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1.
Nat Commun ; 10(1): 4673, 2019 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-31611594

RESUMO

Advances in precision molecular imaging promise to transform our ability to detect, diagnose and treat disease. Here, we describe the engineering and validation of a new cystine knot peptide (knottin) that selectively recognizes human integrin αvß6 with single-digit nanomolar affinity. We solve its 3D structure by NMR and x-ray crystallography and validate leads with 3 different radiolabels in pre-clinical models of cancer. We evaluate the lead tracer's safety, biodistribution and pharmacokinetics in healthy human volunteers, and show its ability to detect multiple cancers (pancreatic, cervical and lung) in patients at two study locations. Additionally, we demonstrate that the knottin PET tracers can also detect fibrotic lung disease in idiopathic pulmonary fibrosis patients. Our results indicate that these cystine knot PET tracers may have potential utility in multiple disease states that are associated with upregulation of integrin αvß6.


Assuntos
Antígenos de Neoplasias/metabolismo , Fibrose Pulmonar Idiopática/diagnóstico , Integrinas/metabolismo , Neoplasias/diagnóstico , Cristalografia por Raios X , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Tomografia por Emissão de Pósitrons
2.
Br J Radiol ; 92(1094): 20180336, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30307319

RESUMO

OBJECTIVE:: In acute gastrointestinal bleeding, despite positive dynamic phase 99mTc-red blood cell scintigraphy, invasive catheter angiography (CA) is frequently negative. In this study, we investigated the value of flow phase scintigraphy in predicting extravasation on CA. METHODS:: Institutional review board approval with a waiver of informed consent was obtained for this retrospective study. A total of 173 scintigraphy procedures performed in 145 patients with GIB between January 2013 and August 2014 were analysed. Scintigraphy had two phases: flow (1 image/s for 1 min) followed by dynamic (1 image/30 s for 1 h). Patients who underwent CA within 24 hours of positive scintigraphy were assessed. Each scintigraphy phase was randomly and independently reviewed by two nuclear medicine physicians blinded to the outcomes of the other phase and of CA. RESULTS:: A total of 42 patients (29%) had positive scintigraphy. Of these patients, 29 underwent CA, and extravasation was seen in 6 (21%). In all, dynamic phase scintigraphy was positive. 13 of the 29 patients also had positive flow phase scintigraphy. The sensitivity, specificity, positive-predictive value, and negative-predictive value of flow phase scintigraphy for extravasation on CA were 100, 70, 46, and 100%, respectively. Specificity and positive predictive value were higher when CA was performed within 4 hours of positive flow phase scintigraphy. CONCLUSIONS:: Negative flow phase scintigraphy can identify patients who will not benefit from CA despite positive dynamic phase scintigraphy. The likelihood of extravasation on CA is higher when performed soon after positive flow phase scintigraphy. ADVANCES IN KNOWLEDGE:: Negative flow phase scintigraphy identifies patients who will not benefit from invasive catheter angiography despite positive results on subsequent dynamic phase scintigraphy. Increasing the delay between positive red blood cell scintigraphy and catheter angiography progressively reduces the likelihood of identifying extravasation, which is required to target embolization.


Assuntos
Angiografia , Hemorragia Gastrointestinal/diagnóstico por imagem , Cintilografia/métodos , Compostos Radiofarmacêuticos , Tecnécio , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Eritrócitos , Extravasamento de Materiais Terapêuticos e Diagnósticos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Método Simples-Cego , Adulto Jovem
3.
Radiology ; 290(3): 649-656, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30526350

RESUMO

Purpose To reduce radiotracer requirements for amyloid PET/MRI without sacrificing diagnostic quality by using deep learning methods. Materials and Methods Forty data sets from 39 patients (mean age ± standard deviation [SD], 67 years ± 8), including 16 male patients and 23 female patients (mean age, 66 years ± 6 and 68 years ± 9, respectively), who underwent simultaneous amyloid (fluorine 18 [18F]-florbetaben) PET/MRI examinations were acquired from March 2016 through October 2017 and retrospectively analyzed. One hundredth of the raw list-mode PET data were randomly chosen to simulate a low-dose (1%) acquisition. Convolutional neural networks were implemented with low-dose PET and multiple MR images (PET-plus-MR model) or with low-dose PET alone (PET-only) as inputs to predict full-dose PET images. Quality of the synthesized images was evaluated while Bland-Altman plots assessed the agreement of regional standard uptake value ratios (SUVRs) between image types. Two readers scored image quality on a five-point scale (5 = excellent) and determined amyloid status (positive or negative). Statistical analyses were carried out to assess the difference of image quality metrics and reader agreement and to determine confidence intervals (CIs) for reading results. Results The synthesized images (especially from the PET-plus-MR model) showed marked improvement on all quality metrics compared with the low-dose image. All PET-plus-MR images scored 3 or higher, with proportions of images rated greater than 3 similar to those for the full-dose images (-10% difference [eight of 80 readings], 95% CI: -15%, -5%). Accuracy for amyloid status was high (71 of 80 readings [89%]) and similar to intrareader reproducibility of full-dose images (73 of 80 [91%]). The PET-plus-MR model also had the smallest mean and variance for SUVR difference to full-dose images. Conclusion Simultaneously acquired MRI and ultra-low-dose PET data can be used to synthesize full-dose-like amyloid PET images. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Catana in this issue.


Assuntos
Compostos de Anilina/administração & dosagem , Encefalopatias/diagnóstico por imagem , Aprendizado Profundo , Imagem por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Estilbenos/administração & dosagem , Idoso , Doença de Alzheimer/diagnóstico por imagem , Amiloide/análise , Disfunção Cognitiva/diagnóstico por imagem , Feminino , Humanos , Doença por Corpos de Lewy/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Transtornos Parkinsonianos/diagnóstico por imagem , Estudos Retrospectivos
4.
EJNMMI Phys ; 5(1): 9, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29666972

RESUMO

BACKGROUND: A newly introduced PET/CT scanner (Discovery Meaningful Insights-DMI, GE Healthcare) includes the silicon photomultiplier (SiPM) with time-of-flight (TOF) technology first used in the GE SIGNA PET/MRI. In this study, we investigated the impact of various acquisition times on image quality using this SiPM-based PET/CT. METHODS: We reviewed data from 58 participants with cancer who were scanned using the DMI PET/CT scanner. The administered dosages ranged 295.3-429.9 MBq (mean ± SD 356.3 ± 37.4) and imaging started at 71-142 min (mean ± SD 101.41 ± 17.52) after administration of the radiopharmaceutical. The patients' BMI ranged 19.79-46.16 (mean ± SD 26.55 ± 5.53). We retrospectively reconstructed the raw TOF data at 30, 60, 90, and 120 s/bed and at the standard image acquisition time per clinical protocol (180 or 210 s/bed depending on BMI). Each reconstruction was reviewed blindly by two nuclear medicine physicians and scored 1-5 (1-poor, 5-excellent quality). The liver signal-to-noise ratio (SNR) was used as a quantitative measure of image quality. RESULTS: The average scores ± SD of the readers were 2.61 ± 0.83, 3.70 ± 0.92, 4.36 ± 0.82, 4.82 ± 0.39, and 4.91 ± 0.91 for the 30, 60, 90, and 120 s/bed and at standard acquisition time, respectively. Inter-reader agreement on image quality assessment was good, with a weighted kappa of 0.80 (95% CI 0.72-0.81). In the evaluation of the effects of time per bed acquisition on semi-quantitative measurements, we found that the only time point significantly different from the standard time were 30 and 60 s (both with P < 0.001). The effects of dose and BMI were not statistically significant (P = 0.195 and 0.098, respectively). There was a significant positive effect of time on SNR (P < 0.001), as well as a significant negative effect of weight (P < 0.001). CONCLUSIONS: Our results suggest that despite significant delays from injection to imaging (due to comparison with standard PET/CT) compared to standard clinical operations and even in a population with average BMI > 25, images can be acquired as fast as 90 s/bed using the SiPM PET/CT and still result in very good image quality (average score > 4).

5.
PLoS One ; 12(6): e0178936, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28582472

RESUMO

PURPOSE: To evaluate if the new Discovery Molecular Insights (DMI) PET/CT scanner provides equivalent results compared to the standard of care PET/CT scanners (GE Discovery 600 or GE Discovery 690) used in our clinic and to explore any possible differences in semi-quantitative measurements. METHODS: The local Institutional Review Board approved the protocol and written informed consent was obtained from each patient. Between September and November 2016, 50 patients underwent a single 18F-FDG injection and two scans: the clinical standard PET/CT followed immediately by the DMI PET/CT scan. We measured SUVmax and SUVmean of different background organs and up to four lesions per patient from data acquired using both scanners. RESULTS: DMI PET/CT identified all the 107 lesions detected by standard PET/CT scanners, as well as additional 37 areas of focal increased 18F-FDG uptake. The SUVmax values for all 107 lesions ranged 1.2 to 14.6 (mean ± SD: 2.8 ± 2.8), higher on DMI PET/CT compared with standard of care PET/CT. The mean lesion:aortic arch SUVmax ratio and mean lesion:liver SUVmax ratio were 0.2-15.2 (mean ± SD: 3.2 ± 2.6) and 0.2-8.5 (mean ± SD: 1.9 ± 1.4) respectively, higher on DMI PET/CT than standard PET/CT. These differences were statistically significant (P value < 0.0001) and not correlated to the delay in acquisition of DMI PET data (P < 0.0001). CONCLUSIONS: Our study shows high performance of the new DMI PET/CT scanner. This may have a significant role in diagnosing and staging disease, as well as for assessing and monitoring responses to therapies.


Assuntos
Fluordesoxiglucose F18/farmacocinética , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/instrumentação , Compostos Radiofarmacêuticos/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Aorta/diagnóstico por imagem , Aorta/patologia , Feminino , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Dispositivos Ópticos , Projetos Piloto , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Sarcoidose/diagnóstico por imagem , Sarcoidose/patologia , Silício , Neoplasias Tonsilares/diagnóstico por imagem , Neoplasias Tonsilares/patologia
6.
J Gastrointest Oncol ; 7(4): 530-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27563442

RESUMO

BACKGROUND: Given the differences in size, specific activity, and dosing methods for glass yttrium-90 microspheres ((90)Y-glass) and resin (90)Y microspheres ((90)Y-resin), these therapies may expose the liver to different amounts of radiation, thereby affecting their efficacy and tolerability. We aimed to compare the prescribed activity of (90)Y-glass and (90)Y-resin for real-world patients undergoing selective internal radiation therapy (SIRT) for liver-dominant metastatic colorectal cancer (mCRC) and to assess efficacy and safety outcomes in these patients. METHODS: We examined the records of 28 consecutive patients with unresectable colorectal liver metastases treated with SIRT between June 2008 and May 2011 at our institution. Using baseline CT and MR images, we calculated a projected activity as if we had used the other product and compared it to the actual prescribed activity of (90)Y-glass and (90)Y-resin for each SIRT treatment per manufacturer guidelines. Progression and adverse events were evaluated at follow up visits. Survival was analyzed by the Kaplan-Meier method. RESULTS: For (90)Y-glass treatments with a mean prescribed (90)Y activity of 1.77 GBq, the mean projected (90)Y-resin activity was 0.84 GBq. For (90)Y-resin treatments with a mean prescribed (90)Y activity of 1.05 GBq, the mean projected (90)Y-glass activity was 2.48 GBq. The median survival was 9.3 months versus 18.2 months for (90)Y-glass and (90)Y-resin, respectively (P=0.292). During the second year after SIRT, the hazard ratio of death for patients treated with (90)Y-glass versus (90)Y-resin was 4.0 (95% CI: 1.3, 12.3; P=0.017). No significant difference in progression, adverse events or liver toxicity was observed. CONCLUSIONS: Using manufacturer recommended guidelines, (90)Y-resin delivers significantly less activity than (90)Y-glass to patients with liver-dominant mCRC undergoing SIRT with no significant difference in adverse events and a trend toward improved survival.

7.
Eur J Nucl Med Mol Imaging ; 42(12): 1840-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26136164

RESUMO

PURPOSE: Hypoxia is an important factor influencing tumor progression and treatment efficacy. The aim of this study was to investigate the repeatability of hypoxia PET imaging with [(18)F]HX4 in patients with head and neck and lung cancer. METHODS: Nine patients with lung cancer and ten with head and neck cancer were included in the analysis (NCT01075399). Two sequential pretreatment [(18)F]HX4 PET/CT scans were acquired within 1 week. The maximal and mean standardized uptake values (SUVmax and SUVmean) were defined and the tumor-to-background ratios (TBR) were calculated. In addition, hypoxic volumes were determined as the volume of the tumor with a TBR >1.2 (HV1.2). Bland Altman analysis of the uptake parameters was performed and coefficients of repeatability were calculated. To evaluate the spatial repeatability of the uptake, the PET/CT images were registered and a voxel-wise comparison of the uptake was performed, providing a correlation coefficient. RESULTS: All parameters of [(18)F]HX4 uptake were significantly correlated between scans: SUVmax (r = 0.958, p < 0.001), SUVmean (r = 0.946, p < 0.001), TBRmax (r = 0.962, p < 0.001) and HV1.2 (r = 0.995, p < 0.001). The relative coefficients of repeatability were 15 % (SUVmean), 17 % (SUVmax) and 17 % (TBRmax). Voxel-wise analysis of the spatial uptake pattern within the tumors provided an average correlation of 0.65 ± 0.14. CONCLUSION: Repeated hypoxia PET scans with [(18)F]HX4 provide reproducible and spatially stable results in patients with head and neck cancer and patients with lung cancer. [(18)F]HX4 PET imaging can be used to assess the hypoxic status of tumors and has the potential to aid hypoxia-targeted treatments.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Nitroimidazóis , Tomografia por Emissão de Pósitrons , Triazóis , Idoso , Transporte Biológico , Hipóxia Celular , Feminino , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Nitroimidazóis/metabolismo , Estudos Prospectivos , Reprodutibilidade dos Testes , Triazóis/metabolismo
8.
Front Oncol ; 4: 255, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25353006

RESUMO

BACKGROUND: Radioembolization with Yttrium-90 ((90) Y) microspheres is becoming a more widely used transcatheter treatment for unresectable hepatocellular carcinoma (HCC). Using post-treatment (90) Y positron emission tomography/computerized tomography (PET/CT) scans, the distribution of microspheres within the liver can be determined and quantitatively assessed. We studied the radiation dose of (90) Y delivered to liver and treated tumors. METHODS: This retrospective study of 56 patients with HCC, including analysis of 98 liver tumors, measured and correlated the dose of radiation delivered to liver tumors and normal liver tissue using glass microspheres (TheraSpheres(®)) to the frequency of complications with modified response evaluation criteria in solid tumors (mRECIST). (90) Y PET/CT and triphasic liver CT scans were used to contour treated tumor and normal liver regions and determine their respective activity concentrations. An absorbed dose factor was used to convert the measured activity concentration (Bq/mL) to an absorbed dose (Gy). RESULTS: The 98 studied tumors received a mean dose of 169 Gy (mode 90-120 Gy; range 0-570 Gy). Tumor response by mRECIST criteria was performed for 48 tumors that had follow-up scans. There were 21 responders (mean dose 215 Gy) and 27 non-responders (mean dose 167 Gy). The association between mean tumor absorbed dose and response suggests a trend but did not reach statistical significance (p = 0.099). Normal liver tissue received a mean dose of 67 Gy (mode 60-70 Gy; range 10-120 Gy). There was a statistically significant association between absorbed dose to normal liver and the presence of two or more severe complications (p = 0.036). CONCLUSION: Our cohort of patients showed a possible dose-response trend for the tumors. Collateral dose to normal liver is non-trivial and can have clinical implications. These methods help us understand whether patient adverse events, treatment success, or treatment failure can be attributed to the dose that the tumor or normal liver received.

9.
J Med Imaging Radiat Sci ; 45(4): 435-439, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31051916

RESUMO

PURPOSE: This study developed and tested a novel scanner constructed for dedicated positron emission tomography (PET) of the breast. The breast PET (B-PET) scanner is designed with two opposing detectors using curve plate NaI(Tl) detectors to achieve a combination of high spatial resolution and energy resolution. METHODS: Phantom and clinical studies (n = 20) with 18F-fluorodeoxyglucose were carried out on the whole-body Philips Allegro scanner and the B-PET scanner. Images were subjectively assessed by an expert panel. RESULTS: Phantom studies indicated improved contrast for B-PET over conventional PET. Of the 20 clinical studies with breast cancer demonstrated on whole-body fluorodeoxyglucose PET, 10 B-PET scans showed agreement. Of the remaining 10 studies, three had breasts that were too small to be imaged, four had lesions that were too deep to be captured in the field of view, and three were excluded due to technical errors. CONCLUSIONS: Compared with conventional PET, B-PET images provided greater detail in breast lesions suggesting that the low-cost and relatively simple design of B-PET may potentially be an important adjunct to traditional mammography in helping determine the nature of a lesion.

11.
Am J Otolaryngol ; 33(3): 289-95, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21925763

RESUMO

OBJECTIVE: The objective of the study is to examine the utility of positron emission tomography (PET) for staging and restaging after treatment of paranasal sinus carcinomas. STUDY DESIGN: Retrospective data review was done. SUBJECTS AND METHODS: Patients selected underwent PET for sinonasal neoplasms from 2003 to 2008 at a tertiary care referral center. RESULTS: Seventy-seven scans were reviewed from 31 patients. The pathologies included olfactory neuroblastoma (n = 9), squamous cell carcinoma (n = 6), sinonasal undifferentiated carcinoma (n = 6), sinonasal melanoma (n = 6), and minor salivary gland carcinomas (n = 4). The positive predictive value of studies performed for restaging at the primary, neck, and distant sites were 56%, 54%, and 63%; negative predictive values were 93%, 100%, and 98%, respectively. During restaging, 32% of patients were accurately upstaged secondary to neck or distant site involvement. CONCLUSION: Positron emission tomography serves as a useful adjunct to conventional imaging in the management of sinonasal malignancies. Negative studies are effective in predicting absence of disease as seen in the consistently high-negative predictive values. Positive studies need to be viewed cautiously given the high rate of false-positive studies. When viewed in conjunction with clinical examination, endoscopic assessment, and focused biopsies, they may effectively result in a more accurate assessment of the extent of disease.


Assuntos
Neoplasias dos Seios Paranasais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Terapia Combinada , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Linfonodos/diagnóstico por imagem , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Pescoço , Estadiamento de Neoplasias/métodos , Neoplasias dos Seios Paranasais/secundário , Neoplasias dos Seios Paranasais/terapia , Reprodutibilidade dos Testes , Estudos Retrospectivos
13.
J Vasc Interv Radiol ; 22(12): 1697-705, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21983055

RESUMO

PURPOSE: To compare retrospectively the safety and efficacy of yttrium-90 ((90)Y) radioembolization with the safety and efficacy of chemoembolization in patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Survival and complication rates were evaluated for patients with HCC who underwent chemoembolization or radioembolization at a single institution between August 2007 and April 2010. Complications were graded according to a standardized grading system for embolization procedures. Survival was determined via the Kaplan-Meier method, and multivariable analysis for factors affecting survival was performed. RESULTS: This study included 73 patients with HCC who underwent index embolization with radioembolization (n = 38; 52.1%) or chemoembolization (n = 35; 47.9%). The two patient populations were similar in terms of demographics, etiology of cirrhosis, functional status, tumor characteristics, Child-Pugh class, previous liver-directed therapy, and number of patients with bilirubin > 2.0 mg/dL. There was no significant difference in survival between the radioembolization (median 8.0 months) and chemoembolization (median 10.3 months) cohorts (P = .33). Postembolization syndrome was significantly more severe in patients who underwent chemoembolization, which led to increased total hospitalization rates in these patients. The rates of other complications and rehospitalization were similar between groups. Increased age, Child-Pugh class B, hepatitis seropositivity, bilobar tumor distribution, tumor vascular invasion, and presence of extrahepatic metastases were associated with reduced patient survival. CONCLUSIONS: Patients treated with radioembolization did not show a survival advantage over patients treated with chemoembolization. However, patients who underwent chemoembolization had significantly higher rates of hospitalization as a result of postembolization syndrome.


Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/mortalidade , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/terapia , Radioterapia/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Hepatectomia/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Lesões por Radiação/mortalidade , Compostos Radiofarmacêuticos/uso terapêutico , Medição de Risco , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia , Radioisótopos de Ítrio/uso terapêutico
14.
PET Clin ; 6(2): 195-205, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27156590

RESUMO

In addition to allowing much greater technical precision, the modern era allows investigation of target physiology and it is the potential incorporation of physiologic information into the treatment-planning rubric that gives modern PET-CT its allure and promise. Although oncologic PET scanning has been clinically available for more than 10 years, it is only recently that sufficient investigative and retrospective data have become available to confidently assert that future radiotherapy treatment planning will include functional imaging as an obligatory dimension of clinical characterization for most gynecologic tumors. This article explores the role of functional imaging in radiotherapy planning and management of gynecologic malignancies.

15.
Radiother Oncol ; 100(2): 293-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20951451

RESUMO

PURPOSE: The goal of this study was to determine the feasibility of SPECT/CT scintigraphic method for mapping lymphatic drainage for radiation therapy of breast cancer. MATERIALS AND METHODS: Thirty-six patients were enrolled in a SPECT/CT lymphoscintigraphy study. (99m)Tc sulfur colloid (1mCi) was injected intradermally in the ipsilateral arm. After 5-8h post-injection, the SPECT/CT scans were taken and analyzed on a GE eNTRGRA system. The SPECT/CT images were co-registered in the treatment planning system (TPS). The original treatment plan was recreated for nodal dosimetry. Intensity modulated radiation therapy (IMRT) planning was performed for reducing lymph node dose for reducing arm lymphedema. RESULTS: The number of lymph nodes varied from 0 to 10 with a mean value of 3.4±5.4 nodes. The location of nodes varied in the axillary, supraclavicular, and breast regions depending upon the surgical procedure and the extent of the disease. The prescribed radiation dose to the breast varied from 45 to 50.4Gy depending on the disease pattern in 32 evaluated patients having CT data. The dose to lymph nodes varied from 0 to 61.8Gy depending upon the location and the radiation technique used. SPECT/CT study in conjunction with IMRT plan showed that it is possible to decrease nodal dose and thereby potentially reduce the risk of developing arm lymphedema. CONCLUSIONS: The SPECT/CT device provides a novel method to map the lymph nodes in the radiation treatment fields that could be used to tailor the radiation dose.


Assuntos
Neoplasias da Mama/radioterapia , Linfedema/prevenção & controle , Linfocintigrafia , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Biópsia de Linfonodo Sentinela , Tomografia Computadorizada por Raios X , Drenagem , Feminino , Humanos , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada
16.
Int J Radiat Oncol Biol Phys ; 78(4): 1033-9, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20472359

RESUMO

PURPOSE: To perform a retrospective review to determine whether maximum standardized uptake values (SUV(max)) from staging 2-deoxy-2- [(18)F] fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) studies are associated with outcomes for early-stage non-small-cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). METHODS AND MATERIALS: Seventy-two medically inoperable patients were treated between October 17, 2003 and August 17, 2007 with SBRT for T1-2N0M0 NSCLC. SBRT was administered as 60 Gy in 3 fractions, 50 Gy in 5 fractions, or 50 Gy in 10 fractions using abdominal compression and image-guided SBRT. Cox proportional hazards regression was performed to determine whether PET SUV(max) and other variables influenced outcomes: mediastinal failure (MF), distant metastases (DM), and overall survival (OS). RESULTS: Biopsy was feasible in 49 patients (68.1%). Forty-nine patients had T1N0 disease, and 23 had T2N0 disease. Median SUV(max) was 6.55 (range, 1.5-21). Median follow-up was 16.9 months (range, 0.1-37.9 months). There were 3 local failures, 8 MF, 19 DM, and 30 deaths. Two-year local control, MF, DM, and OS rates were 94.0%, 10.4%, 30.1%, and 61.3%, respectively. In univariate analysis, PET/CT SUV(max), defined either as a continuous or dichotomous variable, did not predict for MF, DM, or OS. On multivariable analysis, the only predictors for overall survival were T1 stage (hazard ratio = 0.331 [95% confidence interval, 0.156-0.701], p = 0.0039) and smoking pack-year history (hazard ratio = 1.015 [95% confidence interval, 1.004-1.026], p = 0.0084). CONCLUSIONS: Pretreatment PET SUV(max) did not predict for MF, DM, or OS in patients treated with SBRT for early-stage NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Fluordesoxiglucose F18 , Neoplasias Pulmonares/diagnóstico por imagem , Compostos Radiofarmacêuticos , Radiocirurgia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Pulmão/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Dosagem Radioterapêutica , Análise de Regressão , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
17.
Hell J Nucl Med ; 12(3): 218-22, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19936331

RESUMO

Fluorine-18 fluorodeoxyglycose -position emission tomography ((18)F-FDG-PET) as an efficient staging tool for lung carcinoma; allows description and characterization of the primary tumor and of local and distant metastases in a single examination. One of the important limiting factors in quantification of metabolic parameters with PET is the partial volume effect. Our aim for this study was to delineate tumor (size) both in the primary and metastatic lesions in patients with lung cancer by using partial volume correction techniques. Thirty two patients with proven lung cancer who had (18)F-FDG-PET and computerized tomography (CT) within the last 80 days were involved in this study. They were 18 women and 14 men, with age range 43-83 years. Maximum standardized uptake values (SUVmax) in primary and metastatic lesions for all patients were measured. The lesions were categorized into 4 different Groups according to their site. Partial volume corrections were applied using the CT sizes of lesions to obtain corrected SUVmax values. Average corrected SUVmax in each lesion site was calculated and compared between the 4 Groups. A total of 81 primary and metastatic lesions were included in this analysis. They were 28 mediastinal-hilar lymph node lesions, 26 lung lesions, 11 solid organ lesions, and 16 bone marrow lesions. The average uncorrected SUVmax for the primary lung lesions, mediastinal-hilar lymph node lesions, solid organ lesions, and the bone marrow lesions before application of partial volume correction formula were 7.2+/-3.2; 7.0+/-2.7; 6.3+/-3.4 and 7.0+/-3.4, respectively. The average corrected SUVmax for the lesions in the above mentioned regions were 11+/-6, 10+/-4, 13+/-7, and 18+/-13, respectively. A statistically significant difference was observed in the average SUVmax values between lung lesions and nodal lesions compared to the bone marrow lesions. In conclusion, our findings indicate that metabolic activities of lung cancer lesions vary depending on the sites of metastatic disease.


Assuntos
Carcinoma/diagnóstico por imagem , Carcinoma/secundário , Fluordesoxiglucose F18/farmacocinética , Aumento da Imagem/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Carcinoma/metabolismo , Simulação por Computador , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Ann Nucl Med ; 23(4): 341-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19367446

RESUMO

OBJECTIVES: Correction of the "partial volume effect" has been an area of great interest in the recent times in quantitative PET imaging and has been mainly studied with count recovery models based upon phantoms that incorporate hot spheres in a cold background. The goal of this research study was to establish a similar model that is closer to a biological imaging environment, namely hot spheres/lesions in a warm background and to apply this model in a small cohort of patients. METHODS: A NEMA phantom with six spheres (diameters 1-3.7 cm) was filled with (18)FDG to give sphere:background activity ratios of 8:1, 6:1, and 4:1 for three different acquisitions on a Philips Allegro scanner. The hot sphere SUVmax and the background average SUV were measured for calculation of recovery coefficients (RCs). Using the RCs, the lesion diameters, and the lesion:background ratio, the SUVmax of 64 lesions from 17 patients with biopsy proven lung cancer were corrected. RESULTS: The RCs versus sphere diameters produced characteristic logarithmic curves for each phantom (RCs ranged from 80% to 11%). From a cohort of 17 patients with biopsy proven lung cancer, 64 lesions combined had a mean SUVmax of 7.0 and size of 2.5 cm. After partial volume correction of the SUVmax of each lesion, the average SUVmax increased to 15.5. CONCLUSIONS: Hot spheres in a warm background more closely resemble the actual imaging situation in a living subject when compared to hot spheres in a cold background. This method could facilitate generation of equipment specific recovery coefficients for partial volume correction. The clinical implications for the increased accuracy in SUV determination are certainly of potential value in oncologic imaging.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Modelos Biológicos , Tomografia por Emissão de Pósitrons/métodos , Biópsia , Humanos , Processamento de Imagem Assistida por Computador , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Imagens de Fantasmas , Temperatura
19.
Breast Cancer Res Treat ; 116(3): 531-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19152027

RESUMO

Image-guided treatment planning that minimizes irradiation of critical lymph nodes (LNs) may reduce the incidence and severity of long term complications following breast cancer treatment. This localization cannot be obtained with conventional imaging techniques and we undertook this proof of concept study to determine whether a coordinated use of SPECT and CT has sufficient precision to inform radiation planning and potentially lessen the incidental exposure of critical LNs. Thirty-two consecutive women with breast cancer were injected in the arm ipsilateral to their breast cancers prior to radiation treatment with 0.5 mCi of filtered (99m)Tc-sulfur colloid and underwent scanning with a hybrid device which combined a dual-head SPECT camera and a low-dose, single slice CT scanner. The number of visualized LNs as well as their locations, maximum counts, and total uptake were recorded. Coordinates derived from the SPECT/CT fusion images were used to map LN locations onto the 3D radiation treatment planning system. A mean of 3.4 (SD 2.0) lymph nodes were detected in each subject. Level I and II LNs were detected more often in patients who had sentinel node biopsies, and more supraclavicular nodes were detected in patients who had undergone axillary dissection (P < 0.001). SPECT-CT derived LN coordinates were successfully mapped onto radiation simulation CT scans for all patients. SPECT/CT fusion images localize the LNs draining the arm after breast cancer surgery. These finding suggest that SPECT/CT may be helpful in minimizing incidental LN irradiation and in directing breast cancer therapy to reduce long-term morbidity.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Biópsia de Linfonodo Sentinela , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Braço/diagnóstico por imagem , Braço/patologia , Braço/cirurgia , Neoplasias da Mama/cirurgia , Diagnóstico por Imagem , Drenagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Linfonodos/cirurgia , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Projetos Piloto , Prognóstico , Compostos Radiofarmacêuticos , Coloide de Enxofre Marcado com Tecnécio Tc 99m
20.
Nucl Med Commun ; 29(6): 521-6, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18458598

RESUMO

BACKGROUND AND OBJECTIVES: Currently, there is no definite consensus regarding the best index to assess disease activity with fluorodeoxyglucose-PET imaging. Maximum standardized uptake value (SUVmax) is most frequently used in day-to-day practice for this purpose. This approach very often reflects the metabolic activity of only a small sample of the total ongoing process in the entire body. Here we introduce a new concept called metabolic burden (MB) to measure disease activity in cancer patients. MATERIALS AND METHODS: MB was calculated by measuring the volume (VCT) around a lesion that appeared on computed tomography (CT), the mean SUV that appeared on PET of the CT volume (SUVmean CT), and the recovery coefficient (RC) using the following formula: (Equation is included in full-text article.) If CT was unavailable, a region of interest (ROI) around the lesion was defined by a 40% SUVmax threshold and the volume and SUVmean were determined for that ROI. The whole-body metabolic burden (WBMB) was calculated as the sum of the individual MBs of all the lesions identified. We retrospectively reviewed 19 patients with non-Hodgkin's lymphoma who were treated with commercially available anti-CD20 radioimmunotherapy agents or conventional chemotherapy. All had a pretreatment and posttreatment fluorodeoxyglucose-PET and CT scan within 1-3 months of receiving systemic therapy. Either abnormal areas appearing on PET alone or corresponding lesions on CT were used to calculate the tumor volume (TV). Nodes of less than 2 cm occurring in clusters were grouped together into a single ROI. Thirty-eight regional collections in 14 patients were found in combined pretreatment and posttreatment studies and were assessed. The TVs varied in pretreatment size from 5.8 to 857 cm and posttreatment from 0 to 81 cm. Pretreatment WBMB varied from 27 to 10 218 cm and posttreatment from 0 to 279 cm. We then compared the standard indices of SUVmean and SUVmax with those of WBMB to determine which of the indices would have the best sensitivity as a predictor of therapeutic response. RESULTS: Five of the 19 patients had a complete response. In 14 patients with partial response, the average change in WBMB was 80%, the TV decreased by 76%, the SUVmax decreased by 42%, and the SUVmean decreased by 38.5%. CONCLUSION: The results of this analysis demonstrate that measurement of WBMB may prove to be superior to the existing methods in assessing and managing patients with non-Hodgkin's lymphoma. This index may be the best way to monitor the changes in WBMB as a patient is undergoing treatment.


Assuntos
Algoritmos , Fluordesoxiglucose F18/farmacocinética , Interpretação de Imagem Assistida por Computador/métodos , Linfoma/diagnóstico por imagem , Linfoma/metabolismo , Imagem Corporal Total/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Índice de Gravidade de Doença , Distribuição Tecidual
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