Publications (40) View all
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Article: CT and MRI of radiation-induced sarcomas of the head and neck following radiotherapy for nasopharyngeal carcinoma.
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ABSTRACT: AIM: To investigate the radiological findings of head and neck radiation-induced sarcomas (RISs) following radiotherapy for nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Fifty-nine patients with RISs were identified. Imaging characteristics on computed tomography (CT) and magnetic resonance imaging (MRI), including lesion location, extent, size, margin, internal architecture, pattern, and degree of enhancement, together with patient characteristics at NPC diagnosis and latency periods, were reviewed. RESULTS: The study included 20 women and 39 men, with a median age of 49 years (range 30-71 years). The median latency was 9 years (range 3-37 years). The median radiation dose at the site of RIS was 66 Gy (range 44-78 Gy). The most common histological RIS types were fibrosarcoma (44.1%) and osteosarcoma (30.5%). The most common RIS sites were the paranasal sinuses and the nasal cavity (39%), the neck (16.9%), and the mandible (15.3%). The mean size was 5.1 cm (range 1.2-8.6 cm). Overall, 78% of lesions extended to adjacent spaces and 66.1% were accompanied by bone destruction. Heterogeneous density/signal intensity before and after enhancement was seen in all lesions on imaging. Marked lesion enhancement was noted in 49 cases (76.3%). CONCLUSIONS: The radiologist should be aware of the different sites at which RISs occur and the radiological appearance of the wide variety of RIS subtypes. Careful imaging follow-up is necessary for early detection of RISs in patients with NPC after radiotherapy.Clinical radiology 03/2013; · 1.65 Impact Factor -
Article: MRI signal changes in the skull base bone after endoscopic nasopharyngectomy for recurrent NPC: A serial study of 9 patients.
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ABSTRACT: PURPOSE: This study was focused on the serial changes in magnetic resonance images (MRI) of the skull-base bone that occur after endoscopic nasopharyngectomy in patients with local recurrent nasopharyngeal carcinoma (rNPC). MATERIALS AND METHODS: Nine patients with histologically proven rNPC were enrolled in this study. Two experienced radiologists independently reviewed all presurgical and postsurgical MR images for each patient. RESULTS: At 36 sites on the skull base, the MRI signal underwent a change after surgery, which took the form of a heterogeneous pattern of hypointense regions with moderate contrast enhancement on T1WI. The onset of changes ranged between 2 weeks and 3 months after surgery. For 21 of the sites, the changes subsided over the course of follow-up, while in 6 they remained stable. At 9 sites, the alteration MRI signal became more pronounced with time. Changes were more common on the homolateral side of the skull base with respect to the recurrent tumor (P<0.05). The skull-base bone adjacent to the resection boundary had a higher incidence of signal change than nonadjacent areas (P<0.05). CONCLUSIONS: MRI changes in the skull base bone, having a number of distinguishing characteristics, appear to be a common sequel to endoscopic nasopharyngectomy for rNPC.European journal of radiology 11/2012; · 2.65 Impact Factor -
Article: Nasopharyngeal cancer: Impact of skull base invasion on patients prognosis and its potential implications on TNM staging.
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ABSTRACT: PURPOSE: To evaluate patterns of skull base invasion and its possible impact on tumor (T)-staging in nasopharyngeal carcinoma (NPC) using magnetic resonance imaging (MRI). MATERIALS AND METHODS: 838 consecutive newly diagnosed by biopsy proven and untreated patients with NPC underwent MRI. The skull-base invasion of NPC was classified according to their incidence from proximal sites to more distant sites surrounding the nasopharynx as: high (≥35%), medium (≥5-35%), and low (<5%) groups. A retrospective analysis of data consisting of a 5-year follow-up was carried out. The skull base invasion was related to their tumor (T) staging and prognosis at the 5-year follow-up after treatment with definitive radiation therapy. In addition, a survival health-related quality of life (QOL), overall survival (OS), local relapse-free survival (LRFS) and distant metastasis-free survival (DMFS) were also assessed among the three groups. RESULTS: The total incidence of skull-base invasion was 65.51% (549/838). The differences in T-stage distribution, and the total survival health-related QOL, among the three groups were statistically significant (χ(2)=160.45, p<0.005; χ(2)=38.43, p<0.005, respectively). The differences between any two of the three groups were also significant, except when the medium grade was compared to the low grade. Significant differences were observed with regard to 5-year OS (83.2%, 74.7%, 59.2%, p=0.000) and DMFS (95.0%, 88.0%, 88.0%, p=0.016); no significant difference was observed in LRFS (95.3%, 95.6%, 91.23%, p=0.450). CONCLUSIONS: The results indicate that medium and low group displayed similar findings of skull base invasion, and survival status. We, therefore, propose that patients in these two groups be grouped under T4 in the TNM classification that might have a bearing in implementing optimum treatment.European journal of radiology 11/2012; · 2.65 Impact Factor -
Article: Computed tomography characterization of neuroendocrine tumors of the thymus can aid identification and treatment.
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ABSTRACT: Background Neuroendocrine tumors of the thymus are extremely rare anterior mediastinal tumors. The few studies reporting these tumors have focused on the clinical manifestations and do not provide a summary of characteristic computed tomography (CT) findings.PurposeTo investigate the CT appearances of neuroendocrine tumors of the thymus in order to improve the diagnostic and resection efficacy.Material and Methods Nine cases of pathologically identified thymic neuroendocrine tumors were retrospectively analyzed by CT. All the patients underwent non-enhanced and contrast-enhanced CT. Multiple CT features were examined, including tumor location, shape, margins, CT attenuation, involvement of surrounding structures, and distant metastasis.ResultsA total of nine masses were examined in this study. The maximum tumor diameter ranged from 5 to 14 cm (average, 9 cm). The shapes of six masses were lobulated and three were rounded or oval and the margins of seven masses were unclear while two masses were sharp. All the masses showed hypodensity or isodensity compared to muscles in the anterior thoracic wall on non-enhanced CT images. Two masses showed homogeneous attenuation by non-enhanced CT imaging and moderate homogeneous enhancement after contrast administration, while seven masses showed heterogeneous attenuation with patchy low-attenuation foci and showed moderate to strong heterogeneous enhancement. Involvement of adjacent structures was observed in six cases. Five cases were observed to have lymph node metastases and four cases had distant metastases.Conclusion Neuroendocrine tumors of the thymus are rare tumors of the anterior mediastinum with a number of distinct CT characteristics. Most importantly, the density of the tumors was heterogeneous with necrosis or cystic degeneration and moderately or strongly enhancement after bolus injection of contrast medium, which may allow for more efficient tumor identification. Thus, CT can improve of the diagnosis of neuroendocrine tumors and provide critical information for surgical planning.Acta Radiologica 10/2012; · 1.37 Impact Factor -
Article: Primary nasopharyngeal non-Hodgkin's lymphoma: imaging patterns on MR imaging.
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ABSTRACT: OBJECTIVES: To summarize the distinct imaging features of different subtypes of primary nasopharyngeal non-Hodgkin's lymphomas (NHLs). MATERIALS AND METHODS: Clinical data and magnetic resonance imaging findings of 71 patients with histologically proven primary nasopharyngeal NHLs were retrospectively reviewed. The tumor distribution, signal intensity, lesion texture, contrast enhancement properties, extra-chamber involvement, regional structure invasion, and cervical lymphadenopathy were evaluated and compared between different subtypes of NHLs. RESULTS: Of the patients, 70.4% had B-cell lymphomas; 64.8% had symmetrical and diffuse involvement of nasopharynx walls; and 19.7% had superficial ulcerations. Extra-chamber involvement and regional structure invasion occurred in most patients. The frequency of neck node involvement was up to 83.10%; 62.7% of them were bilateral involvement. Patients with T-cell or nature killer/T-cell NHLs had a higher incidence of superficial ulcerations, nasal cavity, and paranasal sinus invasion than B-cell NHLs (P<.05). Patients with B-cell NHLs had a higher incidence of cervical lymphadenopathy specifically in Level VA and parotid region than T-cell or nature killer/T-cell (NK/T-cell) NHLs (P<.05). CONCLUSION: Primary nasopharyngeal NHLs had some characteristic imaging features and different subtypes of nasopharyngeal NHLs had some distinct imaging features.Clinical imaging 10/2012; · 0.73 Impact Factor
