Chuan Miao Xie

Diffusion-weighted magnetic resonance imaging for prediction of response of advanced cervical cancer to chemoradiation.

Purpose: The aim of the study was to investigate diffusion-weighted imaging as an early predictor in detection of response to chemoradiation in advanced cervical cancer. Methods: Fourteen advanced cervical cancer patients treated with chemoradiation were enrolled in this study. All patients underwent conventional magnetic resonance imaging and diffusion-weighted imaging before the start of therapy, after 2 weeks of therapy, and at the completion of therapy. The tumor volumes and apparent diffusion coefficient (ADC) values of cervical lesions were measured at each examination. The correlation of ADC values and tumor regression was investigated. Results: The mean ADC value of cervical lesion significantly increased as early as 2 weeks after chemoradiation. The ADC values before therapy did not significantly correlate with tumor response. The ADC values after 2 weeks of therapy did not show a significant correlation with tumor response. The change in ADC values after 2 weeks of therapy correlated with tumor response. Conclusions: Diffusion-weighted imaging may provide an early surrogate biomarker for tumor response in advanced cervical cancers.

Abnormal baseline brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy revealed by resting-state functional MRI

Neurocognitive dysfunction of varying degrees is common in patients with hepatitis B virus-related cirrhosis (HBV-RC) without overt hepatic encephalopathy (OHE). However, the neurobiological mechanisms underlying these dysfunctions are not well understood. We sought to identify changes in the neural activity of patients with HBV-RC without OHE in the resting state by using the amplitude of low-frequency fluctuation (ALFF) method and to determine whether these changes were related to impaired cognition. Resting-state functional MRI data from 30 patients with HBV-RC and 30 healthy controls matched for age, sex, and years of education were compared to determine any differences in the ALFF between the two groups. Cognition was measured with the psychometric hepatic encephalopathy score (PHES), and the relationship between these scores and ALFF variation was assessed. Compared with controls, patients showed widespread lower standardized ALFF (mALFF) values in visual association areas (bilateral lingual gyrus, middle occipital gyrus, and left inferior temporal gyrus), motor-related areas (bilateral precentral gyrus, paracentral lobule, and right postcentral gyrus), and the default mode network (bilateral cuneus/precuneus and inferior parietal lobule). Higher mALFF values were found in the bilateral orbital gyrus/rectal gyrus. In patients, mALFF values were significantly positive correlated with the PHES in the right middle occipital gyrus and bilateral precentral gyrus. Our findings of resting-state abnormalities in patients with HBV-RC without OHE suggest that neurocognitive dysfunction in patients with HBV-RC without OHE may be caused by abnormal neural activity in multiple brain regions.

CT and MRI of radiation-induced sarcomas of the head and neck following radiotherapy for nasopharyngeal carcinoma

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.

Magnetic resonance imaging features of nasopharyngeal carcinoma and nasopharyngeal non-Hodgkin's lymphoma: Are there differences?

PURPOSE To describe differences in the primary tumour and distribution of cervical lymphadenopathy for cases of nasopharyngeal carcinoma (NPC) and nasopharyngeal non-Hodgkins lymphoma (NPNHL) using magnetic resonance (MR) imaging. MATERIALS AND METHODS MR images of patients with NPC (n = 272) and NPNHL (n = 118) were independently reviewed by two experienced radiologists. RESULTS NPC had a higher incidence of tumour invasion associated with the levator and tensor muscles of the velum palatine, the longus colli and medial pterygoid muscles, the base of the pterygoid process, the clivus, the base and greater wing of the sphenoid bone, the petrous apex, the foramen lacerum, the foramen ovale, the hypoglossal canal, and intracranial infiltration. In contrast, NPNHL had a higher incidence of tumour invasion associated with the hypopharynx, the palatine and lingual tonsils, as well as the ethmoid and maxillary sinuses. NPNHL also had a higher incidence of extensive and irregular bilateral lymphadenopathy, and lymphadenopathy in the parotid. CONCLUSIONS NPC more often involved an unsymmetrical tumour with a propensity to invade both widely and deeply into muscle tissue, the fat space, the neural foramen, and the skull base bone. In contrast, NPNHL tended to be a symmetrical and diffuse tumour with a propensity to spread laterally through the fat space and along the mucosa to the tonsils of the oropharynx and hypopharynx. These differences facilitate a differentiation of these diseases using MR images, and enhance our understanding of the biological behavior of these malignant tumours of the nasopharynx.

Kimura's disease: The CT and MRI characteristics in fifteen cases

OBJECTIVE To summarize the CT and MRI features in a series of fifteen cases of Kimuras disease. MATERIALS AND METHODS The clinical data, CT and MRI findings of 15 patients with histologically proved Kimuras disease were retrospectively reviewed. All imaging data were consensually evaluated by two radiologists to determine the lesion location, number, morphology, margin, signal intensity or CT density, lesion texture, contrast enhancement pattern and involvement of adjacent structures. RESULTS There were 14 male and 1 female, with peripheral blood eosinophilia in all 14 patients. 13 patients were presented with a painless mass. 13 patients had lesions located in the head and neck related to the major salivary glands. 1 patient had lesion in groin. Subcutaneous fat diffuse atrophy around the tumor site was found in 11 patients. 9 patients had solitary mass and 6 patients had multiple masses. Most masses were ill-defined, but no specific density or signal patterns were found. Most patients exhibited enlarged or obviously enhanced abnormal lymph nodes but without necrosis. CONCLUSION The characteristic distribution, morphology with enlarged draining lymphadenopathy, combined with the clinical features and laboratory examination enables a confident preoperative diagnosis of Kimuras disease.

An experimental study on acute brain radiation injury: Dynamic changes in proton magnetic resonance spectroscopy and the correlation with histopathology

PURPOSE To investigate the correlation between the alterations of single-voxel (1)H MRS and the histopathological characteristics of radiation brain injury following radiation. MATERIALS AND METHODS Twenty-seven rabbits were randomized into nine groups to receive radiation with a single dose of 25 Gy. The observation time points included a pre-radiation and 1, 2, 3, 4, 5, 6, 7, and 8 wk following radiation. Each treatment group underwent conventional MRI and single-voxel 1H MRS, N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) were observed over the region of interest, and the presence or absence of lactate (Lac) and lipid (Lip) was detected. Histological specimens of each group were obtained after image acquisition. RESULTS The values of Cho were significantly increased in the first 3 wk, and decreased over the following 5 wk after radiation. Levels of NAA showed a trend toward a decrease 5 wk after radiation. The levels of Cr were not changed between before and after radiation. The Cho/NAA metabolic ratio was significantly increased in weeks 6, 7, and 8 following irradiation, compared to pre-radiation values. Vascular and glial injury appeared on 2 wk after RT in the histology samples, until 4 wk after RT, necrosis of the oligodendrocytes, neuronal degeneration and demyelination could be observed. CONCLUSIONS MRS is sensitive to detect metabolic changes following radiation, and can be used in the early diagnosis of radiation brain injury.

Nasopharyngeal cancer: Impact of skull base invasion on patients prognosis and its potential implications on TNM staging

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.

Nasopharyngeal carcinoma patients with retropharyngeal lymph node metastases: A minimum axial diameter of 6 mm is a more accurate prognostic predictor than 5 mm

OBJECTIVE The criteria for the diagnosis of metastatic retropharyngeal lymph nodes (RLNs) have not yet been resolved and are not included in the current edition of the American Joint Committee on Cancer (AJCC) staging system (seventh edition) for the staging of nasopharyngeal carcinoma (NPC). The aim of this study was to use MRI to identify an RLN size criterion that can accurately predict prognosis in patients with NPC. MATERIALS AND METHODS Eight hundred seventeen patients with newly diagnosed localized NPC were identified. All of the patients underwent MRI before treatment with definitive radiation therapy. All the MRI studies and medical records were reviewed retrospectively. Overall survival (OS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS) were assessed using SPSS software (version 17.0). RESULTS RLN size cutoffs of ≥ 5 mm and of ≥ 6 mm were used. There was no significant difference in OS (p = 0.216), DMFS (p = 0.081), or LRFS (p = 0.067) in patients with RLNs ≥ 5 mm and in those with RLNs < 5 mm. When 6 mm was used as a size cutoff, significant differences in OS (p = 0.000) and DMFS (p = 0.001) were identified; there was no significant difference observed for LRFS (p = 0.380). CONCLUSION A minimum axial RLN diameter of 6 mm was a more accurate prognostic predictor in NPC patients with RLN metastases than 5 mm.

Computed tomographic findings of skull base bony changes after radiotherapy for nasopharyngeal carcinoma: Implications for local recurrence

OBJECTIVE To evaluate bony changes in the skull base after radiotherapy by computed tomography (CT) and their correlation with local recurrence in patients with nasopharyngeal carcinoma (NPC) without previous involvement of the skull base. DESIGN Retrospective study. SETTING Sun-Yat Sen University Cancer Center. METHODS The records of 80 patients with NPC during the period from January 1992 to December 2005 were reviewed. All patients had been treated with radical radiotherapy or chemoradiotherapy at standard doses and were followed up with plain and contrast-enhanced CT every 6 months for 45.5 (range 12-108) months. MAIN OUTCOME MEASURES The types, areas, time of the first occurrence after radiotherapy and development of the postradiation bony changes of the skull base, and local recurrence rates of NPC were measured. RESULTS Eighteen patients (22.5%) had sclerosis in some area of the skull base, and the sclerosis in 5 (27.8%) of these patients changed into osteoporosis in 1 to 5 years after its appearance. Seventeen patients (21.3%) had osteolysis. The local recurrence rate of patients with osteolysis was observed to be significantly higher than that of patients with sclerosis (p < .0001). CONCLUSIONS The appearance of osteolytic changes in the skull base during follow-up of patients with NPC who had normal skull base morphology before treatment was associated with tumour recurrence.

Proposal for a new risk classification system for nasopharyngeal carcinoma patients with post-radiation nasopharyngeal necrosis

PURPOSE To analyze the clinical outcomes of nasopharyngeal carcinoma (NPC) patients with post-radiation nasopharyngeal necrosis (PRNN) and construct a new risk classification system for predicting survival of PRNN. METHODS A total of 276 patients with PRNN were consecutively enrolled. Complete magnetic resonance (MR) images of the nasopharynx and neck were available for all patients and were used to assess nasopharyngeal necrosis status. After 2010, patients with PRNN were initially treated by radical endoscopic necrectomy followed by reconstruction with nasal flap (ENNF). RESULTS The 1-year and 2-year overall survival (OS) was 65.0% and 51.6%, respectively. Three variables affected survival: osteoradionecrosis, re-irradiation, and internal carotid artery (ICA) exposure, and only two variables were found to be independent prognostic factors: re-irradiation (hazard ratio [HR] 1.75, P=0.001) and internal carotid artery (ICA) exposure (hazard ratio [HR] 1.80, P=0.001). These two variables were combined to create a new risk classification system for PRNN. 131 (47.5%), 110 (39.9%), and 35 (12.7%) patients were classified into low-, intermediate- and high-risk group, with the 2-year OS rates of 64.8%, 45.1%, and 22.5%, respectively (P<0.001). ENNF was associated with a better OS in these three group patients compared with conservative management with statistical or marginal statistical significance (2-year OS low-risk group, 90.9% vs 61.1%, p=0.081; intermediate-risk group: 100% vs 37.8%, P=0.001; and high-risk group, 57.1% vs 20.8%, p=0.066). CONCLUSION The new risk classification system provides accurate estimates of prognosis. ENNF surgery may lead to better survival outcome than conservative management in PRNN patients.