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1.
Radiat Oncol ; 10: 81, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25888772

RESUMO

BACKGROUND: High-dose-rate (HDR) brachytherapy using the mold technique is a less invasive treatment for early lip and oral cavity cancer. However, limited reports exist regarding the feasibility of this method. In this retrospective study, we evaluated the outcome of this therapy and investigated its feasibility for lip and oral cavity tumors. METHODS: Between May 2002 and December 2010, 17 patients (median age, 80.0 years) with histologically confirmed squamous cell carcinoma of the lip or oral cavity were treated by means of HDR brachytherapy using the mold technique after external beam radiotherapy (EBRT). Tumor sites included the buccal mucosa in eight cases, the gingiva in three cases, the lips in two cases, the floor of the mouth in two cases, and the hard palate in two cases. For all patients, EBRT (30 Gy/15 fractions), was performed before HDR brachytherapy. Two 6-Gy fractions were delivered twice daily for 2 days a week with an interval of 6 hours between the fractions. The total HDR brachytherapy dose was 24 Gy. Prior to EBRT, two patients with neck metastasis underwent neck dissection, and one patient with an exophytic tumor underwent tumor resection. RESULTS: The median follow-up period was 53.4 (range, 4.8-83.4) months. Of the 17 patients, 14 (82.4%) achieved a complete response, and three (17.6%) displayed a partial response. The overall 3- and 5-year survival rates were both 68.8%, the 3- and 5-year disease-specific survival rates were both 86.7%, and the 3- and 5-year local control rates were both 54.1%. Seven patients developed local recurrence at a median time of 3.4 (range, 1.7-29.1) months after treatment. Nodal and lung metastases occurred separately in two patients. By the end of the follow-up period, two patients had died of the primary disease and four patients had died of other causes. CONCLUSIONS: Although there is a need to improve the technical aspects of the treatment protocol, HDR brachytherapy using the mold technique might be a therapeutic option for superficial lip or oral cavity tumors, especially in older patients who have a poor performance status or are in poor physical condition.


Assuntos
Braquiterapia/instrumentação , Carcinoma de Células Escamosas/radioterapia , Neoplasias Labiais/radioterapia , Modelos Anatômicos , Neoplasias Bucais/radioterapia , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/efeitos adversos , Braquiterapia/métodos , Carcinoma de Células Escamosas/secundário , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/secundário , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Mucosite/etiologia , Esvaziamento Cervical , Recidiva Local de Neoplasia/epidemiologia , Radiodermite/etiologia , Dosagem Radioterapêutica , Erros de Configuração em Radioterapia/prevenção & controle , Radioterapia de Alta Energia/efeitos adversos , Estudos Retrospectivos
2.
Oncol Lett ; 8(2): 819-824, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25013504

RESUMO

The aim of this study was to create a new phantom for a 3 Tesla (3T) magnetic resonance imaging (MRI) device for the calculation of the apparent diffusion coefficient (ADC) using diffusion-weighted imaging (DWI), and to mimic the ADC values of normal and tumor tissues at various temperatures, including the physiological body temperature of 37°C. The phantom was produced using several concentrations of sucrose from 0 to 1.2 M, and the DWI was performed using various phantom temperatures. The accurate ADC values were calculated using the DWIs of the phantoms, and an empirical formula was developed to calculate the ADC values of the phantoms from an arbitrary sucrose concentration and arbitrary phantom temperature. The empirical formula was able to produce ADC values ranging between 0.33 and 3.02×10-3 mm2/sec, which covered the range of ADC values of the human body that have been measured clinically by 3T MRI in previous studies. The phantom and empirical formula developed in this study may be available to mimic the ADC values of the clinical human lesion by 3T MRI.

3.
Acta Med Okayama ; 67(6): 359-67, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24356720

RESUMO

It is well known that many tumor tissues show lower apparent diffusion coefficient (ADC) values, and that several factors are involved in the reduction of ADC values. The aim of this study was to clarify how much each factor contributes to decreases in ADC values. We investigate the roles of cell density, extracellular space, intracellular factors, apoptosis and necrosis in ADC values using bio-phantoms. The ADC values of bio-phantoms, in which Jurkat cells were encapsulated by gellan gum, were measured by a 1.5-Tesla magnetic resonance imaging device with constant diffusion time of 30sec. Heating at 42℃ was used to induce apoptosis while heating at 48℃ was used to induce necrosis. Cell death after heating was evaluated by flow cytometric analysis and electron microscopy. The ADC values of bio-phantoms including non-heated cells decreased linearly with increases in cell density, and showed a steep decline when the distance between cells became less than 3µm. The analysis of ADC values of cells after destruction of cellular structures by sonication suggested that approximately two-thirds of the ADC values of cells originate from their cellular structures. The ADC values of bio-phantoms including necrotic cells increased while those including apoptotic cells decreased. This study quantitatively clarified the role of the cellular factors and the extracellular space in determining the ADC values produced by tumor cells. The intermediate diffusion time of 30msec might be optimal to distinguish between apoptosis and necrosis.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Difusão , Células Jurkat/metabolismo , Imagens de Fantasmas , Transporte Biológico/fisiologia , Contagem de Células , Células Cultivadas , Espaço Extracelular/fisiologia , Citometria de Fluxo , Humanos , Técnicas In Vitro , Células Jurkat/patologia , Fatores de Tempo
4.
Pediatr Dent ; 35(1): 67-70, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23635902

RESUMO

PURPOSE: The purpose of this study was to evaluate the radiological and histopathological findings of 11 patients with unerupted first molars to verify the factors obstructing spontaneous eruption. METHODS: The patients' clinical, radiological, and histopathological data were evaluated retrospectively to determine histopathological diagnosis, radiographic findings, methods of surgical management, and postoperative course. RESULTS: This study involved 4 male and 7 female patients (mean age=9.5 years old). Nine cases involved the mandible. The patients' histopathological diagnoses included 3 odontogenic tumors, 2 odontogenic cysts, and 6 hyperplastic dental follicles. Radiographically, 10 cases showed characterless enlargement of the follicular space, while only 1 displayed radiopaque bodies. One patient with a tumor underwent enucleation, and 1 with a cyst underwent cystectomy and tooth extraction. The others underwent wide excision or partial excision of the surrounding tissue at the top of the impacted tooth. Tumor relapse was observed in 3 cases. CONCLUSION: Surgeons should perform aggressive treatment for patients with unerupted teeth because spontaneous eruption is rare in cases involving non-neoplastic lesions such as hyperplastic dental follicles.


Assuntos
Dente Molar/diagnóstico por imagem , Dente Impactado/etiologia , Dente não Erupcionado/etiologia , Adolescente , Criança , Saco Dentário/patologia , Cisto Dentígero/complicações , Cisto Dentígero/cirurgia , Feminino , Seguimentos , Humanos , Hiperplasia , Masculino , Doenças Mandibulares/complicações , Doenças Mandibulares/cirurgia , Neoplasias Mandibulares/complicações , Neoplasias Mandibulares/cirurgia , Doenças Maxilares/complicações , Doenças Maxilares/cirurgia , Neoplasias Maxilares/complicações , Neoplasias Maxilares/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Dente Molar/patologia , Dente Molar/cirurgia , Recidiva Local de Neoplasia/patologia , Tumores Odontogênicos/complicações , Tumores Odontogênicos/cirurgia , Radiografia , Estudos Retrospectivos , Extração Dentária/métodos , Dente Impactado/diagnóstico por imagem , Dente Impactado/cirurgia , Dente não Erupcionado/diagnóstico por imagem , Dente não Erupcionado/cirurgia
6.
Artigo em Inglês | MEDLINE | ID: mdl-22986252

RESUMO

Ossifying fibroma (OF), a rare nonodontogenic tumor, is defined as a bone-related jawbone lesion. The main histopathological feature of OF is the replacement of bone by benign connective tissue. Ossifying fibroma usually occurs in the second to fourth decades of life and shows a predilection for females. Ossifying fibroma most commonly occurs in the mandible, and OF arising from the anterior part of the maxilla is rare. Ossifying fibromas display various radiographic findings, including varying degrees of radiolucency and radiopacity, depending on the proportions of their soft and hard tissue components. Depending on their components, it can be difficult to distinguish OF from other fibroosseous lesions and some odontogenic tumors by using conventional radiographs, computed tomography, and magnetic resonance imaging (MRI). We report a case of OF in the anterior maxilla in a 56-year-old man, together with its histopathological and imaging findings including the dynamic MRI findings.


Assuntos
Fibroma Ossificante/diagnóstico , Imageamento por Ressonância Magnética/métodos , Neoplasias Maxilares/diagnóstico , Meios de Contraste , Diagnóstico Diferencial , Fibroma Ossificante/diagnóstico por imagem , Humanos , Masculino , Neoplasias Maxilares/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia Panorâmica , Tomografia Computadorizada por Raios X
7.
Artigo em Inglês | MEDLINE | ID: mdl-22981095

RESUMO

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor arising from odontogenic epithelial remnants within the jawbones. PIOSCC is histopathologically divided into 3 types: solid-type carcinoma, carcinoma derived from a keratocystic odontogenic tumor, and carcinoma derived from an odontogenic cyst. In this article, we report a case of solid-type PIOSCC involving reactive bone formation in the mandible in a 60-year-old female patient together with its histopathological and imaging findings.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Neoplasias Mandibulares/diagnóstico , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Mandibulares/patologia , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
8.
Artigo em Inglês | MEDLINE | ID: mdl-22668718

RESUMO

Odontogenic fibroma (OF) is a rare nonepithelial benign tumor arising from the odontogenic mesenchymal tissue in the jawbone. OFs are topographically categorized into 2 types, the central type and peripheral type, and are histopathologically divided into the epithelium-poor type and epithelium-rich type. The radiological findings of central OF commonly include a uni- or multilocular radiolucent area with a well-defined margin, which are similar to those of cysts and other benign tumors of the jawbone. Therefore, it is difficult to distinguish OF from these jawbone lesions on radiographs because of their noncharacteristic radiological findings. In this article, we report the cases of 2 patients with central OF who underwent magnetic resonance (MR) examinations and describe the usefulness of dynamic contrast-enhanced MR imaging for diagnosing OF.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias Mandibulares/patologia , Neoplasias Maxilares/patologia , Tumores Odontogênicos/patologia , Criança , Meios de Contraste , Feminino , Fibroma/patologia , Humanos , Estudos Retrospectivos , Adulto Jovem
9.
Artigo em Inglês | MEDLINE | ID: mdl-22669071

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI), especially dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), in extranodal non-Hodgkin lymphoma (NHL) of oral and maxillofacial regions. STUDY DESIGN: Thirteen cases with extranodal NHL were examined using MRI. T1-weighted images (T1WI) and T2-weighted images (T2WI) or short TI inversion recovery (STIR) images were obtained in all cases. Contrast-enhanced images and DCE-MRI were acquired in 10 and 7 cases, respectively. On DCE-MRIs, we analyzed the parameters as follows: contrast index at maximal contrast enhancement (CImax), maximum contrast index (CI) gain/CImax ratio, and washout ratios (WR(300), WR(600), and WR(900)) at 300, 600, and 900 seconds after contrast medium injection. RESULTS: The signal intensity of all lesions was hypointense to isointense on T1WIs and showed variable contrast enhancement patterns. On T2WIs and STIR images, the signal intensity was isointense to hyperintense in almost all cases. Analysis of DCE-MRI parameters in extranodal NHLs resulted in the identification of 4 types of CI curves according to CImax and WR: (1) CImax greater than 2.0 and WR(900) greater than 40%, (2) CImax greater than 2.0 and WR(900) less than 40%, (3) CImax less than 1.5 and WR(900) greater than 40%, and (4) CImax less than 1.5 and WR(900) greater than 40%. CONCLUSIONS: The signal intensities on MRI were not specific to extranodal NHL and resembled those of other tumor types. When CImax was less than 1.5 or WR900 was less than 40%, these parameters contributed to diagnosis in extranodal NHLs.


Assuntos
Neoplasias Maxilomandibulares/patologia , Linfoma não Hodgkin/patologia , Imageamento por Ressonância Magnética/métodos , Neoplasias Bucais/patologia , Adulto , Idoso , Carcinoma de Células Escamosas/diagnóstico , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Neoplasias do Seio Maxilar/patologia , Pessoa de Meia-Idade , Neoplasias Palatinas/patologia , Estudos Retrospectivos
10.
Artigo em Inglês | MEDLINE | ID: mdl-22677692

RESUMO

OBJECTIVE: High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites. STUDY DESIGN: Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy. RESULTS: At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence. CONCLUSIONS: Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors.


Assuntos
Braquiterapia/instrumentação , Braquiterapia/métodos , Carcinoma de Células Escamosas/radioterapia , Neoplasias Bucais/radioterapia , Idoso , Idoso de 80 Anos ou mais , Bochecha , Feminino , Humanos , Neoplasias Labiais/radioterapia , Masculino , Dosagem Radioterapêutica
11.
Eur J Radiol ; 81(11): 3306-12, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22578835

RESUMO

OBJECTIVES: To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) for differentiating between benign and malignant tumors in the palate. MATERIALS AND METHODS: 26 patients with submucosal palatal tumors were preoperatively examined using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), and washout ratios (WR300 and WR600) were determined from contrast index curves. The submucosal palatal tumors were divided into two groups according to their Tmax values: the early enhancement group (Tmax<300 s) consisted of 9 malignant tumors and 6 benign tumors, while the late enhancement group (Tmax≥300 s) included one malignant tumor and 10 benign tumors. We compared the following DCE-MRI parameters between the benign and malignant tumors: CImax and Tmax in all cases and CImax, Tmax, and the washout ratios in the early enhancement group. In addition, we performed a regression analysis of the relationships between tumor size and DCE-MRI parameters; i.e., CImax, Tmax, and washout ratios, among the malignant salivary gland tumors and pleomorphic adenomas. RESULTS: In all cases and the early enhancement group, significant differences in Tmax were detected between the benign and malignant tumors (P<0.001 and P<0.05, respectively), and the optimal Tmax cutoff value for differentiating between them was found to be 165 s. None of the other parameters displayed significant differences between the benign and malignant tumors. Only the WR600 of the pleomorphic adenomas was significantly correlated with tumor size (R2=0.92, P<0.001). CONCLUSIONS: Tmax is a useful parameter for distinguishing between benign and malignant submucosal palatal tumors.


Assuntos
Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Mucosa Bucal/patologia , Neoplasias Palatinas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
12.
Eur J Radiol ; 81(10): 2684-91, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22138118

RESUMO

OBJECTIVE: To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for minor salivary gland tumors in the oral cavity. MATERIALS AND METHODS: Thirty-two patients with minor salivary gland tumors were examined preoperatively using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), Tpeak; i.e., the time that corresponded to the CImax×0.90, and washout ratios (WR300 and WR600) were determined from contrast index (CI) curves. We compared these parameters between benign and malignant tumors and among the different histopathological types of minor salivary gland tumors. Then, we categorized the patients' CI curves into four patterns (gradual increase, rapid increase with high washout ratio, rapid increase with low washout, and flat). RESULTS: Statistically significant differences in Tmax (P=0.004) and Tpeak (P=0.002) were observed between the benign and malignant tumors. Regarding each histopathological tumor type, significant differences in Tmax (P<0.001), Tpeak (P<0.001), and WR600 (P=0.026) were observed between the pleomorphic adenomas and mucoepidermoid carcinomas. It was difficult to distinguish between benign and malignant tumors using our CI curve classification because that two-thirds of the cases were classified into the same type (gradual increase). CONCLUSION: The DCE-MRI parameters of minor salivary gland tumors contributed little to their differential diagnosis compared with those for major salivary gland tumors. During the diagnosis of minor salivary gland tumors, Tmax is useful for distinguishing between benign and malignant tumors.


Assuntos
Imageamento por Ressonância Magnética/métodos , Boca/patologia , Neoplasias das Glândulas Salivares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Artigo em Inglês | MEDLINE | ID: mdl-21778083

RESUMO

Malignant lymphoma is the second-most common malignancy in the head and neck region. Waldeyer's ring is the most common site of extranodal Hodgkin's lymphoma (NHL) in that region, and a small percentage of primary extranodal NHL occurs in the oral cavity. The most common sites of extranodal NHL in the oral region are the palate and maxilla, and nearly half of extranodal NHL cases arise from bone. It is difficult to diagnose extranodal NHL because of the variety of its radiological features. We report a case of primary extranodal NHL of the maxilla in a 68-year-old female patient with atypical imaging findings, along with the results of analysis of dynamic magnetic resonance imaging (MRI).


Assuntos
Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Linfoma não Hodgkin/patologia , Imageamento por Ressonância Magnética/métodos , Neoplasias Maxilares/patologia , Idoso , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Linfoma não Hodgkin/diagnóstico por imagem , Neoplasias Maxilares/diagnóstico por imagem , Mixoma/diagnóstico por imagem , Mixoma/patologia , Tumores Odontogênicos/diagnóstico por imagem , Tumores Odontogênicos/patologia , Radiografia , Neoplasias das Glândulas Salivares/diagnóstico por imagem , Neoplasias das Glândulas Salivares/patologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-21458329

RESUMO

Ameloblastic carcinoma is a rare malignant odontogenic carcinoma that has metastatic potential, and because of its rare incidence, there are few reports focusing on its radiologic imaging. If it shows aggressive appearances, it can be diagnosed as malignant tumor. But in case of negative appearance, it is difficult to distinguish ameloblastic carcinoma from ameloblastoma. We report a case of ameloblastic carcinoma of the maxilla in a 76-year-old female patient with radiologic images and pathologic features.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias Maxilares/diagnóstico , Tumores Odontogênicos/diagnóstico , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Ameloblastoma/diagnóstico , Biópsia , Meios de Contraste , Diagnóstico Diferencial , Feminino , Fluordesoxiglucose F18 , Seguimentos , Humanos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Intensificação de Imagem Radiográfica/métodos , Radiografia Panorâmica , Compostos Radiofarmacêuticos
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