RESUMO
PURPOSE: The study sought to determine the incidence of incidental findings on whole-body positron emission tomography with computed tomography (PET/CT) imaging and the average costs of investigations to follow-up or further characterize incidental findings. METHODS: Imaging reports of 215 patients who underwent whole-body PET/CT imaging were retrospectively reviewed. Our provincial picture archiving and communication system was queried and patient charts were reviewed to identify all investigations performed to follow-up incidental findings within 1 year of the initial PET/CT study. Costs of follow-up imaging studies (professional and technical components) and other diagnostic tests and procedures were determined in Canadian dollars (CAD) and U.S. dollars (USD) using the 2015 Ontario Health Insurance Plan Schedule of Benefits and Fees and 2016 U.S. Medicare Physician Fee Schedule, respectively. RESULTS: At least 1 incidental finding was reported in 161 reports (74.9%). The mean number of incidental findings ranged from 0.64 in patients <45 years of age to 2.2 in patients 75 years of age and older. Seventy-five recommendations for additional investigations were made for 64 (30%) patients undergoing PET/CT imaging, and 14 of those were carried out specifically to follow-up incidental findings. Averaged across all 215 patients, the total cost of investigations recommended to follow-up incidental findings was CAD$105.51 (USD$127.56) per PET/CT study if all recommendations were acted on, and CAD$22.77 (USD$29.14) based on investigations actually performed. CONCLUSIONS: As the incidence of incidental findings increases with age and a larger proportion of elderly patients is expected as population demographics change, it will be increasingly important to consider incidental findings on PET/CT imaging with standardized approaches to follow-up.
Assuntos
Fluordesoxiglucose F18 , Achados Incidentais , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Imagem Corporal Total/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Ontário , Estudos Retrospectivos , Adulto JovemRESUMO
OBJECTIVE: To explore the relationship between metabolic activity and outcome in patients with extremity sarcomas. METHODS: Between June 2004 and December 2011, 120 patients with newly diagnosed limb and girdle sarcomas underwent FDG-PET/CT for disease staging prior to curative intent treatment. The maximum standardized uptake value (SUV(max)) was measured for each primary tumor and correlated with outcome. Progression-free survival and overall survival (OS) were analyzed using the Kaplan-Meier method. RESULTS: Soft-tissue sarcomas were more frequent (68%) than bone (27%) or cartilage (5%) tumors. Median follow-up was 33.2 months. 51% of patients progressed during the follow-up interval and 38% died. SUV(max) was dichotomized with a cut-point of 10.3. Patients with SUV(max) < 10.3 had better DFS and OS compared with patients with SUV(max) ≥ 10.3 (P < 0.001 and P < 0.001, respectively [log-rank test]). Multivariate analysis confirmed that even after adjusting for age, sex, site, tumor type (bone vs. soft-tissue), grade, and stage; an SUV(max) ≥ 10.3 correlated with a twofold risk of progression and 2.4 times greater risk of death (hazard ratio [HR] 2.0, 95% CI, 1.1-3.7, and HR, 2.4, 95% CI, 1.1-4.9). CONCLUSION: SUV(max) is an independent adverse prognostic factor for both progression and OS in patients with extremity sarcomas.
Assuntos
Extremidades , Fluordesoxiglucose F18/metabolismo , Tomografia por Emissão de Pósitrons , Sarcoma/metabolismo , Sarcoma/terapia , Tomografia Computadorizada por Raios X , Adulto , Idoso , Quimioterapia Adjuvante , Intervalo Livre de Doença , Extremidades/patologia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons/métodos , Valor Preditivo dos Testes , Prognóstico , Compostos Radiofarmacêuticos/metabolismo , Radioterapia Adjuvante , Sarcoma/diagnóstico , Sarcoma/patologia , Resultado do TratamentoRESUMO
PURPOSE: Imaging is important to identify subclinical changes and for treatment planning in patients with osteonecrosis of the jaw (ONJ) exposed to antiresorptive therapy. The aim of this study was to compare the findings at radiography with those at fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography (CT) for patients with ONJ related to antiresorptive therapy. MATERIALS AND METHODS: A cross-sectional retrospective analysis of patients with clinically identified ONJ lesions of the mandible was performed. Two imaging modalities were evaluated for each patient: plain radiography (ie, panoramic or periapical) and FDG PET/CT with 1-mm sections. Outcome variables for the radiographic findings were osteolytic and osteosclerotic bone changes. Outcome variables for FDG PET/CT images were localization of FDG uptake. Maximum standard uptake values (SUVmax) of abnormal FDG jaw uptake were recorded, in addition to the mean SUV of the contralateral normal mandible, and used to calculate the target-to-background ratio. Radiographic changes and FDG uptake were classified as local (ie, corresponding to exposed cortical bone) or diffuse (ie, local changes and changes extending beyond the margins of exposed bone) for each imaging technique. Local and diffuse changes detected by each imaging modality were described and the difference in detection was compared with the McNemar test. RESULTS: Twenty-three patients with 25 clinically identified ONJ lesions were analyzed using radiography and FDG PET/CT. Differences were found in how radiography and FDG PET/CT detect local and diffuse changes associated with ONJ. Radiography showed local changes in 17 patients (68%), diffuse changes in 3 patients (12%), and no changes in 5 patients (20%), whereas FDG PET/CT imaging showed local changes in 17 patients (68%) and diffuse changes in 8 patients (32%). The McNemar test indicated that FDG PET/CT imaging was less likely to miss a lesion (P < .001). Mean SUVmax was 6.59, and the mean target-to-background ratio was 5.37. CONCLUSION: The results of this study show that FDG PET/CT detects local and diffuse metabolic changes that may not be represented by plain radiography for patients with ONJ related to antiresorptive therapy. The target-to-background ratio allowed the discrimination between ONJ lesions and background changes. Future studies are necessary to determine whether FDG PET/CT can determine risk and facilitate management of ONJ.
Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/diagnóstico por imagem , Fluordesoxiglucose F18 , Doenças Mandibulares/induzido quimicamente , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Conservadores da Densidade Óssea/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Estudos Transversais , Difosfonatos/efeitos adversos , Feminino , Humanos , Imidazóis/efeitos adversos , Masculino , Mandíbula/diagnóstico por imagem , Doenças Mandibulares/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia Interproximal/métodos , Radiografia Panorâmica/métodos , Estudos Retrospectivos , Extração Dentária , Ácido ZoledrônicoRESUMO
PURPOSE: To assess diagnostic sensitivity of radial T1-weighted gradient-echo (radial volumetric interpolated breath-hold examination [VIBE]) magnetic resonance (MR) imaging, positron emission tomography (PET), and combined simultaneous PET and MR imaging with an integrated PET/MR system in the detection of lung nodules, with combined PET and computed tomography (CT) as a reference. MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant prospective study, 32 patients with tumors who underwent clinically warranted fluorine 18 ((18)F) fluorodeoxyglucose (FDG) PET/CT followed by PET/MR imaging were included. In all patients, the thorax station was examined with free-breathing radial VIBE MR imaging and simultaneously acquired PET data. Presence and size of nodules and FDG avidity were assessed on PET/CT, radial VIBE, PET, and PET/MR images. Percentage of nodules detected on radial VIBE and PET images was compared with that on PET/MR images by using generalized estimating equations. Maximum standardized uptake value (SUVmax) in pulmonary nodules with a diameter of at least 1 cm was compared between PET/CT and PET/MR imaging with Pearson rank correlation. RESULTS: A total of 69 nodules, including 45 FDG-avid nodules, were detected with PET/CT. The sensitivity of PET/MR imaging was 70.3% for all nodules, 95.6% for FDG-avid nodules, and 88.6% for nodules 0.5 cm in diameter or larger. PET/MR imaging had higher sensitivity than PET for all nodules (70.3% vs 61.6%, P = .002) and higher sensitivity than MR imaging for FDG-avid nodules (95.6% vs 80.0%, P = .008). There was a significantly strong correlation between SUVmax of pulmonary nodules obtained with PET/CT and that obtained with PET/MR imaging (r = 0.96, P < .001). CONCLUSION: Radial VIBE and PET data acquired simultaneously with PET/MR imaging have high sensitivity in the detection of FDG-avid nodules and nodules 0.5 cm in diameter or larger, with low sensitivity for small non-FDG-avid nodules.
Assuntos
Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Imageamento por Ressonância Magnética/estatística & dados numéricos , Imagem Multimodal/estatística & dados numéricos , Tomografia por Emissão de Pósitrons , Nódulo Pulmonar Solitário/diagnóstico , Nódulo Pulmonar Solitário/epidemiologia , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Prevalência , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: The purpose of this study was to determine if there is an association between necrosis as identified on staging (18)F-FDG PET/CT and overall survival (OS) and progression-free survival (PFS) in patients with sarcoma. MATERIALS AND METHODS: Sixty-six patients with newly diagnosed limb and girdle sarcoma underwent PET/CT at our institution between June 2004 and July 2009 for sarcoma staging before treatment with curative intent. The tumor maximum standardized up-take values (SUVmax), the presence of necrosis, and the volume of necrosis were measured for each primary tumor and correlated with follow-up data. PFS and OS were analyzed using the Kaplan-Meier method. Proportional hazards models were used to estimate hazard ratios. RESULTS: Median patient age was 49 years, and 51.6% of the patients were men. Sarcomas were categorized as soft tissue (69.2%), bone (23.5%), or other (7.3%). Mean follow-up time was 33.3 months. During the follow-up interval, 53% of patients experienced disease progression, and 40.9% died. There was a statistically significant relationship between the presence of necrosis and OS (by log-rank test, p = 0.001), as well as PFS (by log-rank test, p = 0.0001). Twenty-four-month OS was 96%, 65%, and 38% in patients with tumors with absence necrosis, those with presence of necrosis, and with necrosis volume greater than 50%, respectively. Forty-eight-month OS was 81% in patients with absence of necrosis and 41% in patients with presence of necrosis. Twelve-month PFS was 96%, 60%, and 42% in patients with tumors with absence of necrosis, those with presence of necrosis, and those with necrosis volume greater than 50%, respectively. Twenty-four-month PFS was 83%, 38%, and 22%, respectively, in these groups. CONCLUSION: The presence of necrosis and the volume of necrosis, as identified on the staging FDG PET/CT and after adjusting for SUVmax, are strong independent adverse prognostic factors for disease recurrence and death in patients with limb and girdle sarcomas.
Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/mortalidade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Sarcoma/diagnóstico por imagem , Sarcoma/mortalidade , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/mortalidade , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Neoplasias Ósseas/patologia , Progressão da Doença , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Compostos Radiofarmacêuticos , Sarcoma/patologia , Neoplasias de Tecidos Moles/patologia , Taxa de SobrevidaRESUMO
OBJECTIVE: The purpose of this study was to compare the accuracy of the spatial registration of conventional PET/CT with that of hybrid PET/MRI of patients with FDG-avid metastatic lesions. SUBJECTS AND METHODS: Thirteen patients with known metastatic lesions underwent FDG PET/CT followed by PET/MRI with a hybrid whole-body system. The inclusion criterion for tumor analysis was spherical or oval FDG-avid tumor clearly identified with both CT and MRI. The spatial coordinates (x, y, z) of the visually estimated centers of the lesions were determined for PET/CT (PET and CT independently) and PET/MRI (PET, T1-weighted gradient-echo sequence with radial stack-of-stars trajectory, T2-weighted sequence), and the b0 images of an echo-planar imaging (EPI) diffusion-weighted imaging (DWI) acquisition. All MRI sequences were performed in the axial plane with free breathing. The spatial coordinates of the estimated centers of the lesions were determined for PET and CT and PET and MRI sequences. Distance between the isocenter of the lesion on PET images and on the images obtained with the anatomic modalities was measured, and misregistration (in millimeters) was calculated. The degree of misregistration was compared between PET/CT and PET/MRI with a paired Student t test. RESULTS: Nineteen lesions were evaluated. On PET/CT images, the average of the total misregistration in all planes of CT compared with PET was 4.13 ± 4.24 mm. On PET/MR images, lesion misregistration between PET and T1-weighted gradient-echo images had a shift of 2.41 ± 1.38 mm and between PET and b0 DW images was 5.97 ± 2.83 mm. Similar results were calculated for 11 lesions on T2-weighted images. The shift on T2-weighted images compared with PET images was 2.24 ± 1.12 mm. Paired Student t test calculations for PET/CT compared with PET/MRI T1-weighted gradient-echo images with a radial stack-of-stars trajectory, b0 DW images, and T2-weighted images showed significant differences (p < 0.05). Similar results were seen in the analysis of six lung lesions. CONCLUSION: PET/MRI T1-weighted gradient-echo images with a radial stack-of-stars trajectory and T2-weighted images had more accurate spatial registration than PET/CT images. This may be because that the whole-body PET/MRI system used can perform simultaneous acquisition, whereas the PET/CT system acquires data sequentially. However, the EPI-based b0 DWI datasets were significantly misregistered compared with the PET/CT datasets, especially in the thorax. Radiologists reading PET/MR images should be aware of the potential for misregistration on images obtained with EPI-based DWI sequences because of inherent spatial distortion associated with this type of MRI acquisition.
Assuntos
Imagem Multimodal , Imagem Corporal Total , Idoso , Feminino , Fluordesoxiglucose F18 , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: The purpose of this study was to assess the correlation between standardized uptake value (SUV) and apparent diffusion coefficient (ADC) of neoplastic lesions in the use of a simultaneous PET/MRI hybrid system. SUBJECTS AND METHODS: Twenty-four patients with known primary malignancies underwent FDG PET/CT. They then underwent whole-body PET/MRI. Diffusion-weighted imaging was performed with free breathing and a single-shot spin-echo echo-planar imaging sequence with b values of 0, 350, and 750 s/mm(2). Regions of interest were manually drawn along the contours of neoplastic lesions larger than 1 cm, which were clearly identified on PET and diffusion-weighted images. Maximum SUV (SUVmax) on PET/MRI and PET/CT images, mean SUV (SUVmean), minimum ADC (ADCmin), and mean ADC (ADCmean) were recorded on PET/MR images for each FDG-avid neoplastic soft-tissue lesion with a maximum of three lesions per patient. Pearson correlation coefficient was used to asses the following relations: SUVmax versus ADCmin on PET/MR and PET/CT images, SUVmean versus ADCmean, and ratio of SUVmax to mean liver SUV (SUV ratio) versus ADCmin. A subanalysis of patients with progressive disease versus partial treatment response was performed with the ratio of SUVmax to ADCmin for the most metabolically active lesion. RESULTS: Sixty-nine neoplastic lesions (52 nonosseous lesions, 17 bone metastatic lesions) were evaluated. The mean SUVmax from PET/MRI was 7.0 ± 6.0; SUVmean, 5.6 ± 4.6; mean ADCmin, 1.10 ± 0.58; and mean ADCmean, 1.48 ± 0.72. A significant inverse Pearson correlation coefficient was found between PET/MRI SUVmax and ADCmin (r = -0.21, p = 0.04), between SUVmean and ADCmean (r = -0.18, p = 0.07), and between SUV ratio and ADCmin (r = -0.27, p = 0.01). A similar inverse Pearson correlation coefficient was found between the PET/CT SUVmax and ADCmin. Twenty of 24 patients had previously undergone PET/CT; five patients had a partial treatment response, and six had progressive disease according to Response Evaluation Criteria in Solid Tumors 1.1. The ratio between SUVmax and ADCmin was higher among patients with progressive disease than those with a partial treatment response. CONCLUSION: Simultaneous PET/MRI is a promising technology for the detection of neoplastic disease. There are inverse correlations between SUVmax and ADCmin and between SUV ratio and ADCmin. Correlation coefficients between SUVmax and ADCmin from PET/MRI were similar to values obtained with SUVmax from the same-day PET/CT. Given that both SUV and ADC are related to malignancy and that the correlation between the two biomarkers is relatively weak, SUV and ADC values may offer complementary information to aid in determination of prognosis and treatment response. The combined tumoral biomarker, ratio between SUVmax and ADCmin, may be useful for assessing progressive disease versus partial treatment response.
Assuntos
Imagem Multimodal , Neoplasias/diagnóstico , Imagem Corporal Total , Idoso , Imagem de Difusão por Ressonância Magnética , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: The objective of our study was to determine whether there is a statistically significant correlation between metabolic activity of osseous and soft-tissue sarcomas as measured by the maximum standardized uptake value (SUV(max)) on (18)F-FDG PET/CT and histopathologic characteristics such as mitotic counts, the presence of necrosis, and the presence of a myxoid component. MATERIALS AND METHODS: We retrospectively evaluated 238 consecutive patients with known soft-tissue or osseous sarcoma who underwent (18)F-FDG PET/CT for initial staging or assessment for recurrence of disease. The SUV(max) of each primary or of the most intense metastatic lesion was measured and was compared with the histologic data provided in the final pathology reports. RESULTS: Histopathologic data were available for 136 sarcomas. The median SUV(max) values of sarcomas with mitotic counts of less than 2.00 (per 10 high-power fields [HPF]), 2.00-6.99, 7.00-16.24, and 16.25 or greater were 5.0, 6.6, 10.3, and 13.0, respectively (p = 0.0003). The median SUV(max) for the sarcomas with necrosis (90 patients) was 8.6 and for those without necrosis (43 patients), 6.0 (p = 0.026). The median SUV(max) for the sarcomas without a myxoid component (118 patients) was 7.7 and with a myxoid component (16 patients) was 6.2 (p = 0.28). CONCLUSION: There was a statistically significant correlation between the mitotic count and the SUV(max) as well as between the presence of tumor necrosis and the SUV(max). Although a correlation between the presence of a myxoid component and SUV(max) was shown, it was not found to be statistically significant. These findings improve on the current information in the literature regarding the use of PET/CT for guidance in sarcoma biopsy. Correlating the SUV(max) with histologic markers that also feature prominently in major sarcoma grading systems may help improve the accuracy of grading and of prognostication by allowing the SUV(max) to potentially serve as a surrogate marker in these grading systems, particularly in cases in which there is interobserver disagreement in the pathologic diagnosis or in cases in which the sarcoma cannot be properly classified on the basis of histopathologic evaluation alone.
Assuntos
Imagem Multimodal , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/metabolismo , Tomografia por Emissão de Pósitrons , Sarcoma/diagnóstico por imagem , Sarcoma/metabolismo , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Estadiamento de Neoplasias , Osteossarcoma/patologia , Compostos Radiofarmacêuticos/farmacocinética , Estudos Retrospectivos , Sarcoma/patologia , Estatísticas não ParamétricasRESUMO
A 69-year-old woman who presented with left lower quadrant abdominal pain and elevated serum cancer antigen 125 (CA-125) levels was referred for an MRI and an (18)F-FDG PET/CT to evaluate a suspicious abdominal mass seen on ultrasound. PET/CT showed extensive, intensely FDG-avid, omental and pelvic peritoneal thickening with no suspicious ovarian or colon masses. Based on the PET/CT results, the patient had extensive debulking surgery and histopathological evaluation revealed an extraovarian primary peritoneal carcinoma (EOPPC). (18)F-FDG PET/CT may be useful in differentiating EOPPC from other types of peritoneal carcinomatosis, and in determining the extent of the disease to better guide surgical management and improve long term outcomes.
Assuntos
Neoplasias dos Genitais Femininos/patologia , Imagem Multimodal , Neoplasias Peritoneais/patologia , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Idoso , Diagnóstico Diferencial , Feminino , Fluordesoxiglucose F18 , Neoplasias dos Genitais Femininos/diagnóstico por imagem , Neoplasias dos Genitais Femininos/cirurgia , Humanos , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias Peritoneais/diagnóstico por imagem , Neoplasias Peritoneais/cirurgia , Compostos RadiofarmacêuticosRESUMO
Disseminated histoplasmosis is an opportunistic infection encountered in immunocompromised patients such as those with human immunodeficiency virus infection/acquired immune deficiency syndrome. Involvement of the central nervous system (CNS) can occur in 5-20% of cases of disseminated histoplasmosis, and CNS histoplasmosis can be very difficult to diagnose via conventional imaging modalities such as CT or MRI. The role of 18F-fludeoxyglucose positron emission tomography/CT scan in the diagnosis of CNS histoplasmosis has not been established. A 66-year-old female presented with dizziness and unsteady gait and was diagnosed with human immunodeficiency virus infection and CNS histoplasmosis. In this report, we present the MRI and 18F-fludeoxyglucose positron emission tomography/CT image findings.
RESUMO
A 75-year-old woman presented with a 1-year history of an enlarging mass in the left parotid gland. Biopsy revealed a parotid plasmacytoma, and the patient was referred for a staging F-FDG PET/CT to evaluate the presence of multiple myeloma bone involvement. The PET/CT scan showed intense FDG uptake in the neck mass but no FDG-avid lymphadenopathy or distant metastases. Plasmacytoma involving the parotid gland is extremely rare. We present the F-FDG PET/CT imaging of solitary parotid plasmacytoma.
Assuntos
Fluordesoxiglucose F18 , Glândula Parótida/patologia , Plasmocitoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Neoplasias das Glândulas Salivares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Glândula Parótida/diagnóstico por imagemRESUMO
A 44-year-old woman with recurrent parathyroid carcinoma (PTC) presents with moderately elevated parathyroid hormone and ionized calcium levels. Dual-phase Tc-MIBI SPECT study of the neck and chest demonstrated 2 new foci in keeping with neoplastic seeding. A restaging whole-body F-FDG PET/CT showed no evidence of FDG uptake in the region of the MIBI-positive foci or any evidence of distant metastases. The role of F-FDG PET/CT for imaging PTC is still somewhat limited because of the rarity of this disease. We present a case highlighting a potential pitfall for FDG PET in detecting PTC.
Assuntos
Fluordesoxiglucose F18 , Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Tecnécio Tc 99m Sestamibi , Adulto , Feminino , Humanos , Esvaziamento Cervical , Recidiva Local de Neoplasia/cirurgia , Neoplasias das Paratireoides/cirurgia , CintilografiaRESUMO
Simultaneous positron emission tomography (PET)/magnetic resonance (MR) imaging is a promising novel technology for oncology diagnosis and staging and neurologic and cardiac applications. Our institution's current research protocol results in a total imaging time of approximately 45 to 70 minutes with simultaneous PET/MR imaging, making this a feasible total body imaging protocol. Further development of MR-based attenuation correction will improve PET quantification. Quantitatively accurate multiparametric PET/MR data sets will likely improve diagnosis of disease and help guide and monitor the therapies for individualized patient care.
Assuntos
Fluordesoxiglucose F18 , Imageamento por Ressonância Magnética/tendências , Imagem Multimodal/tendências , Tomografia por Emissão de Pósitrons/tendências , Compostos Radiofarmacêuticos , Desenho de Equipamento/tendências , Previsões , Humanos , Imageamento por Ressonância Magnética/instrumentação , Imagem Multimodal/instrumentação , Neoplasias/diagnóstico , Doenças do Sistema Nervoso/diagnóstico , Tomografia por Emissão de Pósitrons/instrumentação , Lesões por Radiação/etiologia , Planejamento da Radioterapia Assistida por Computador , Fatores de RiscoRESUMO
A 69-year-old woman presented with a spontaneous right subtrochanteric hip fracture. Pan-imaging following orthopedic repair failed to identify a primary malignancy to explain the presumed pathologic basis for this fracture. The patient then underwent bone scintigraphy and SPECT/CT which showed mild uptake in multifocal endosteal thickening of the lateral left femoral diaphysis, diagnostic of bisphosphonate-associated femoral shaft stress fractures, but no evidence of metastatic bone disease. Atypical bisphosphonate-associated subtrochanteric and femoral shaft stress fractures have a fairly specific appearance on bone scintigraphy, and nuclear medicine physicians should be aware of this relatively infrequent emerging pathology.
Assuntos
Difosfonatos/efeitos adversos , Fêmur/diagnóstico por imagem , Fraturas de Estresse/induzido quimicamente , Fraturas de Estresse/diagnóstico por imagem , Fraturas do Quadril/induzido quimicamente , Fraturas do Quadril/diagnóstico por imagem , Quadril/diagnóstico por imagem , Idoso , Feminino , Fêmur/efeitos dos fármacos , Humanos , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios XRESUMO
A 28-year-old woman with a history of prior bilateral retinoblastoma presented with general fatigue, anemia, and a urinary bladder mass seen on abdominal ultrasound and CT. She was referred for a staging 18F-FDG PET/CT, which showed an intensely FDG-avid bladder mass that was biopsied to reveal a leiomyosarcoma, with no evidence of metastases, which guided her management. 18F-FDG PET/CT is routinely used in the evaluation of leiomyosarcomas; however, its use in the staging of a leiomyosarcoma of the urinary bladder has not been previously described in the literature. This case highlights the usefulness of PET/CT in the staging of this rare tumor.
Assuntos
Fluordesoxiglucose F18 , Leiomiossarcoma/diagnóstico por imagem , Leiomiossarcoma/patologia , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Adulto , Feminino , Humanos , Estadiamento de NeoplasiasRESUMO
Tetrasomy 8 is a relatively rare chromosomal abnormality that has been reported in only 33 cases in hematologic disorders. It is known for its association with aggressive acute myeloid leukemia (AML) and myeloid sarcoma and is considered a very poor prognostic factor. Myeloid sarcoma is a rare hematologic malignancy characterized by tumor masses consisting of immature myeloid cells, presenting at an extramedullary site. We present a case of a 17-year-old boy referred for an (18)F-FDG PET/CT for the evaluation of pleural masses and spinal bone lesions seen on CT, after presenting with a 4 month history of chest pain. The PET/CT revealed extensive FDG-avid extramedullary disease in the soft tissues of the chest, abdomen, and pelvis, which were biopsy-proven to be myeloid sarcoma, as well as extensive intramedullary disease biopsy proven to be AML. This is the first report of the use of (18)F-FDG PET/CT to stage a subset of aggressive AML and myeloid sarcoma in a patient with an associated chromosomal abnormality (tetrasomy 8).
RESUMO
A 29-year-old male presented with a 6-month history of left hip pain. Radiography and CT demonstrated a 6-cm lytic lesion of the left acetabulum. F-18 FDG PET for staging of the biopsy-proven malignant PEComa demonstrated intense hypermetabolism corresponding to the lytic left acetabulum. The patient underwent left hemipelvectomy with reconstructive surgery. On a follow-up F-18 FDG PET scan 3 months after initial surgery, a left lung pleural-based 9-mm nodule with hypermetabolism (SUVmax 4.1) was discovered and pathologically proven to be metastases from the primary osseous PEComa.
Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Fluordesoxiglucose F18 , Imagem Multimodal , Neoplasias de Células Epitelioides Perivasculares/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Neoplasias Ósseas/patologia , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Masculino , Neoplasias de Células Epitelioides Perivasculares/patologiaRESUMO
A wide variety of malignant renal and urinary bladder diseases can be detected on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas was to demonstrate that the spectrum of renal and urinary bladder malignancy that can be evaluated with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the variety of urological tumor types that can be detected on PET/CT and some of the patterns of (18)F-FDG uptake that can be observed in these cases.
Assuntos
Fluordesoxiglucose F18 , Aumento da Imagem/métodos , Neoplasias Renais/diagnóstico , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Neoplasias da Bexiga Urinária/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos RadiofarmacêuticosRESUMO
A 20-year-old woman, who presented with a several-week history of abdominal pain, was referred for magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) after an ultrasound showed complex cystic masses arising from both ovaries. The MRI and (18)F-FDG PET/CT imaging characteristics of the ovarian masses were strongly suspicious for malignancy, and the masses were surgically removed. Histopathological evaluation revealed a bilateral tubo-ovarian abscess, with no evidence of malignancy. This case highlights a potentially serious pitfall in the evaluation of suspicious pelvic masses by (18)F-FDG PET/CT, whereby a complex bilateral tubo-ovarian abscess may mimic the PET/CT imaging characteristics of an ovarian or pelvic malignancy.
RESUMO
BACKGROUND: Brown adipose tissue (BAT) activity on (18)F-fluorodeoxyglucose (FDG) PET/CT can introduce an undesirable element of complexity when attempting to discern physiologic activity from more ominous entities. Recent studies have demonstrated several methods to reduce BAT FDG uptake. Benzodiazepines, however, have yet to been proven effective against BAT. METHODS: Twenty-five patients with increased BAT FDG uptake were selected retrospectively from our PET/CT database between November 2004 and January 2011. These patients had been asked to return on a different day for repeat scanning with 5mg of intravenous diazepam, administered ten minutes prior to FDG. Two patients underwent this procedure on a second occasion (for a follow-up scan at a later date), thus resulting in a total of twenty-seven scans from twenty five patients. FDG uptake in BAT was recorded using the maximum standardized uptake value (SUVmax). RESULTS: The mean basal BAT SUVmax was 10.1 ± 4.6 compared to a mean SUVmax of 2.8 ± 3.3 post IV diazepam (p < 0.0001). Approximately 89% (24 of 27) of scans had no significant residual BAT activity. The three remaining scans had a reduction in SUVmax ranging from 23-64% following diazepam administration. No adverse effects were noted. CONCLUSION: We observed a significant reduction in brown fat activity in para-spinal, cervical, mediastinal, para-adrenal, and supra- and infra-clavicular regions on PET/CT following premedication with intravenous diazepam. We feel that IV benzodiazepines should be considered a pharmacologic option for reducing BAT FDG uptake, which in turn, will aid in distinguishing physiologic metabolic activity from pathology.