Correlation of 18F-sodium fluoride uptake and radiodensity in extraosseous metastases of medullary thyroid carcinoma

ABSTRACT Objective: Although 18F-sodium fluoride (18F-NaF) uptake is frequently observed in extraosseous metastases of medullary thyroid carcinoma (MTC) with calcification, it can also occur in metastatic sites without visible calcium deposition, leading to the hypothesis that visually undetectable calcium accumulation may be responsible for this uptake. The aim of this study was to indirectly support this hypothesis by analyzing the correlation between the degree of 18F-NaF uptake and radiodensity in extraosseous MTC metastases, since calcium deposition can increase attenuation even when not visually detectable. Subjects and methods: Extraosseous metastatic lesions of 15 patients with MTC were evaluated using 18F-NaF positron-emission tomography (PET)/computed tomography (CT) and segmented by levels of standardized uptake value (SUV). The correlation between mean SUV and mean Hounsfield unit (HU) values was assessed for the entire group of segments and for two subgroups with different mean HU values. Results: Very high correlations were observed between mean SUV and mean HU values for both the entire group of segments and the subgroup with a mean HU value greater than 130 (p = 0.92 and p = 0.95, respectively; p < 0.01). High correlation (p = 0.71) was also observed in the subgroup with mean HU values ranging from 20 to 130 (p < 0.01). Conclusion: The findings of the present study suggest that there is an association between 18F-NaF uptake and calcium deposition in extraosseous metastases of MTC, supporting the hypothesis that visually undetectable calcium accumulation may be responsible for 18F-NaF uptake in regions without visible calcium deposition.

Prognostic Value of Bone Marrow Uptake Using 18F-FDG PET/CT Scans in Solid Neoplasms.

BACKGROUND: Fluorine-18-fluorodeoxyglucose positron emission tomography/computerized tomography (18F-FDG PET/CT) uptake is known to increase in infective and inflammatory conditions. Systemic inflammation plays a role in oncologic prognosis. Consequently, bone marrow increased uptake in oncology patients could potentially depict the systemic cancer burden. METHODS: A single institute cohort analysis and a systematic review were performed, evaluating the prognostic role of 18F-FDG uptake in the bone marrow in solid neoplasms before treatment. The cohort included 113 esophageal cancer patients (adenocarcinoma or squamous cell carcinoma). The systematic review was based on 18 studies evaluating solid neoplasms, including gynecological, lung, pleura, breast, pancreas, head and neck, esophagus, stomach, colorectal, and anus. RESULTS: Bone marrow 18F-FDG uptake in esophageal cancer was not correlated with staging, pathological response, and survival. High bone marrow uptake was related to advanced staging in colorectal, head and neck, and breast cancer, but not in lung cancer. Bone marrow 18F-FDG uptake was significantly associated with survival rates for lung, head and neck, breast, gastric, colorectal, pancreatic, and gynecological neoplasms but was not significantly associated with survival in pediatric neuroblastoma and esophageal cancer. CONCLUSION: 18F-FDG bone marrow uptake in PET/CT has prognostic value in several solid neoplasms, including lung, gastric, colorectal, head and neck, breast, pancreas, and gynecological cancers. However, future studies are still needed to define the role of bone marrow role in cancer prognostication.

18F-FDG-PET/CT-measured parameters as potential predictors of residual disease after neoadjuvant chemoradiotherapy in patients with esophageal carcinoma.

Objective: To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer. Materials and Methods: The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by 18F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of 18F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen. Results: Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD. Conclusion: The use of 18F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.

Objetivo: Avaliar os valores máximo e médio de captação padronizada, o valor metabólico do tumor e a glicólise total da lesão do local do tumor primário, medidos no estudo de 18F-FDG-PET/CT realizado antes e depois da quimiorradioterapia neoadjuvante (nQRT) em pacientes com câncer de esôfago, como preditores de doença residual (DR). Materiais e Métodos: Os valores máximo e médio de captação padronizada e os parâmetros volumétricos (valor metabólico do tumor e glicólise total da lesão) da 18F-FDG-PET/CT realizada em 39 pacientes antes e após a nQRT para carcinoma de esôfago foram avaliados para RD. Usamos curvas receiver operating characteristic (ROC) para analisar o desempenho diagnóstico dos parâmetros 18F-FDG-PET/CT na definição de RD. O estudo anatomopatológico foi utilizado como padrão ouro. Resultados: Dezoito pacientes (46%) apresentaram DR após a nQRT. Áreas estatisticamente significativas sob a curva ROC para predizer DR foram obtidas para as quatro variáveis nos estudos realizados após a nQRT, com áreas sob a curva ROC semelhantes em torno de 0,72. Considerando a presença de captação visualmente detectável (captação maior que o background) no local da lesão primária após a nQRT como resultado positivo, teríamos uma sensibilidade de 94% e uma especificidade de 48% para detecção de DR. Conclusão: A 18F-FDG-PET/CT pode ser útil para detectar a presença de doença neoplásica residual no câncer de esôfago após a nQRT.

18F-FDG-PET/CT-measured parameters as potential predictors of residual disease after neoadjuvant chemoradiotherapy in patients with esophageal carcinoma / 18F-FDG-PET/CT após quimiorradioterapia neoadjuvante em pacientes com carcinoma de esôfago como potencial preditor de doença residual

Abstract Objective: To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer. Materials and Methods: The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by 18F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of 18F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen. Results: Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD. Conclusion: The use of 18F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.

Resumo Objetivo: Avaliar os valores máximo e médio de captação padronizada, o valor metabólico do tumor e a glicólise total da lesão do local do tumor primário, medidos no estudo de 18F-FDG-PET/CT realizado antes e depois da quimiorradioterapia neoadjuvante (nQRT) em pacientes com câncer de esôfago, como preditores de doença residual (DR). Materiais e Métodos: Os valores máximo e médio de captação padronizada e os parâmetros volumétricos (valor metabólico do tumor e glicólise total da lesão) da 18F-FDG-PET/CT realizada em 39 pacientes antes e após a nQRT para carcinoma de esôfago foram avaliados para RD. Usamos curvas receiver operating characteristic (ROC) para analisar o desempenho diagnóstico dos parâmetros 18F-FDG-PET/CT na definição de RD. O estudo anatomopatológico foi utilizado como padrão ouro. Resultados: Dezoito pacientes (46%) apresentaram DR após a nQRT. Áreas estatisticamente significativas sob a curva ROC para predizer DR foram obtidas para as quatro variáveis nos estudos realizados após a nQRT, com áreas sob a curva ROC semelhantes em torno de 0,72. Considerando a presença de captação visualmente detectável (captação maior que o background) no local da lesão primária após a nQRT como resultado positivo, teríamos uma sensibilidade de 94% e uma especificidade de 48% para detecção de DR. Conclusão: A 18F-FDG-PET/CT pode ser útil para detectar a presença de doença neoplásica residual no câncer de esôfago após a nQRT.

Whole Skeletal Mean SUV Measured on 18F-NaF PET/CT Studies as a Prognostic Indicator in Patients with Bone Metastatic Breast Cancer.

In this work we assessed the association between the whole skeletal mean standardized uptake value (SUV) measured on 18F-NaF PET/CT studies and the overall survival (OS) of bone metastatic breast cancer patients. Methods: We retrospectively analyzed 176 patients with breast cancer and bone metastatic disease who performed 18F-NaF PET/CT studies. The outcomes of the patients (dead or alive) were established based on the last information available on their files. The mean and maximum SUVs were measured in a whole skeletal volume of interest (wsVOI). The wsVOI was defined based on the CT component of the PET/CT study using Hounsfield Units thresholds. The wsVOI was then applied on the 18F-NaF PET image. Univariate analyses were performed to assess the association of the SUVs with OS. We also analyzed the association of the age of the patients, the presence of visceral metastatic disease, histological subtypes, presence of hormone receptors, human epidermal growth factor receptor 2 expression and the creatinine, CA15-3 and alkaline phosphatase (ALP) levels with OS. The variables statistically significant in the univariate analyses were included in a multivariate cox regression survival analysis. Results: In the univariate analyses there were associations of the mean and maximum whole skeletal SUVs, estrogen receptor status and the CA15-3 and ALP levels with OS. In the multivariate analysis, all the variables that were statistically significant in the univariate analysis but the CA15-3 were associated with OS. Conclusion: In patients with bone metastatic breast cancer, the whole skeletal mean SUV is an independent predictor of overall survival.

Comparison of 18F-NaF PET/CT with Other Imaging Methods in the Detection of Bone Metastases in Patients with Medullary Thyroid Cancer: a Report of a Series of 31 Cases.

PURPOSE: To compare the 18F-NaF PET/CT studies (18F-NaF) with other imaging methods in the detection of skeletal metastases (SM) in patients with medullary thyroid cancer (MTC). METHODS: We retrospectively analyzed 31 patients with MTC who performed 18F-NaF to assess SM. The results of the 18F-NaF were compared with other imaging methods performed for metastasis detection: 99Tc-MDP bone scan (BS), magnetic resonance imaging (MRI), contrast-enhanced CT (CT), and 68Ga-Dotatate and 18F-FDG PET/CT studies. A qualitative analysis comparing the 18F-NaF findings with the ones of the other methods was performed, and the results were classified as superior (>), equal (=), and inferior (<). RESULTS: Eleven patients had no bone metastases detected on any of the imaging methods used. Twenty patients presented SM depicted on 18F-NaF. Of these 20 patients, 12 performed bone scan (in 9 18F-NaF > BS and in 3 18F-NaF = BS), 1 performed 18F-FDG (18F-NaF > 18F-FDG), 4 performed 68Ga-Dotatate (in 2 18F-NaF > 68Ga-Dotatate and in 2 18F-NaF = 68Ga-Dotatate), 20 performed CT of at least one body segment (in 15 18F-NaF = CT and in 5 18F-NaF > CT), and 16 performed MRI of at least one body segment, and in all of them, the 18F-NaF was equal to the MRI. Beside this, the 18F-NaF detected SM in body segments not routinely scanned in MRI and CT. CONCLUSION: In patients with MTC, the 18F-NaF seems to be equal or superior to other imaging modalities in the detection of SM and allows the analysis of the whole skeletal in a single study.

Brain Metastasis of Medullary Thyroid Carcinoma Without Macroscopic Calcification Detected First on 68Ga-Dotatate and Then on 18F-Fluoride PET/CT.

We report a case of a medullary thyroid carcinoma noncalcified brain metastasis characterized on Ga-dotatate PET/CT but not on an F-fluoride PET/CT performed 1 month later. Subsequent F-fluoride PET/CT studies performed 7 and 19 months after the Ga-dotatate PET/CT study demonstrated focal uptake in the metastasis. The CT images of the last PET/CT study also depicted a small focus of calcification beginning in the metastatic site.

Bone marrow uptake of 18F-fluorodeoxyglucose in Hodgkin lymphoma without bone involvement: comparison between patients with and without B symptoms.

OBJECTIVE: To compare the degree of benign bone marrow uptake of 18F-fluorodeoxyglucose (18F-FDG) between Hodgkin lymphoma patients with and without B symptoms. MATERIALS AND METHODS: We analyzed the medical charts of 74 Hodgkin lymphoma patients who underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) prior to the initiation of therapy between October 2010 and September 2013. In all of the patients, the bone marrow biopsy was negative and the 18F-FDG PET/CT images did not suggest bone marrow involvement. Of the 74 patients evaluated, 54 presented inflammatory (B) symptoms and 20 did not. Regions of interest (ROIs) were drawn on the sternum, the proximal thirds of the humeri, the proximal thirds of the femora, and both iliac wings (totaling seven ROIs per patient). To compare the patients with and without B symptoms, in terms of standardized uptake values (SUVs) for the seven ROIs, we used the Mann-Whitney U test. RESULTS: For six of the ROIs, the SUVs were higher in the patients with B symptoms than in those without, and the difference was statistically significant (p < 0.05). There was also a tendency toward a statistically significant difference between the two groups in terms of the SUV for the right iliac wing ROI (p = 0.06). CONCLUSION: In our sample, the presence of B symptoms was associated with increased 18F-FDG uptake in bone marrow.

OBJETIVO: Comparar o grau de absorção benigna de 18F-fluordesoxiglicose (18F-FDG) na medula óssea de pacientes com linfoma de Hodgkin com e sem sintomas B. MATERIAIS E MÉTODOS: Analisamos os prontuários de 74 pacientes com linfoma de Hodgkin submetidos a tomografia por emissão de pósitrons/tomografia computadorizada (PET/CT) com 18F-FDG antes do início da terapia entre outubro de 2010 e setembro de 2013. Em todos os pacientes, a biópsia da medula óssea foi negativa e as imagens de 18F-FDG PET/CT não sugeriram envolvimento da medula óssea. Dos 74 pacientes avaliados, 54 apresentaram sintomas inflamatórios (B) e 20 não. As regiões de interesse (ROIs) foram desenhadas no esterno, nos terços proximais dos úmeros, nos terços proximais dos fêmures e nas duas asas ilíacas (totalizando sete ROIs por paciente). Para comparar os pacientes com e sem sintomas B, em termos dos standardized uptake values (SUVs) para as sete ROIs, utilizamos o teste U de Mann-Whitney. RESULTADOS: Para seis das ROIs, os SUVs foram maiores nos pacientes com sintomas B do que nos pacientes sem, e a diferença foi estatisticamente significante (p < 0,05). Houve também tendência para uma diferença estatisticamente significante entre os dois grupos em termos do SUV para a ROI da asa ilíaca direita (p = 0,06). CONCLUSÃO: Na nossa amostra, a presença de sintomas B foi associada ao aumento da captação de 18F-FDG na medula óssea.

Bone marrow uptake of 18F-fluorodeoxyglucose in Hodgkin lymphoma without bone involvement: comparison between patients with and without B symptoms / Captação de 18F fluordesoxiglicose na medula óssea em pacientes com linfoma de Hodgkin sem comprometimento ósseo: comparação entre pacientes com e sem sintomas B

Abstract Objective: To compare the degree of benign bone marrow uptake of 18F-fluorodeoxyglucose (18F-FDG) between Hodgkin lymphoma patients with and without B symptoms. Materials and Methods: We analyzed the medical charts of 74 Hodgkin lymphoma patients who underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) prior to the initiation of therapy between October 2010 and September 2013. In all of the patients, the bone marrow biopsy was negative and the 18F-FDG PET/CT images did not suggest bone marrow involvement. Of the 74 patients evaluated, 54 presented inflammatory (B) symptoms and 20 did not. Regions of interest (ROIs) were drawn on the sternum, the proximal thirds of the humeri, the proximal thirds of the femora, and both iliac wings (totaling seven ROIs per patient). To compare the patients with and without B symptoms, in terms of standardized uptake values (SUVs) for the seven ROIs, we used the Mann-Whitney U test. Results: For six of the ROIs, the SUVs were higher in the patients with B symptoms than in those without, and the difference was statistically significant (p < 0.05). There was also a tendency toward a statistically significant difference between the two groups in terms of the SUV for the right iliac wing ROI (p = 0.06). Conclusion: In our sample, the presence of B symptoms was associated with increased 18F-FDG uptake in bone marrow.

Resumo Objetivo: Comparar o grau de absorção benigna de 18F-fluordesoxiglicose (18F-FDG) na medula óssea de pacientes com linfoma de Hodgkin com e sem sintomas B. Materiais e Métodos: Analisamos os prontuários de 74 pacientes com linfoma de Hodgkin submetidos a tomografia por emissão de pósitrons/tomografia computadorizada (PET/CT) com 18F-FDG antes do início da terapia entre outubro de 2010 e setembro de 2013. Em todos os pacientes, a biópsia da medula óssea foi negativa e as imagens de 18F-FDG PET/CT não sugeriram envolvimento da medula óssea. Dos 74 pacientes avaliados, 54 apresentaram sintomas inflamatórios (B) e 20 não. As regiões de interesse (ROIs) foram desenhadas no esterno, nos terços proximais dos úmeros, nos terços proximais dos fêmures e nas duas asas ilíacas (totalizando sete ROIs por paciente). Para comparar os pacientes com e sem sintomas B, em termos dos standardized uptake values (SUVs) para as sete ROIs, utilizamos o teste U de Mann-Whitney. Resultados: Para seis das ROIs, os SUVs foram maiores nos pacientes com sintomas B do que nos pacientes sem, e a diferença foi estatisticamente significante (p < 0,05). Houve também tendência para uma diferença estatisticamente significante entre os dois grupos em termos do SUV para a ROI da asa ilíaca direita (p = 0,06). Conclusão: Na nossa amostra, a presença de sintomas B foi associada ao aumento da captação de 18F-FDG na medula óssea.

Iodine/FDG "Flip-Flop" Phenomenon Inside a Large Metastatic Thyroid Cancer Lesion Better Characterized on SPECT/CT and PET/CT Studies.

Iodine/FDG "flip-flop" phenomenon inside large metastatic thyroid cancer lesions has been rarely described. We present a case of this phenomenon better characterized using SPECT/CT and PET/CT studies.