Comparison of Oral and IV 18 F-NaF PET/CT Administration in the Assessment of Bone Metastases in Patients With Breast or Prostate Cancers.

PURPOSE: The aim of this study was to compare oral and IV administrations of 18 F-NaF PET/CT for detection of suspicious bone metastatic lesions of breast and prostate cancers. PATIENTS AND METHODS: Thirty-six patients with breast (n = 23) or prostate (n = 13) cancers and high risk for bone metastases were prospectively evaluated. All patients underwent 2 PET/CT studies after IV and oral 18 F-NaF administration within a 2 to 23 days interval between them. The maximum SUVs from the same suspicious lesions (≤5 index lesions per patient) in both studies were measured. The target-to-background ratio (TBR), defined as the relation between the lesion maximum SUV and the whole skeletal mean SUV, was calculated for each lesion. The TBRs in the same lesion calculated using the 2 administration routes were compared. The agreements between 2 physicians in the definition of the number of lesions in both studies were also assessed using weighted κ. RESULTS: One hundred thirty-four pairs of lesions were analyzed. There was no significant statistical difference between the median TBRs ( P = 0.212) for IV (10.33) and oral (10.85). Excellent intraobserver agreement was observed between IV and oral routes: weighted κ of 1.0 (95% confidence interval, 0.92-1.0) and 0.92 (95% confidence interval, 0.81-0.99) for physicians 1 and 2, respectively. The interobserver coefficients were 0.82 and 0.87 for "oral versus oral" and "IV versus IV," respectively. CONCLUSIONS: 18 F-NaF PET/CT studies using oral and IV routes present comparable performance; thus, it is possible to use oral route in patients with difficult venous access.

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.

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 / 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.

Prognostic value of 18F-fluorodeoxyglucose PET/computed tomography metabolic parameters measured in the primary tumor and suspicious lymph nodes before neoadjuvant therapy in patients with esophageal carcinoma.

BACKGROUND: 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) metabolic parameters are prognostic indicators in several neoplasms. This study aimed to evaluate the prognostic value of the maximum and average standardized uptake value (SUVmax and SUVavg), metabolic tumor value (MTV), and total lesion glycolysis (TLG) measured in the primary tumor and suspicious lymph nodes preneoadjuvant therapy in patients submitted to surgical resection for esophageal cancer. METHODS: A cohort of 113 patients with esophageal cancer who performed 18F-FDG PET/CT preneoadjuvant therapy was assessed. The association of the SUV, MTV, and TLG measured in the primary tumor and in the suspicious lymph nodes with the overall survival was assessed. It was also analyzed other potentially confounding variables such as age, sex, clinical stage, and histologic subtype. The analyses were performed using Kaplan-Meier curve, log-rank test, and Cox regression. RESULTS: The univariate analyses showed that the MTV and TLG in the primary tumor, the SUV in the suspicious lymph nodes, the age, the histologic subtype, and the clinical stage were associated with survival after surgery (P ≤ 0.05). In the Cox regression multivariate analyses, all variables identified in the univariate analyses but the clinical stage were associated with survival after surgery (P ≤ 0.05). CONCLUSION: In esophageal cancer patients, some of the 18F-FDG PET/CT metabolic parameters measured in the primary tumor and in the suspicious lymph nodes before the neoadjuvant therapy are independent indicators of overall survival and appear to be more important than the clinical stage in the prognostic definition of this group of patients.

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.

Intramastoid Phosphaturic Mesenchymal Tumor Causing Hypophosphatemic Osteomalacia Detected on 68Ga-DOTATATE PET/CT But Not on 99mTc-Sestamibi and 18F-FDG Scans.

68Ga-DOTATATE uptake in mesenchymal tumors causing hypophosphatemic osteomalacia has been recently described. Herein, we present a case of 68Ga-DOTATATE uptake in an intramastoid phosphaturic mesenchymal tumor that had not been depicted in previous 99mTc-Sestamibi and 18F-FDG scans. The lesion was surgically removed and the phosphorus level increased to the normal range.

Comparison of the Variability of SUV Normalized by Skeletal Volume with the Variability of SUV Normalized by Body Weight in 18F-Fluoride PET/CT.

Our objective was to test the hypothesis that variability in SUV normalized by skeletal volume (SV) in 18F-fluoride (18F-NaF) PET/CT studies is lower than variability in SUV normalized by body weight (BW). Methods: The mean SUV (SUVmean) was obtained for whole skeletal volume of interest (wsVOI) in 163 selected 18F-NaF PET/CT studies. These studies were performed to investigate bone metastases and were considered to have normal results. SUVmean was calculated with normalization by BW (BW SUVmean), with normalization by SV (SV SUVmean), and without normalization (WN SUVmean). The total SV for each patient was also estimated on the basis of the wsVOI defined on the CT component of the PET/CT study. SUVmean variability for each patient was estimated as the absolute value of the difference between the SUVmean for the patient and the mean of the SUVmean for the whole group of patients, divided by the mean of the SUVmean for the whole group of patients. The variabilities of SUVmean calculated by the 3 methods were compared using a paired 1-tailed Wilcoxon test. Results: The mean variability for the BW, SV, and WN SUVmean was 0.16, 0.13, and 0.16, respectively. There were statistically significant differences between SV and BW SUVmean variability (P = 0.03) and between SV and WN SUVmean variability (P < 0.01). There was no statistically significant difference between BW and WN SUVmean variability (P = 0.4). Conclusion: In patients with normal 18F-NaF PET/CT results, SV SUVmean presents lower variability than BW SUVmean.

18F-Fluoride Uptake in Soft Tissue Metastases of Medullary Thyroid Carcinoma as a Marker of Progressive Calcification.

F-fluoride (F-NaF) uptake in soft tissue metastases of medullary thyroid carcinoma (MTC) has been reported. However, the evolution of these metastatic sites has rarely been assessed. We present a case of F-NaF uptake in multiple liver metastases of MTC initially without macroscopic calcification. The CT follow-up studies showed a progressive calcium deposition in the lesions. Therefore, this case suggests that the F-NaF uptake in MTC metastases could potentially be a marker of an ongoing calcification process instead of an inert deposit of calcium.

Bone and Calcified Soft Tissue Metastases of Medullary Thyroid Carcinoma Better Characterized on 18F-Fluoride PET/CT than on 68Ga-Dotatate PET/CT.

Herein, we report a case of a 19-year-old man with multiple endocrine neoplasia type 2B (MEN2B) and medullary thyroid carcinoma (MTC) diagnosed when he was 12 years of age. The patient had previously undergone total thyroidectomy, cervical radiotherapy, and chemotherapy. He progressed with known bone, pulmonary, and lymph node metastases and was scanned with 18F-fluoride (18F-NaF) and 68Ga-dotatate whole-body positron emission tomography/computed tomography (PET/CT) for metastatic disease monitoring. We found that the MTC bone metastases and soft tissue calcified metastases were better characterized on 18F-NaF PET/CT than on 68Ga-dotatate PET/CT. This case illustrates that the 18F-NaF PET/CT could be helpful not only to the detection of bone metastases but also to the detection of calcified soft tissue metastases in patients with MTC.