% female and 16% male, were studied with a mean age of 46 years. Histological type was classic papillary carcinoma (56%). The results indicated a tendency for better quality of life with respect to voice three months after radioiodine therapy. The protocol for quality of life related to swallowing also indicated better quality of life in the second assessment. Greater minimal limitation on the quality of life questionnaire in swallowing was observed. CONCLUSION: quality of life and voice and swallowing symptoms in the short term after radioiodine therapy is better compared to pretreatment. It is necessary to investigate other aspects such as metabolic, surgical and individual to define the real impact of radioiodine therapy on quality of life. .

Correlation between PET/CT results and histological and immunohistochemical findings in breast carcinomas / Correlação entre resultado do PET/CT e achados histológicos e imuno-histoquímicos em carcinomas mamários

Objective To correlate the results of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) performed with a specific protocol for assessment of breasts with histological/immunohistochemical findings in breast carcinoma patients. Materials and Methods Cross-sectional study with prospective data collection, where patients with biopsy-confirmed breast carcinomas were studied. The patients underwent PET/CT examination in prone position, with a specific protocol for assessment of breasts. PET/CT findings were compared with histological and immunohistochemical data. Results The authors identified 59 malignant breast lesions in 50 patients. The maximum diameter of the lesions ranged from 6 to 80 mm (mean: 32.2 mm). Invasive ductal carcinoma was the most common histological type (n = 47; 79.7%). At PET/CT, 53 (89.8%) of the lesions demonstrated anomalous concentrations of 18F-FDG, with maximum SUV ranging from 0.8 to 23.1 (mean: 5.5). A statistically significant association was observed between higher values of maximum SUV and histological type, histological grade, molecular subtype, tumor diameter, mitotic index and Ki-67 expression. Conclusion PET/CT performed with specific protocol for assessment of breasts has demonstrated good sensitivity and was associated with relevant histological/immunohistochemical factors related to aggressiveness and prognosis of breast carcinomas. .

Objetivo Correlacionar o resultado da tomografia por emissão de pósitrons/tomografia computadorizada (PET/CT) com 18F-flúor-2-deoxi-D-glicose (18F-FDG) realizado com protocolo específico para avaliação das mamas com achados histológicos/imuno-histoquímicos em pacientes com carcinomas mamários. Materiais e Métodos Estudo transversal, com coleta prospectiva dos dados, em que foram estudadas pacientes com carcinomas mamários confirmados por biópsia. As pacientes incluídas foram submetidas a exame de PET/CT realizado em decúbito ventral, com protocolo específico para avaliação das mamas. Os achados do PET/CT foram comparados aos dados histológicos e imuno-histoquímicos. Resultados Foram identificadas 59 lesões mamárias malignas nas 50 pacientes incluídas no estudo. O diâmetro máximo das lesões variou de 6 a 80 mm (média : 32,2 mm). O tipo histológico mais comum foi o carcinoma ductal invasivo (n = 47; 79,7%). No PET/CT, 53 (89,8%) destas lesões apresentaram concentração anômala de 18F-FDG, com SUV máximo variando de 0,8 a 23,1 (média: 5,5). Houve associação estatisticamente significante entre maiores valores de SUV máximo e tipo histológico, grau histológico, subtipo molecular, diâmetro do tumor, índice mitótico e expressão de Ki-67. Conclusão O PET/CT realizado com protocolo específico para avaliação das mamas demonstrou boa sensibilidade e apresentou associação com importantes fatores histológicos/imuno-histoquímicos relacionados à agressividade e prognóstico dos carcinomas mamários. .

Metástase na mama originada de carcinoma ovariano: relato de caso e revisão da literatura / Breast metastasis from ovarian carcinoma: a case report and literature review

Carcinoma primário de ovário raramente origina metástase para mama, com poucos casos descritos na literatura. Os autores relatam um caso de uma paciente com carcinoma ovariano que evoluiu com metástase para mama após cerca de oito anos do diagnóstico inicial da neoplasia e realizam revisão bibliográfica do assunto, dando ênfase aos aspectos de imagem.

Primary ovarian carcinoma rarely metastasizes to the breast, and few cases are described in the literature. The authors report the case of a patient with ovarian carcinoma that developed breast metastasis eight years after the initial diagnosis, and present a literature review on this subject, emphasizing imaging findings.

Anatomical location of cervical uptake areas after total thyroidectomy with 131Iodine - SPECT-CT

Objective: The purpose of this study was to evaluate the use of SPECT-CT for the determination of the anatomical locations of the cervical 131Iodine uptake areas during 131Iodine-whole body (131I-WB) scans. Methods: One hundred fifty-four patients who had undergone total thyroidectomyfor differentiated thyroid carcinoma (DTC) and had 131I-WB scan with cervical uptake images were studied with SPECT-CT, from March 2003 to October 2006. Results: From the 154patients included, 124 were women (80.5%) and the mean age of 46.09 ± 14.77 years. 131I-WB was performed 1-2 months after surgery in 137 patients (89.0%). The percentage of cervical uptake found varied between 0.1 and 15.0% and its mean was 1.42 ± 2.05%. Using SPECT-CT, 223 foci of cervical 131Iodine uptake (CIU) were identified in 154 patients. CIU foci were localized to the thyroid bed in 17 patients, while 29 patients presented with CIU in the thyroid bed and the extra thyroid tissue and in both the thyroid bed and extra thyroid tissues in another 29 patients. Inthe remaining 108 subjects, the CIU were located outside of the thyroid bed, of which the most common locations were the sternothyroid muscle and the thyroid cartilage. Conclusions: The useof SPECT-CT demonstrated significant diversity in the anatomical locations of CIU foci observed during 131I-WB scans after thyroidectomy for DTC

Definition of gross tumor volume with FDG-18F PET-CT in patients with head and neck cancer: comparison of different delineation methods

Objective: Besides the high sensitivity and specificity of positron emission tomography (PET) for head and neck tumors, there is still a lack of consensus about how to use this method inradiotherapy planning. The aim of this study is to compare different gross tumor volume (GTV) obtained with PET images in comparison to the size of the target volume generated with CT scanalone, for treated and untreated head and neck lesions. Methods: Sixty lesions in fifty patients with head and neck squamous cell carcinoma were included in the study. Delineation of the GTV was achieved using computed tomography (CT) images alone (GTV-CT) and PET-CT images with the visual assessment method (GTVPET-CT) and standard uptake value (SUV) thresholds of 40, 50, 60 and 75 percent (GTV40%, GTV50%, GTV60%, GTV75%, respectively). Correlations were measured by the Spearman test and the Friedman test was used to verify differences between GTVs. Results: For all lesions (treated and untreated), only the GTVPET-CT showed a strong correlation with GTV-CT. For only the untreated lesions, GTVPET-CT and GTV75% showed a strong correlation with GTV-CT. The GTV50%, GTV60% and GTV75% showed statistically significant difference in relation to GTV-CT, while GTVPET-CT and GTV40% were similar to GTV-CT. Conclusion: The use of PET-CT changes the volume of the final target in head and neck tumors,depending on the methodology used to calculate the GTV. The results presented here showed that the GTV40% and the GTVPET-CT are those who are closer to the target volumes delineated by conventional CT

New applications of radioguided surgery in oncology

OBJECTIVE: To report oncological cases (excluding those related to breast cancer) for which radioguided surgery has been used in combination with the Radioguided Occult Lesion Localization technique. INTRODUCTION: Radioguided surgery enables a surgeon to identify lesions or tissues that have been preoperatively marked with radioactive substances. The Radioguided Occult Lesion Localization technique has been widely used to identify the sentinel lymph node and occult lesions in patients with breast cancer. However, few studies have reported the use of this technique for non-breast cancer pathologies. METHODOLOGY: In all cases, injection of Technecium-99m sulfur colloid was performed, directly inside or near by the suspicious lesion, guided by ultrasound or computed tomography, up to 36 hours prior to the surgical procedure. Intraoperative lesion detection was carried out using a gamma-probe. RESULTS: We report five oncology cases in which preoperative markings of the lesions were carried out using the Radioguided Occult Lesion Localization technique. The patients presented with the following: recurrence of renal cell carcinoma, cervical recurrence of papillary carcinoma of the thyroid, recurrence of retroperitoneal sarcoma, lesions of the popliteal fossa, and recurrence of rhabdomyosarcoma of a thigh. In each case, the lesions that were marked preoperatively were ultimately successfully excised. CONCLUSIONS: Radioguided surgery has proven to be a safe and effective alternative for the management of oncology patients. The Radioguided Occult Lesion Localization technique can be useful in selected cases where suspect lesions may be difficult to identify intraoperatively, due to their dimensions or anatomical location. The procedure allows for more conservative excisions and reduces the surgery-related morbidity.

Fusão de imagens PET-TC na avaliação do carcinoma espinocelular de cabeça e pescoço / PET-CT imaging fusion in the assessment of head and neck carcinoma

OBJETIVO: Os autores estabeleceram uma metodologia para avaliar carcinoma espinocelular de cabeça e pescoço, identificando e distinguindo áreas de grande atividade metabólica dentro da neoplasia, associando dados simultaneamente adquiridos, obtidos por diferentes modalidades de aquisição de imagens, combinando informações metabólicas e anatômicas num único exame. MATERIAIS E MÉTODOS: A população estudada consistiu de 17 pacientes com carcinoma espinocelular pertencentes aos arquivos do Departamento de Imagem do Hospital do Câncer, São Paulo. As imagens de tomografia computadorizada (TC) e da tomografia por emissão de pósitrons (PET) com 2-[F-18]-fluoro-2-deoxi-d-glucose (18F-FDG-PET) foram simultaneamente adquiridas utilizando aparelho não dedicado. Os dados originais foram transferidos para uma estação de trabalho independente com o programa Entegra 2NT para gerar a fusão de imagens da PET e TC. RESULTADOS: Os achados foram definidos como positivos na presença de focos com aumento da concentração do radiofármaco em áreas não relacionadas à sua distribuição normal. CONCLUSÃO: A fusão de imagens simultaneamente adquiridas num único exame (18F-FDG-PET e TC) possibilitou o mapeamento topográfico metabólico das lesões estudadas e foi possível localizar áreas de maior atividade metabólica dentro do próprio tumor, verificando recidivas ou metástases, possibilitando aumentar as opções quanto ao planejamento radioterápico ou cirúrgico.

OBJECTIVE: The authors have established a methodological approach to evaluate head and neck squamous cell carcinoma aiming at identifying and distinguishing high metabolic activity inside the lesion, combining in a single examination, functional, metabolic and morphological data simultaneously acquired by means of different non-dedicated positron emission tomography (PET)-computed tomography (CT) device. MATERIALS AND METHODS: The study population included 17 patients with head and neck squamous cell carcinoma submitted to a non-dedicated 18F-FDG-PET imaging at Department of Diagnostic Imaging of Hospital do Câncer, São Paulo, SP, Brazil. CT and 18F-FDG-PET images were simultaneously acquired in a non-dedicated device. The original data were transferred to an independent workstation by means of the Entegra 2 NT software to generate PET-CT imaging fusion. RESULTS: The findings were defined as positive in the presence of a well defined focal area of increased radiopharmaceutical uptake in regions not related with the normal biodistribution of the tracer. CONCLUSION: The fusion of simultaneously acquired images in a single examination (18F-FDG-PET and CT) has allowed the topographic-metabolic mapping of the lesion as well as the localization of high metabolic activity areas inside the tumor, indicating recidivation or metastasis and widening the array of alternatives for radiotherapy or surgical planning.

Initial Results and Clinical Application of Non Dedicated 18-FDG/PET in Head and Neck Oncology

Imaging procedures are important methods for properstage and treatment planning. Especially in previouslytreated patients, although not perfectly accurate. PETscan is a functional and imaging technique that has beenused to diagnose and stage recurrent cancer fromdifferent sites. The combination of computedtomography coupled with FDG-PET (18-FDG-PET/CT)reaches high quality anatomical and functional images.OBJECTIVE: To describe the initial results of FDG-PET/CT performed at a single institution. MATERIAL ANDMETHODS: This technique was used in 63 patients withhead and neck tumors. The purpose of the exam was: a)to rule out recurrent disease - 55 patients; b) to search forhidden primary tumor - 2 patients; and c) postoperativefollow-up of residual disease - 6 patients. Computedtomography (CT) was performed in 56 cases (88.9%).Pathological confirmation was obtained in 24 cases(38.1%), all the remaining cases were considered negativebased on clinical follow-up information with no evidenceof recurrent disease 12 months after the PET/CT exam.RESULTS: Overall results for the accuracy of FDG-PETwere: 93.9% of sensitivity, 64.2% of specificity, 75.6% ofpositive predictive value and 90.0% of negativepredictive value. FDG-PET was able to find 1 out of 2undetected primary tumors (base of the tongue). Thebest results were obtained regarding the detection oflocal and distant recurrences of larynx, thyroid and oralcavity cancers. CONCLUSION: The FDG-PET/CT fusionimage makes anatomical localization easier and theaccuracy for detection of recurrent disease was found tobe higher than CT alone.

Aplicação das imagens de fusão PET/CT não dedicado com 18f-f-dg como método de avaliação das lesões pulmonares em pacientes oncológicos / Evaluation of non-dedicated 18F-FDG-PET/CT image fusion as an assessment method of pulmonary lesions in cancer patients

Nódulos e massas são lesões pulmonares radiológicas detectadas nos pacientes oncológicos, porém quando as suas características são indeterminadas faz-se necessária a elucidação de sua etiologia para o tratamento ou avaliação de resposta terapêutica. O PET dedicado com 18F-FDG (Fluordeoxiglicose) é um método de imagem que reflete o maior metabolismo de glicose presente nos tumores malignos, porém apresenta limitações de localização anatômica e depende do uso de equipamentos dedicados de alto custo. A utilização de imagens de CT integrada a equipamentos não dedicados de baixo custo foi recentemente introduzida como opção, sendo conhecido como PET-CT não dedicado. Objetivo: Determinar a eficiência do PET-CT não dedicado na avaliação de lesões pulmonares e seu impacto na conduta clínica. Metodologia: Foram prospectivamente estudados 64 pacientes oncológicos com lesões pulmonares indeterminadas utilizando-se PET-CT não dedicado com 18F-FDG. Os resultados dos estudos foram comparados com biópsias, evolução clínica e radiológica, sendo ainda avaliadas as alterações de conduta decorrentes das informações obtidas com o exame. Resultados: Observou-se sensibilidade de 95,1%, especificidade de 86,3%, acurácia de 92,1%, valor preditivo positivo de 93,0% e valor preditivo negativo de 90,4%; que se mostraram equivalentes aos observados com o PET dedicado na literatura. As alterações de conduta estiveram presentes em 32% dos casos. Conclusão: O PET-CT não dedicado com 18F-FDG é um método eficiente na avaliação das lesões pulmonares em pacientes oncológicos, demonstrando equivalência ao PET dedicado e resultando em alterações de conduta clínica em um terço dos casos...(AU)

Lung nodules and masses are radiological lesions frequently detected in cancer patients. The characterization of their nature is necessary to treatment and evaluation of therapeutic response but it is sometimes difficult due to the lack of morphological characteristics associated to it. Metabolic imaging with 18F-FDG (fluorodeoxyglucose ), a glucose analogue that reflects higher metabolic malignant tumor rates, using a dedicated PET device may is useful, but it suffers from limitation of topographic precise location and from the necessity of a dedicated high-cost device. Recently a new approach with the use of anatomical CT images linked to a non-dedicated lower-cost device was introduced as an option. Objective: Evaluate the use of a nondedicated PET -CT in the assessment of pulmonary lesions and their impact on clinicai management. Method: Sixty-four cancer patients with indeterminate lung lesions were prospectively evaluated using non-dedicated PET-CT with 18F-FDG. Results were compared with biopsy, clinicai and radiological evolution and management changes resulting from the test were recorded. Results: A sensitivity of 95,1 °/o, a specificity of 86,3°/o and an accuracy of 92,1 °/o were observed; also a predictive positive value of 93,0°/o and a predictive negative value of 90,4°/o were found and an impact on clinicai management observed in 32°/o of the cases. Conclusion: Nondedicated PET -CT with 18F-FDG is an efficient method in the evaluation of pulmonary lesions in cancer patients, presenting results equivalent to a dedicated PET with clinicai management influenced in one third of the cases (AU)

Medicina nuclear na odontologia / Nuclear medicine in dentistry

Para o diagnóstico e tratamento de doenças da boca, muitas vezes é necessária uma avaliaçäo sistêmica do paciente, visto que outros órgäos podem estar envolvidos pela doença. Exames complementares säo cada vez mais necessários na avaliaçäo semiológica, e a Medicina Nuclear, devido à sua alta sensibilidade, tem conquistado ampla aplicaçäo na Medicina e na Odontologia. Neste artigo, os autores apresentam uma revisäo da literatura sobre o uso da Medicina Nuclear em Odontologia, ilustrando o assunto com casos atendidos no Hospital do Câncer A. C. Camargo, em Säo Paulo