Tumor Volume Is Better Than Diameter for Predicting the Prognosis of Patients with Early-Stage Non-small Cell Lung Cancer.

BACKGROUND: This study aimed to investigate whether tumor volume (TV) is better than diameter for predicting the prognosis of patients with early-stage non-small cell lung cancer (NSCLC) after complete resection. METHODS: This study retrospectively reviewed the clinicopathologic characteristics of 274 patients with early-stage NSCLC who had received pretreatment computed tomography (CT) scans and complete resection. TV was semi-automatically measured from CT scans using an imaging software program. The optimal cutoff of TV was determined by X-tile software. Disease-free survival (DFS) and overall survival (OS) were assessed by the Kaplan-Meier method. The prognostic significance of TV and other variables was assessed by Cox proportional hazards regression analysis. RESULTS: Using 3.046 cm3 and 8.078 cm3 as optimal cutoff values of TV, the patients were separated into three groups. A larger TV was significantly associated with poor DFS and OS in the multivariable analysis. Kaplan-Meier curves of DFS and OS showed significant differences on the basis of TV among patients with stage 1a disease, greatest tumor diameter (GTD) of 2 cm or smaller, and GTD of 2-3 cm, respectively. Using two TV cutoff points, three categories of TV were created. In 54 cases (19.7%), patients migrated from the GTD categories of 2 cm or smaller, 2-3 cm, and larger than 3 cm into the TV categories of 3.046 cm3 or smaller, 3.046-8.078 cm3, and larger than 8.078 cm3. CONCLUSION: TV is an independent prognostic factor of DFS and OS for early-stage NSCLC. The findings show that TV is better than GTD for predicting the prognosis of patients with early-stage NSCLC.

Nasopharyngeal carcinoma with paranasal sinus invasion: the prognostic significance and the evidence-based study basis of its T-staging category according to the AJCC staging system.

BACKGROUND: To evaluate the prognostic significance of paranasal sinus invasion for patients with NPC and to provide empirical proofs for the T-staging category of paranasal sinus invasion according to the AJCC staging system for nasopharyngeal carcinoma. METHODS: The clinical records and imaging studies of 770 consecutive patients with newly diagnosed, untreated, and nondisseminated NPC were reviewed retrospectively. The overall survival, distant metastasis-free survival, and local relapse-free survival of these patients were analyzed using the Kaplan-Meier method, and the differences were compared using the log-rank test. RESULTS: The incidence of paranasal sinus invasion was 23.6%, with the rate of incidence of sphenoid sinus invasion being the highest. By multivariate analysis, paranasal sinus invasion was shown to be an independent prognostic factor for overall survival, distant metastasis-free survival, and local relapse-free survival (p < 0.05 for all). No significant differences in overall survival, distant metastasis-free survival, and local relapse-free survival were observed between patients with sphenoid sinus invasion alone and those with maxillary sinus and ethmoid sinus invasion (p = 0.87, p = 0.80, and p = 0.37, respectively). The overall survival, distant metastasis-free survival, and local relapse-free survival for patients with stage T3 disease with paranasal sinus invasion were similar to the survival rates for patients with stage T3 disease without paranasal sinus invasion (p = 0.22, p = 0.15, and p = 0.93, respectively). However, the rates of overall survival and local relapse-free survival were better for patients with stage T3 disease with paranasal sinus invasion than for patients with stage T4 disease (p < 0.01, and p = 0.03, respectively). CONCLUSIONS: Paranasal sinus invasion is an independent negative prognostic factor for NPC, regardless of which sinus is involved. Our results confirm that it is scientific and reasonable for the AJCC staging system for nasopharyngeal carcinoma to define paranasal sinus invasion as stage T3 disease.

[MRI analysis of paranasal sinus invasion in 182 patients with nasopharyngeal carcinoma].

OBJECTIVE: The aim of the study was to analyze the nuclear magnetic resonance image (MRI) findings for invasion of paranasal sinuses in patients with nasopharyngeal carcinoma (NPC) and to improve the understanding of its MRI diagnosis. METHODS: The MRI data of 182 patients with nasopharyngeal carcinoma and paranasal sinus invasion were retrospectively analyzed. RESULTS: One hundred and eighty-two patients developed paranasal sinus invasion, of which, the incidence of sphenoid sinus invasion was highest. The MRI findings of paranasal sinus invasion of patients with NPC were as follows: 100%, 95.6% and 56.6% patients revealed damage of sinus wall, uneven thickening of mucosa, masses of the sinus cavity connected with the primary tumor of nasopharynx, and all the lesions presented iso- or slightly hypo-intense signal on T1WI and iso- or slightly hyper-intense signal on T2WI and significantly heterogeneous enhancement after contrast administration, which were consistent with the primary tumor of the nasopharynx regarding to the signal intensity and reinforcement schedule. 77.5% patients presented massive sinus cavity effusion. T2-weighted images are excellent in differentiating high signal intensity thickened mucosa or retained secretions from relatively lower signal intensity tumor. In contrast-enhanced MRI, tumor with solid enhancement can be differentiated from thickened mucosa related to inflammation with a thin superficial enhancement. 96.5% and 94.7% patients with maxillary sinus invasion and ethmoid sinus invasion were detected with the contrast enhanced axial T1-weighted MR imaging respectively, which were higher than those with the non-enhanced axial T1 and T2 imaging (88.4% and 77.9% for maxillary sinus invasion; 65.8% and 73.7% for ethmoid sinus invasion), the differences were statistically significant (P < 0.05 for all comparison). All patients with sphenoid sinus invasion were detected with the contrast enhanced sagittal T1-weighted MR imaging. CONCLUSION: Multiplanner MR scan and enhanced scan can improve the diagnosis of invasion of paranasal sinuses in patients with NPC. The MRI findings of patients with NPC with paranasal sinus invasion include sinus wall damage; unevenly thickening mucous membrane of sinuses; tumors in sinus cavity connective with the primary tumor of nasopharynx , or with massive sinus cavity effusion. The T2-weighted sequence and contrast enhanced sequence are conducive to differential diagnosis of inflammatory changes from neoplastic tissues. The enhanced axial T1-weighted section and the enhanced sagittal T1-weighted section are most helpful to detection of maxillary sinus, ethmoid sinus invasion and sphenoid sinus invasion, respectively.

Nasopharyngeal adenoid cystic carcinoma: magnetic resonance imaging features in ten cases.

Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with high local invasiveness. To date, there is no consensus on the imaging characteristics of NACC. To address this, we retrospectively reviewed 10 cases of NACC and summarized the magnetic resonance imaging (MRI) features. MR images of 10 patients with histologically validated NACC were reviewed by two experienced radiologists. The location, shape, margin, signal intensity, lesion texture, contrast enhancement patterns, local invasion, and cervical lymphadenopathy of all tumors were evaluated. Clinical and pathologic records were also reviewed. No patients were positive for antibodies against Epstein-Barr virus (EBV). The imaging patterns of primary tumors were classified into two types as determined by location, shape, and margin. Of all patients, 7 had tumors with a type 1 imaging pattern and 3 had tumors with a type 2 imaging pattern. The 4 tubular NACCs were all homogeneous tumors, whereas 3 (60%) of 5 cribriform NACCs and the sole solid NACC were heterogeneous tumors with separations or central necrosis on MR images. Five patients had perineural infiltration and intracranial involvement, and only 2 had cervical lymphadenopathy. Based on these results, we conclude that NACC is a local, aggressive neoplasm that is often negative for EBV infection and associated with a low incidence of cervical lymphadenopathy. Furthermore, MRI features of NACC vary in locations and histological subtypes.

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.

Prognostic Value of Regression Rate of Plasma EBV DNA After Induction Chemotherapy for Stage II-IVA Nasopharyngeal Carcinoma.

BACKGROUND/OBJECTIVE: We aimed to explore the prognostic value of regression rate (RR) of plasma Epstein-Barr virus (EBV) DNA after induction chemotherapy (IC) in patients with stages II-IVA nasopharyngeal carcinoma (NPC). METHODS: Eligible patients receiving IC followed by concurrent chemoradiotherapy were included. The cut-off value of pre-treatment EBV DNA (pre-IC DNA) and RR were identified by receiver operating curve (ROC). Recursive partitioning analysis (RPA) was applied to create new staging. Harrell's c-index and time-independent ROC were employed to compare different RPA staging. RESULTS: In total, 1,184 patients were included. The cut-off values of pre-IC DNA and RR were 16,200 copies/ml and 95.127% for patients receiving two cycles, and 5,520 copies/ml and 99.994% for those receiving three cycles. Notably, we only focused on patients receiving two cycles of IC. Patients with a RR >95.127% had significantly better 5-year overall survival (OS) than those with a RR ≤95.127% (86.2% vs. 54.3%, P <0.001). Then, RPA1 (pre-IC DNA + TNM staging + RR) and RPA2 (pre-IC DNA + TNM staging + post-IC EBV DNA [post-IC DNA]) staging systems were created. RPA1 staging achieved stronger power in OS prediction than RPA2 staging and TNM staging (c-index: 0.763 [0.714-0.812] vs. 0.735 [0.684-0.786] vs. 0.677 [0.604-0.749]; AUC: 0.736 vs. 0.714 vs. 0.628), indicating that RR had stronger prognostic power than post-IC DNA. Moreover, patients with stages III-IVRPA1 could benefit from high concurrent cumulative platinum dose (≥160 mg/m2). CONCLUSION: RR in conjunction with current TNM staging could better conduct risk stratification, prognosis prediction and help to guide precise concurrent chemotherapy.

Contrast-Enhanced Ultrasound Improves the Pathological Outcomes of US-Guided Core Needle Biopsy That Targets the Viable Area of Anterior Mediastinal Masses.

Based on the option that ultrasound-guided core needle biopsy (US-CNB) of the enhanced portion of anterior mediastinal masses (AMMs) identified by contrast-enhanced ultrasound (CEUS) would harvest viable tissue and benefit the histological diagnoses, a retrospective study was performed to elucidate the correlation between the prebiopsy CEUS and diagnostic yield of AMMs and found that CEUS potentially improved the diagnostic yield of AMMs compared with conventional US with a significant increase in the cellularity of samples. Furthermore, the marginal blood flow signals and absence of necrosis can predict the diagnostic yield of AMM. It was concluded that US-CNB of the viable part of AMMs, as verified by CEUS, was able to harvest sufficient tissue with more cellularity that could be used for ancillary studies and improve the diagnostic yield. And CEUS was recommended to those patients with AMMs undergoing repeated US-CNB, with the absence of marginal blood signals or presence of necrosis.

The prognostic impact of tumor volume on stage I non-small cell lung cancer.

OBJECTIVES: The purpose of this study was to investigate the prognostic impact of tumor volume (TV) on patients with stage I non-small cell lung cancer (NSCLC) after complete resection. MATERIALS AND METHODS: We retrospectively reviewed the clinicopathological characteristics of 274 patients with stage I NSCLC who had received preoperative chest computed tomography (CT) scans and complete resection. TV was semi-automatically measured from chest CT scans by using an imaging software program. The optimal cutoff values of TV were determined by X-tile software. Disease-free survival (DFS) and overall survival (OS) were compared using Kaplan-Meier analysis. Univariate and multivariate analyses were performed to identify risk factors for DFS and OS. RESULTS: By using 3.046cm3 and 8.078cm3 as two optimal cutoff values of TV, the patients were separated into three groups. The 5-year DFS and OS for patients with TV≤3.046cm3, 3.046-8.078cm3, and>8.078cm3 were 88.0%, 73.6%, and 62.1%, respectively (P<0.001), and 91.4%, 84.5%, and 73.3%, respectively (p<0.001). Multivariate analysis showed that age and TV were independent factors associated with DFS. Sex, age, histology, visceral pleural invasion, and TV were independent factors associated with OS. Stage Ia patients might be separated into three groups on the basis of TV with significantly different DFS and OS. Patients with tumor diameter≤2cm and 2-3cm were also stratified into two groups with significantly different DFS and OS on the basis of TV, respectively. CONCLUSION: TV is an independent risk factor for DFS and OS for stage I NSCLC after complete resection. TV might provide additional prognostic information over tumor diameter in patients with stage I NSCLC.

Value of CT-guided core-needle biopsy in diagnosis and classification of malignant lymphomas using automated biopsy gun.

AIM: To evaluate the value of CT-guided core-needle biopsy in diagnosis and classification of malignant lymphomas. METHODS: From January 1999 to October 2004, CT-guided core-needle biopsies were performed in 80 patients with suspected malignant lymphoma. Biopsies were performed with an 18-20 G biopsy-cut (CR Bard, Inc., Covington, GA, USA) needle driven by a spring-loaded Bard biopsy gun. RESULTS: A definite diagnosis and accurate histological subtype were obtained in 61 patients with a success rate of 76.25% (61/80). Surgical sampling was performed in 19 patients (23.75%) with non-diagnostic core-needle biopsies. The success rate of CT-guided core-needle biopsy varied with the histopathologic subtypes in our group. The relatively high success rates of core-needle biopsy were noted in diffuse large B-cell non-Hodgkin's lymphoma (NHL, 88.89%) and peripheral T-cell NHL (90%). However, the success rates were relatively low in anaplastic large cell (T/null cell) lymphoma (ALCL, 44.44%) and Hodgkin's disease (HD, 28.57%) in our group. CONCLUSION: CT-guided core-needle biopsy is a reliable means of diagnosing and classifying malignant lymphomas, and can be widely applied in the management of patients with suspected malignant lymphoma.

Reactive thymic hyperplasia following chemotherapy for children with lymphoma: computed tomography may be able to provide valuable information to avoid over-treatment.

OBJECTIVES: To analyse the clinical and computed tomography (CT) findings related to reactive thymic hyperplasia in order to improve the recognition of this phenomenon and avert over-treatment. METHODS: Fifty-two children with pathologically proven lymphoma developed reactive thymic hyperplasia following chemotherapy, which was confirmed with long-term review and follow-up. The clinical and CT findings of these 52 children were retrospectively analysed. RESULTS: The median follow-up period for the whole study group was 32.9 months. Fifty-one children survived free of disease; 23 of these had been with tumour invasion and the remaining 29 without. The median period from complete remission (CR) of the mediastinal lesions to the date of recurrent mediastinal masses was 8.6 months, which was not statistically significantly different from that of 9.5 months from commencement of treatment to the date of newly developed mediastinal masses (P = 0.495). The median maximal diameters of the recurrent and newly developed mediastinal masses were not significantly different (P = 0.091). All of the 52 cases presented with a single mediastinal mass; 42 masses (42/52, 81%) of those showed trapezoidal or triangular shapes and were well-circumscribed; 10 masses (10/52, 19%) manifested diffuse shapes and were ill-circumscribed. Forty-two masses (42/52, 81%) showed homogeneous density. All of the masses revealed mild enhancement after contrast administration. Forty-two masses (42/52, 81%) slightly displaced and 10 masses (10/52, 19%) partly surrounded adjacent vessels. After long-term follow-up, 42 masses (42/52, 81%) shrank naturally, and 10 (10/52, 19%) remained unchanged. CONCLUSIONS: Reactive thymic hyperplasia can, and often does, occur in children receiving regular chemotherapy for lymphoma, regardless of whether the tumour initially invades the mediastinum. Knowing the characteristic CT findings of this benign entity is helpful in differentiating it from residual or recurrent lymphoma and averting unnecessary treatment.

Multi-phasic CT arterial portography and CT hepatic arteriography improving the accuracy of liver cancer detection.

AIM: To evaluate the value of multi-phasic CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) in differential diagnosis of liver diseases, and to improve the specificity of CTAP and CTHA for liver cancer detection. METHODS: From January 1999 to December 2002, multi-phasic CTAP and CTHA were performed in 20 patients with suspected liver disease. CT scanning was begun 25 s, 60 s and 120 s for the early-, late- and delayed-phase CTAP examinations, and 6 sec, 40 s and 120 s for the early-, late- and delayed-phase CTHA examinations respectively, after a transcatheter arterial injection of non-ionic contrast material. If a lesion was diagnosed as a liver cancer, transcatheter hepatic arterial chemoembolization (TACE) treatment was performed, and the follow-up CT was performed three or four weeks later. RESULTS: All eighteen HCCs in 12 cases were shown as nodular enhancement on early-phasic CTHA. The density of the whole tumor decreased rapidly on late and delayed phases, and the edge of 12 tumors (12/18) remained relatively hyperdense compared with the surrounding liver tissue, and demonstrated as rim enhancement. All HCCs were shown as perfusion defect nodules on multi-phasic CTAP. Five tumors (5/18) were shown as rim enhancement on delayed-phasic CTAP. Rim enhancement was shown as 1 to 2-mm-wide irregular, uneven and discontinuous circumferential enhancement at late-, and delayed-phase of CTHA or CTAP. Five pseudolesions and 4 hemoangiomas were found in multi-phasic CTAP and CTHA. No pseudolesions and hemoangiomas were shown as rim enhancement on late- or delayed-phasic CTHA and CTAP. CONCLUSION: Multi-phasic CTAP and CTHA could help to recognize the false-positive findings in CTAP and CTHA images, and improve the accuracy of CTAP and CTHA of liver cancer detection.

Adrenal cortical adenoma with the maximal diameter greater than 5 cm: can they be differentiated from adrenal cortical carcinoma by CT?

To study the computed tomographic findings of adrenal adenoma with the maximal diameter greater than 5 cm and to discuss whether such tumor can be differentiated from adrenal carcinoma by CT examination. Fourteen consecutive patients with adrenal adenoma with the maximal diameter larger than 5 cm, proven pathologically, were enrolled. All patients underwent non-enhanced and contrast-enhanced CT examination. The CT findings, including size, shape, edge, density on non-enhanced CT and schedule of reinforcement after contrast administration for each lesion were retrospectively analyzed. CT data of 13 patients with adrenocortical carcinoma were also evaluated to determine whether differentiating characteristics existed. The maximal diameter of the 14 masses of adenoma ranged from 5.5 cm to 20 cm (mean, 10 cm). One mass showed lobulated, the rest 13 masses showed rounded or ovoid. Eleven and 3 masses appeared well-circumscribed and ill-circumscribed, respectively. All of 14 masses presented heterogeneous density on non-enhanced CT images with patchy low-attenuation foci or stippled calcification. All of 14 masses revealed moderately to markedly heterogeneous enhancement after contrast administration. None of 14 masses developed local invasion and distant metastasis. Except for recurrence, metastasis and venous tumor emboli which only occurred in the cases of adrenal carcinoma, no definite computed tomographic features could be found that enabled the identification of adenomas with the maximal diameter greater than 5 cm with adrenal carcinomas. The characteristic CT findings of adrenal adenoma with the maximal diameter greater than 5 cm include bulky, well-circumscribed, rounded or ovoid masses, heterogeneous attenuation with low-attenuation foci on non-enhanced CT images and heterogeneous enhancement after contrast administration. The differential diagnosis between such tumor and adrenal cortical carcinoma by CT examination is relatively difficult, such findings as recurrence, metastasis and venous tumor emboli may be of some significance.

MRI signal changes in the skull base bone after endoscopic nasopharyngectomy for recurrent NPC: a serial study of 9 patients.

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.

Primary nasopharyngeal non-Hodgkin's lymphoma: imaging patterns on MR imaging.

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.

Prospective study of tailoring whole-body dual-modality [18F]fluorodeoxyglucose positron emission tomography/computed tomography with plasma Epstein-Barr virus DNA for detecting distant metastasis in endemic nasopharyngeal carcinoma at initial staging.

PURPOSE: To evaluate which patients with nasopharyngeal carcinoma (NPC) obtained the greatest benefits from the detection of distant metastasis with [(18)F]fluorodeoxyglucose positron emission tomography and computed tomography (PET/CT) combined with plasma Epstein-Barr virus (EBV) DNA levels. PATIENTS AND METHODS: Consecutive patients with NPC were prospectively enrolled. PET/CT, conventional work-up (CWU), and quantification of plasma EBV DNA were performed before treatment. The accuracy of these strategies for distant metastases was assessed. The costs of the diagnostic strategies were compared. RESULTS: Eighty-six (14.8%) of the 583 eligible patients were found to have distant metastases; 71 patients (82.6%) by PET/CT and 31 patients (36.0%) by CWU. In the multivariable analysis, advanced N stage (odds ratio, 2.689; 95% CI, 1.894 to 3.818) and pretreatment EBV DNA level (odds ratio, 3.344; 95% CI, 1.825 to 6.126) were significant risk factors for distant metastases. PET/CT was not superior to CWU for detecting distant metastases in very low-risk patients (N0-1 with EBV DNA < 4,000 copies/mL; P = .062), but was superior for the low-risk patients (N0-1 with EBV DNA ≥ 4,000 copies/mL and N2-3 with EBV DNA < 4,000 copies/mL; P = .039) and intermediate-risk patients (N2-3 disease with EBV DNA ≥ 4,000 copies/mL; P < .001). The corresponding patient management changes based on PET/CT were 2.9%, 6.3%, and 16.5%, respectively. The costs per true-positive case detected by PET/CT among these groups were ¥324,138 (≈$47,458), ¥96,907 (≈$14,188), and ¥34,182 (≈$5,005), respectively. CONCLUSION: PET/CT detects more distant metastases than conventional staging in patients with NPC. The largest benefit in terms of cost and patient management was observed in the subgroup with N2-3 disease and EBV DNA ≥ 4,000 copies/mL.

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.

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-Hodgkin's 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 Kimura's disease. MATERIALS AND METHODS: The clinical data, CT and MRI findings of 15 patients with histologically proved Kimura's 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 Kimura's disease.

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.

[Correlation of multi-slice spiral CT features to clinicopathologic manifestations of gastrointestinal stromal tumor: a report of 49 cases].

BACKGROUND AND OBJECTIVE: Gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the digestive system. Imaging examination plays an important role in preoperative diagnosis and postoperative evaluation for it. This study was to describe the multi-slice spiral computed tomographic (MSCT) findings and pathologic features of GIST, and to analyze their correlation. METHODS: MSCT and pathologic reports of 49 patients with 53 pathologically confirmed GIST lesions were reviewed and compared. RESULTS: Of the 53 GIST lesions, 14 were at very low biological risk, 11 at low risk, ten at moderate risk and 18 at high risk; 36 (67.9%) were found in first visit by CT scans. On CT images, the GIST lesions with maximal diameter of > or =50 mm showed irregular shape, invasive growth, presence of cystic area and heterogeneous enhancement, and most of them were at high risk; the lesions with maximal diameter of <50 mm showed regular shape, expansive growth, and homogeneous enhancement, and most of them were at risk of moderate or below. No lymph node metastasis was found. Only three lesions showed S100-positive, which presented infiltration along the gastric wall or bowel ring on CT images. CONCLUSIONS: CT examination is helpful in risk prediction for GIST, but it is difficult to detect small lesions (< 2 cm) by CT scans. Due to the infiltrative growth of GIST with neural differentiation (S100-positive), it is difficult to distinguish GIST from gastric cancer on CT images.