Establishment and Validation of a Novel MRI Radiomics Feature-Based Prognostic Model to Predict Distant Metastasis in Endemic Nasopharyngeal Carcinoma.

Purpose: We aimed to establish a prognostic model based on magnetic resonance imaging (MRI) radiomics features for individual distant metastasis risk prediction in patients with nasopharyngeal carcinoma (NPC). Methods: Regression analysis was applied to select radiomics features from T1-weighted (T1-w), contrast-enhanced T1-weighted (T1C-w), and T2-weighted (T2-w) MRI scans. All prognostic models were established using a primary cohort of 518 patients with NPC. The prognostic ability of the radiomics, clinical (based on clinical factors), and merged prognostic models (integrating clinical factors with radiomics) were identified using a concordance index (C-index). Models were tested using a validation cohort of 260 NPC patients. Distant metastasis-free survival (DMFS) were calculated by using the Kaplan-Meier method and compared by using the log-rank test. Results: In the primary cohort, seven radiomics prognostic models showed similar discrimination ability for DMFS to the clinical prognostic model (P=0.070-0.708), while seven merged prognostic models displayed better discrimination ability than the clinical prognostic model or corresponding radiomics prognostic models (all P<0.001). In the validation cohort, the C-indices of seven radiomics prognostic models (0.645-0.722) for DMFS prediction were higher than in the clinical prognostic model (0.552) (P=0.016 or <0.001) or in corresponding merged prognostic models (0.605-0.678) (P=0.297 to 0.857), with T1+T1C prognostic model (based on Radscore combinations of T1 and T1C Radiomics models) showing the highest C-index (0.722). In the decision curve analysis of the validation cohort for all prognostic models, the T1+T1C prognostic model displayed the best performance. Conclusions: Radiomics models, especially the T1+T1C prognostic model, provided better prognostic ability for DMFS in patients with NPC.

MRI-based radiomics models can improve prognosis prediction for nasopharyngeal carcinoma with neoadjuvant chemotherapy.

BACKGROUND: The purpose of this study was to explore the prognostic value of imaging features and related models in nasopharyngeal carcinoma (NPC) patients that received neoadjuvant chemotherapy. MATERIALS AND METHODS: We systematically reviewed the data of 110 NPC patients who received radiotherapy and neoadjuvant chemotherapy. The patients were randomly divided into the training cohort (n = 88) and the verification cohort (n = 22). The imaging data collected in this study were screened via Pyramidics and used to construct prediction models based on histology and clinical nomographs. The models' accuracy was evaluated via calibration curves and the consistency index (C-index). In addition, we also explored the correlation between radiomics expression patterns, quantitative histological characteristics, and clinical data and then constructed a model to predict the prognosis of NPC. RESULTS: The models that integrated radiomics contours with all the clinical data were superior to those based on the clinical data alone (C-index 0.746 vs. C-index 0.814, respectively) and the calibration curves showed good consistency. The heat map showed that the radiomics expression pattern and selected histological characteristics were correlated with the clinical stage, T stage, and N stage (p < 0.05), and no radiomics feature was associated with lactate dehydrogenase expression, lymphocyte count, or mononuclear cell count. CONCLUSION: MRI-based radiomics can significantly improve the efficacy of traditional TNM staging and clinical data in predicting the progression-free survival (PFS) of patients with advanced NPC, which may provide an opportunity for precision medicine.

The Effect of Previous Irradiation for Patients With Prosthetic Breast Reconstruction: A Meta-Analysis.

BACKGROUND: Results regarding immediate prosthetic breast reconstruction after postmastectomy radiation therapy (PMRT) have been inconsistent. OBJECTIVES: The authors aimed to assess the efficacy and safety of PMRT before immediate prosthetic breast reconstruction for patients with breast cancer. METHODS: Electronic databases (PubMed, EmBase, and the Cochrane Library) were systematically searched to identify eligible studies from their inception until March 2020. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was applied as an effect estimate and calculated using the random-effects model. RESULTS: Nineteen studies including a total of 6757 patients were selected for final meta-analysis. The pooled OR showed that PMRT was associated with a higher incidence of reconstruction failure (OR = 2.57; 95% CI =1.55-4.26; P < 0.001), capsular contracture (OR = 5.99; 95% CI = 3.12-11.47; P < 0.001), and overall complications (OR = 2.52; 95% CI = 1.68-3.79; P < 0.001). It was also associated with a lower incidence of patient satisfaction (OR = 0.29; 95% CI = 0.16-0.52; P < 0.001) and good aesthetic results (OR = 0.25; 95% CI = 0.12-0.52; P < 0.001) compared with those who did not undergo PMRT. These significant associations could be affected by study design, mean age, stage of immediate breast reconstruction, follow-up, and study quality. CONCLUSIONS: Although PMRT is the standard adjuvant therapy for mastectomy patients treated with immediate implant-based breast reconstruction, PMRT for patients undergoing immediate implant-based breast reconstruction has been associated with high risks of reconstruction failure, capsular contracture, and overall complications as well as low incidences of patient satisfaction and good aesthetic results.

Correction to: Radiomics on multi-modalities MR sequences can subtype patients with non-metastatic nasopharyngeal carcinoma (NPC) into distinct survival subgroups.

The original version of this article, published on 14 March 2019, unfortunately contained a mistake.

Radiomics on multi-modalities MR sequences can subtype patients with non-metastatic nasopharyngeal carcinoma (NPC) into distinct survival subgroups.

OBJECTIVES: To explore and evaluate the feasibility of radiomics in stratifying nasopharyngeal carcinoma (NPC) into distinct survival subgroups through multi-modalities MRI. METHODS: A total of 658 patients (training cohort: 424; validation cohort: 234) with non-metastatic NPC were enrolled in the retrospective analysis. Each slice was considered as a sample and 4863 radiomics features on the tumor region were extracted from T1-weighted, T2-weighted, and contrast-enhanced T1-weighted MRI. Consensus clustering and manual aggregation were performed on the training cohort to generate a baseline model and classification reference used to train a support vector machine classifier. The risk of each patient was defined as the maximum risk among the slices. Each patient in the validation cohort was assigned to the risk model using the trained classifier. Harrell's concordance index (C-index) was used to measure the prognosis performance, and differences between subgroups were compared using the log-rank test. RESULTS: The training cohort was clustered into four groups with distinct survival patterns. Each patient was assigned to one of the four groups according to the estimated risk. Our method gave a performance (C-index = 0.827, p < .004 and C-index = 0.814, p < .002) better than the T-stage (C-index = 0.815, p = .002 and C-index = 0.803, p = .024), competitive to and more stable than the TNM staging system (C-index = 0.842, p = .003 and C-index = 0.765, p = .050) in the training cohort and the validation cohort. CONCLUSIONS: Through investigating a large one-institutional cohort, the quantitative multi-modalities MRI image phenotypes reveal distinct survival subtypes. KEY POINTS: • Radiomics phenotype of MRI revealed the subtype of nasopharyngeal carcinoma (NPC) patients with distinct survival patterns. • The slice-wise analysis method on MRI helps to stratify patients and provides superior prognostic performance over the TNM staging method. • Risk estimation using the highest risk among slices performed better than using the majority risk in prognosis.

TCR repertoire profiling of tumors, adjacent normal tissues, and peripheral blood predicts survival in nasopharyngeal carcinoma.

The T-cell immune responses in nasopharyngeal carcinoma patients have been extensively investigated recently for designing adoptive immunotherapy or immune checkpoint blockade therapy. However, the distribution characteristics of T cells associated with NPC pathogenesis are largely unknown. We performed deep sequencing for TCR repertoire profiling on matched tumor/adjacent normal tissue from 15 NPC patients and peripheral blood from 39 NPC patients, 39 patients with other nasopharyngeal diseases, and 33 healthy controls. We found that a lower diversity of TCR repertoire in tumors than paired tissues or a low similarity between the paired tissues was associated with a poor prognosis in NPC. A more diverse TCR repertoire was identified in the peripheral blood of NPC patients relative to the controls; this was related to a significant decrease in the proportion of high-frequency TCR clones in NPC. Higher diversity in peripheral blood of NPC patients was associated with a worse prognosis. Due to the peculiarity of the Vß gene usage patterns in the peripheral blood of NPC patients, 15 Vß genes were selected to distinguish NPC patients from controls by the least absolute shrinkage and selection operator analysis. We identified 11 clonotypes shared by tumors and peripheral blood samples from different NPC patients, defined as "NPC-associated" that might have value in adoptive immunotherapy. In conclusion, we here report the systematic and overall characteristics of the TCR repertoire in tumors, adjacent normal tissues, and peripheral blood of NPC patients. The data obtained may be relevant to future clinical studies in the setting of immunotherapy for NPC patients.

Changes of plasma cytokines and chemokines expression level in nasopharyngeal carcinoma patients after treatment with definitive intensity-modulated radiotherapy (IMRT).

BACKGROUND: Potential clinical application values of certain cytokines and chemokines that participate in the process of tumor growth, invasion, and metastasis have been reported. However, there still lack of biomarkers for a great many of malignancy. This study identified cytokines or chemokines involved in the occurrence and development of nasopharyngeal carcinoma (NPC), which might be a biomarker for noninvasive early diagnosis. METHODS: The plasma levels of 19 cytokines and chemokines were detected by the luminex liquid array-based multiplexed immunoassays in 39 NPC patients before and after treatment by definitive intensity-modulated radiotherapy (IMRT). RESULTS: Plasma levels of almost all of the 19 cytokines and chemokines in NPC patients were higher than healthy controls, while only IFN-γ, IL-1b IL-6, MCP-1, TNF-α, FKN, IL-12P70, IL-2, IL-5 and IP-10 showed significant differences. However, expression levels of most of the 19 cytokines and chemokines decreased after therapy, especially IFN-γ, IL-10, IL-1b, IL-6, IL-8, MCP-1, TNF-α, VEGF, IL-17A, IL-2, IL-5 and MIP-1b, have a dramatic decline. Taking together, plasma levels of IFN-γ, IL-1b, IL-6, MCP-1, TNF-α, IL-2 and IL-5 are significantly increased in NPC patients and dramatically decreased after treatment, suggesting these cytokines and chemokines might play important roles in the progress of NPC. More interestingly, the expression level of MPC-1 is significantly associated with clinical stage. CONCLUSION: MCP-1 might involve in the genesis and development process of NPC, which might serve as a noninvasive biomarker for early diagnosis.

Can Parameters Other than Minimal Axial Diameter in MRI and PET/CT Further Improve Diagnostic Accuracy for Equivocal Retropharyngeal Lymph Nodes in Nasopharyngeal Carcinoma?

PURPOSE: Minimal axial diameter (MIAD) in magnetic resonance imaging (MRI) was recognized as the most useful parameter in diagnosing lateral retropharyngeal lymph (LRPL) nodes in nasopharyngeal carcinoma (NPC). This study aims to explore the additional nodal parameters in MRI and positron emission tomography-computed tomography for increasing the prediction accuracy. MATERIALS AND METHODS: A total of 663 LRPL nodes were retrospectively collected from 335 patients with NPC. The LRPL nodes ascertained on follow-up MRI were considered positive for metastases. First, the optimal cutoff value of each parameter was derived for each parameter. In addition, neural network (NN) nodal evaluation was tested for all combinations of three parameters, namely MIAD, maximal axial diameter (MAAD), and maximal coronal diameter (MACD). The optimal approach was determined through brute force attack, and the results of two methods were compared using a bootstrap sampling method. Second, the mean standard uptake value (NSUVmean) was added as the fourth parameter and tested in the same manner for 410 nodes in 219 patients. RESULTS: In first and second analysis, the accuracy rate (percentage) for the MIAD was 89.0% (590/663) and 89.0% (365/410), with the optimal cutoff values being 6.1 mm and 6.0 mm, respectively. With the combination of all three and four parameters, the accuracy rate of the NN was 89% (288/332) and 88.8% (182/205), respectively. In prediction, the optimal combinations of the three and four parameters resulted in correct identification of three (accuracy: 593/663, 89.4%) and six additional nodes (371/410, 90.5%), representing 4% (3/73) and 13.3% (6/45) decreases in incorrect prediction, respectively. CONCLUSION: NPC LRPL nodes with an MIAD ≥ 6.1 mm are positive. Among nodes with an MIAD < 6.1 mm, if the NSUVmean ≥ 2.6 or MACD ≥ 25 mm and MAAD ≥ 8 mm, the nodes are positive; otherwise, they are negative.

Pretreatment Diffusion-Weighted MRI Can Predict the Response to Neoadjuvant Chemotherapy in Patients with Nasopharyngeal Carcinoma.

PURPOSE: To explore the potential of diffusion-weighted (DW) magnetic resonance imaging (MRI) using apparent diffusion coefficient (ADC) for predicting the response to neoadjuvant chemotherapy in nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Ninety-two consecutive patients with NPC who underwent three cycles of neoadjuvant chemotherapy were retrospectively analyzed. DW and anatomical MRI were performed before and after neoadjuvant chemotherapy prior to radiotherapy. Pretreatment ADCs and percentage increases in ADC after chemotherapy were calculated for the primary lesions and metastatic adenopathies. Receiver operating characteristic curve analysis was used to select optimal pretreatment ADCs. RESULTS: Pretreatment mean ADCs were significantly lower for responders than for nonresponders (primary lesions, P = 0.012; metastatic adenopathies, P = 0.013). Mean percentage increases in ADC were higher for responders than for nonresponders (primary lesions, P = 0.008; metastatic adenopathies, P < 0.001). The optimal pretreatment primary lesion and metastatic adenopathy ADCs for differentiating responders from nonresponders were 0.897 × 10(-3) mm(2)/sec and 1.031 × 10(-3) mm(2)/sec, respectively. CONCLUSIONS: NPC patients with low pretreatment ADCs tend to respond better to neoadjuvant chemotherapy. Pretreatment ADCs could be used as a new pretreatment imaging biomarker of response to neoadjuvant chemotherapy.

Prognostic value of classifying parapharyngeal extension in nasopharyngeal carcinoma based on magnetic resonance imaging.

PURPOSE: To subclassify parapharyngeal extension in nasopharyngeal carcinoma (NPC) and investigate its prognostic value and staging categories based on magnetic resonance imaging (MRI). METHODS AND MATERIALS: Data from 1504 consecutive NPC patients treated with definitive-intent radiotherapy were analyzed retrospectively. Sites of parapharyngeal extension were defined by MRI. Overall survival (OS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were calculated by the Kaplan-Meier method and compared with the log-rank test. Hazard consistency and hazard discrimination were determined by multivariate analysis with Cox proportional hazards models. RESULTS: 1104 patients (73.4%) had parapharyngeal extension; 1.7-63.8% had involvement of various anatomic sites. The hazard ratio for death was significantly higher with extensive parapharyngeal extension (lateral pterygoid muscle of masticator space and beyond or parotid space) than with mild extension (medial pterygoid muscle of masticator space, or carotid, prestyloid, and prevertebral or retropharyngeal space). OS, LRFS, and DMFS with extensive parapharyngeal extension were similar to those in T4 disease; OS, LRFS, and DMFS with mild parapharyngeal extension were significantly higher than in those T3 disease (all P ≤ 0.015). CONCLUSIONS: Parapharyngeal extension in NPC should be subclassified as mild or extensive, which should be regarded as stages T2 and T4 diseases, respectively.

Prognostic value of grading masticator space involvement in nasopharyngeal carcinoma according to MR imaging findings.

PURPOSE: To derive a suitable method for grading masticator space invasion in nasopharyngeal carcinoma on the basis of magnetic resonance (MR) images and to determine its prognostic value in patients undergoing intensity-modulated radiation therapy. MATERIALS AND METHODS: After institutional review board approval and informed consent were acquired, 808 patients with nasopharyngeal carcinoma who were treated with definitive intensity-modulated radiation therapy were analyzed retrospectively. The anatomic sites of masticator space involvement were identified with MR imaging. Overall survival, local relapse-free survival, and distant metastasis-free survival were calculated by using the Kaplan-Meier method and were compared by using the log-rank test. Potential prognostic factors were identified by means of multivariate analysis. RESULTS: Masticator space involvement was diagnosed in 163 of 808 patients (20.2%). Patients with lateral invasion (involvement of the lateral pterygoid muscle of the masticator space and beyond) had significantly poorer overall survival and distant metastasis-free survival than those with medial invasion (involvement of the medial pterygoid muscle of the masticator space) (P = .035 and P = .026, respectively). Furthermore, their overall survival, local relapse-free survival, and distant metastasis-free survival were significantly poorer compared with patients with stage T2 or T3 disease (all P ≤ .023) but similar to patients with stage T4 disease. The grade of masticator space involvement was an independent prognostic factor for overall survival, local relapse-free survival, and distant metastasis-free survival (all P ≤ .023). CONCLUSION: Masticator space involvement in nasopharyngeal carcinoma should be graded as medial (stage T2 disease) or lateral (stage T4 disease). This can facilitate staging of nasopharyngeal carcinoma and may be a suitable prognostic indicator of survival.

[Comparison of ultraviolet A and ultraviolet B on 1,25-dihydroxy-vitamin D3 and bone metabolism in ovariectomized rats].

OBJECTIVE: To investigate the effects of ultraviolet A (UVA) and ultraviolet B (UVB) on serum 1,25-dihydroxy-vitamin D3 and bone metabolism of ovariectomized rats and to compare them on bone metabolism. METHODS: In the study, 40 six-month female Sprague-Dawley rats were randomly divided into sham-operated control group (sham), osteoporosis model group (OVX), UVA irradiation group (OVX+UVA) and UVB irradiation group (OVX+UVB). Except the sham-operated control group, the remaining rats were ovariectomized to establish the osteoporosis models. After the model establishment, the UVA and UVB groups were exposed to UV irradiation with wavelengths of 340 nm and 313 nm, respectively. After the 15-week UV irradiation treatment, bone material density and serum 1,25(OH)2D3, osteocalcin (bone gamma-carboxyglutamic acid protein, BGP), calcium (Ca) and phosphorus (P) contents were measured. RESULTS: Compared with the sham group, the body weights [(486.5±55.7) g, (488.3±32.1) g, (494.1±49.8) g, vs. (408.6±36.1) g, P<0.01] were significantly higher in the model group, UVA group and UVB group; proximal femur BMD [(0.318±0.025) g/cm(2), (0.316±0.031) g/cm(2), (0.322±0.036) g/cm(2), vs.(0.386±0.027) g/cm(2), P<0.01], central BMD [(0.321±0.038) g/cm(2), (0.319±0.051) g/cm(2), (0.320±0.053) g/cm(2), vs.(0.347±0.044) g/cm(2), P<0.05], distal femur BMD [(0.320±0.028) g/cm(2), (0.318±0.030) g/cm(2), (0.322±0.036) g/cm(2), vs.(0.361±0.046) g/cm(2), P<0.01] were significantly lower in the model group, UVA group and UVB group. After the 15-week treatment of UV radiation, compared with the sham group, proximal femur BMD [(0.162±0.125) g/cm(2) vs.(0.293±0.076) g/cm(2), P<0.01], central BMD [(0.205±0.102) g/cm(2) vs.(0.306±0.031) g/cm(2), P<0.01] , distal femur BMD [(0.153±0.119) g/cm(2) vs.(0.274±0.017) g/cm(2), P<0.01] were significantly decreased in the model group; serum 1,25(OH)2D3 [(19.80±1.67) ng/L vs. (28.35±4.32) ng/L, P<0.01], BGP [(11.00±0.01) ng/L vs.(16.64±0.01) ng/L,P<0.01] and Ca [(2.14±0.10) mmol/L vs.(2.68±0.16) mmol/L,P<0.01] were significantly lower in the model group. Compared with the model group, proximal femur BMD [(0.248±0.092) g/cm(2), (0.218±0.123) g/cm(2), vs.(0.162±0.125) g/cm(2), P<0.01], central BMD [(0.272±0.010) g/cm(2), (0.275±0.036) g/cm(2), vs.(0.205±0.102) g/cm(2), P<0.01] and distal femur BMD [(0.251±0.009) g/cm(2), (0.242±0.063) g/cm(2), vs.(0.153±0.119) g/cm(2), P<0.01] were significantly increased in the UVA group and UVB group; serum 1,25(OH)2D3 [(29.47±4.54) ng/L, (27.56±6.33) ng/L, vs.(19.80±1.67) ng/L, P<0.01], BGP[(15.70±0.01)ng/L, (15.62±0.02) ng/L, vs.(11.00±0.01) ng/L, P<0.01] and Ca [(2.48±0.22) mmol/L, (2.58±0.13) mmol/L, vs.( 2.14±0.10) mmol/L, P<0.01] were significantly higher in the UVA group and UVB group. There were no statistical differences among the UVA group, UVB group and sham group. CONCLUSION: Both UVA and UVB may improve serum 1,25(OH)2D3 content of ovariectomized rats, promote bone formation, increase bone material density, and relieve bone loss due to osteoporosis.

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.

Concurrent weekly docetaxel chemotherapy in combination with radiotherapy for stage III and IVA-B nasopharyngeal carcinoma.

BACKGROUND AND PURPOSE: Cisplatin is the most common chemotherapeutic agent for loco-regionally advanced nasopharyngeal carcinoma (NPC); however, toxicity is a limiting factor for some patients. We retrospectively compared the efficacy and toxicity of weekly docetaxel-based and cisplatin-based concurrent chemoradiotherapy in loco-regionally advanced NPC. METHODS AND MATERIALS: Eighty-four patients with Stage III and IVA-B NPCs, treated between 2007 and 2008, were retrospectively analyzed. Thirty received weekly docetaxel-based concurrent chemotherapy, and 43 were given weekly cisplatin-based concurrent chemotherapy. Radiotherapy was administered using a conventional technique (seven weeks, 2.0 Gy per fraction, total dose 70-74 Gy) with 6-8 Gy boosts for some patients with locally advanced disease. RESULTS: Median follow-up time was 42.3 months (range, 8.6-50.8 months). There were no significant differences in the 3-year loco-regional failure-free survival (85.6% vs. 92.3%; p=0.264), distant failure-free survival (87.0% vs. 92.5%; p=0.171), progression-free survival (85.7% vs. 88.4%; p=0.411) or overall survival (86.5% vs. 92.5%, p=0.298) of patients treated concurrently with docetaxel or cisplatin. Severe toxicity was not common in either group. CONCLUSIONS: Weekly docetaxel-based concurrent chemoradiotherapy is potentially effective and has a tolerable toxicity; however, further investigations are required to determine if docetaxel is superior to cisplatin for advanced stage NPC.

Primary nasopharyngeal adenocarcinoma: a review.

Primary nasopharyngeal adenocarcinoma (NAC) accounts for approximately 0.5% of all nasopharyngeal cancer. The diagnosis, staging and treatment of NAC has not been well described. This article presents a literature review on NAC and identifies its characteristics and management. The NAC group of diseases contains various pathological types and has a series of specific clinical characteristics, including slow progression, a low incidence of neck masses and frequent cranial neuropathy. The Epstein-Barr virus may not play an important role in NAC carcinogenesis. The rarity of the disease makes the staging classification and treatment strategies of NAC parallel to those recommended for nasopharyngeal squamous carcinoma. Some patients might benefit from surgery, and radiotherapy using precise techniques might achieve good control for treating NAC, but the roles of chemotherapy and target therapy are not clear. The proper staging system and optimal treatment strategies need to be established in NAC.

Radiologic criteria of retropharyngeal lymph node metastasis in nasopharyngeal carcinoma treated with radiation therapy.

PURPOSE: To determine the appropriate radiologic criteria of metastatic retropharyngeal lymph nodes (RLNs) in patients with nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: After institutional review board approval and informed consent, 303 consecutive NPC patients treated with definitive radiation therapy were examined after completion of therapy. RLNs were classified as metastatic on the basis of the results of magnetic resonance (MR) imaging follow-up.The receiver operating characteristic curve and area under the curve were determined to assess the accuracy of different size criteria in the diagnosis of RLN metastasis. RESULTS: Initial MR images revealed 523 RLNs in 265 patients. Two hundred sixty-four (50.5%) RLNs positive for malignant involvement were confirmed in 177 patients. The remaining 259 (49.5%) nodes were classified as negative for benign process at follow-up. The minimal axial diameter was found to be more accurate than the maximal axial diameter for assessing metastatic RLNs. The most accurate size criterion of metastatic RLNs was a minimal axial diameter of 6 mm or larger, resulting in an accuracy of 87.5% (457 of 522). Central necrosis or groups of two or more of RLNs had a 100% specificity for diagnosis of RLN metastases. CONCLUSION: The radiologic criteria that should be used for assessment of RLN metastases in NPC patients are nodes with a minimal axial diameter 6 mm or larger, any node with central necrosis, groups of two or more RLNs, or any medial RLN; these criteria may be useful in tumor staging and treatment planning.

[Application of 99mTc-DTPA in evaluation of blood-brain barrier permeability in patients receiving whole brain irradiation].

OBJECTIVE: To study the pattern of blood-brain barrier (BBB) permeability changes during whole brain radiotherapy (WBRT) for metastatic brain tumor. METHODS: Twenty patients with metastatic brain tumors receiving WBRT by 6 MV X-ray underwent (99)mTc-DTPA brain SPECT before and during WBRT (20, 40 Gy) and at 2 weeks after the end of irradiation. A frame of transverse (99)mTc-DTPA brain SPECT image that best displayed the brain metastasis was chosen, and the regions of interest (ROI) were defined in the tumor foci (T), the contralateral normal brain tissue (N) and the background outside the soft tissues around the cranium (B). The radioactive counts of every ROI were measured and the ratios of the total counts (T/B and N/B) before and during WBRT (20 Gy, 40 Gy) and at 2 weeks after the irradiation were calculated. RESULTS: The average T/B and N/B in the 20 patients with 30 brain metastases was 142.2-/+51.1 and 82.6-/+42.3 before WBRT, 260.3-/+121.5 and 150.7-/+72.5 during 20 Gy WBRT, 251.6-/+118.3 and 161.8-/+68.4 during 40 Gy WBRT, and 250.3-/+117.2 and 158.6-/+73.5 at 2 weeks after the irradiation, respectively. The measurements during WBRT (20 and 40 Gy) and at 2 weeks after the irradiation group underwent no significant variations (P>0.05), but showed significant differences from those before WBRT (P<0.05). CONCLUSIONS: Irradiation causes direct damage of the BBB function, and the permeability of the BBB increases significantly during and within 2 weeks following 20 and 40 Gy WBRT, which provides the optimal time window for interventions with chemotherapy.

A case of zonal syringocystadenoma papilliferum of the axilla mimicking verruca vulgaris.

Syringocystadenoma papilliferum (SCAP) most frequently arises from an organoid nevus on the head and neck. Zonal or segmental lesions occurring in other locations are rare. Here, we report a case of a 39-year-old woman with an SCAP clinically mimicking verruca vulgaris in a zonal distribution on her right axilla after her birth. Histopathologic examination showed it to be a typical SCAP. Furthermore, the tumor had a warty surface, which histologically revealed some signs of viral infection. Although polymerase chain reactions for low- and high-risk human papilloma virus types were negative, the relationship of SCAP with viral infection needs further investigation.

[Distributions of primary nasopharyngeal carcinoma tumor and patterns of skull base erosion detected by magnetic resonance imaging].

OBJECTIVE: To evaluate the distributions of primary nasopharyngeal carcinoma (NPC) and the patterns of skull base involvement in NPC patients using magnetic resonance imaging (MRI). METHODS: After the approval of institutional review board and informed consent, 838 consecutive newly-diagnosed and untreated NPC patients were examined by MRI. Their MR images were reviewed by two independent radiologists. RESULTS: Among all cases, the incidence rates of superior side and post-superior side involvement were 98.57% (826/838) and 98.21% (823/838) respectively. The differences were not significant between these two sides (P > 0.05). Lateral side erosion was demonstrated in 784 (93.56%) cases. Posterior side was involved in 391 (46.66%) cases. The total incidence rate of skull base involvement was 65.51% (549/838). According to the anatomic site, the pathways of skull base involvement were classified into 5 spreading routes: anterior; superior; super-lateral; super-anterior and super-posterior. According to the incidence rates and the results of chi-square test, the anatomic sites around the nasopharynx were classified into three groups of risk grades: high-risk (≥ 35%), medium-risk (≥ 5% - 35%) and low-risk (< 5%). CONCLUSION: Skull base involvement of NPC spreads stepwise from proximal site to more distal sites. The area of skull base involvement in NPC is classified into high-grade, medium-grade and lower-grade groups respectively. The high and medium-grade groups are related with T3 stage while the lower-grade group T4 stage. Thus T3 stage should be subdivided into T3a and T3b. These schemes may be useful in a more accurate NPC staging and a delineation of clinical target volume for radiotherapy in NPC patients.