Yunbin Chen

Impact of intensity-modulated radiotherapy on nasopharyngeal carcinoma: Validation of the 7th edition AJCC staging system

BACKGROUND AND PURPOSE The purpose of this study was to evaluate the 7th edition UICC/AJCC staging system for nasopharyngeal carcinoma (NPC) patients who were treated with intensity modulated radiation therapy (IMRT). MATERIALS AND METHODS The clinical data of 1241 NPC patients with initial magnetic resonance imaging (MRI) scans were studied retrospectively. All MRIs were independently reevaluated and restaged according to the 7th edition by two radiologists specializing in head and neck cancers. Analysis of prognostic factors in local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were performed. RESULTS The proportion of patients in Stage I, II, III, IVA and IVB were 4.8%, 26.2%, 45.4%, 18.4%, and 5.2%, respectively. The differences of LRFS between T1 and T2, and between T2 and T3 were not significant (P=0.055 and 0.605, respectively). Hazard ratios (HRs) for DSS and OS between T2 and T3 or between T3 and T4 differed significantly, but not between T1 and T2. The differences of DMFS between N0 and N1, between N1 and N2 were significant. However no significant difference was found in DMFS between N2 and N3a, or between N2 and N3b. For patients with T1-T3 disease, although skull base infiltration did not impact local failure, it was an independent prognostic factor for both distant failure and cancer death. CONCLUSION When treated with IMRT, the difference in the LRFS, DSS, and OS between T1 and T2 patients diminished, indicating that it is rational to merge T2 into T1. The prognostic value of the N classification of the current staging system had not changed much compared to the 6th edition.

Diffusion kurtosis imaging predicts neoadjuvant chemotherapy responses within 4 days in advanced nasopharyngeal carcinoma patients.

To explore the clinical value of diffusion kurtosis imaging (DKI) and monoexponential diffusion‐weighted imaging (DWI) for predicting early response to neoadjuvant chemotherapy (NAC) in patients with nasopharyngeal carcinoma (NPC).

Intravoxel Incoherent Motion-Magnetic Resonance Imaging as an Early Predictor of Treatment Response to Neoadjuvant Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma

AbstractThe aim of the study was to prospectively evaluate the clinical value of intravoxel incoherent motion (IVIM)-magnetic resonance imaging (MRI) in early predicting the treatment response to neoadjuvant chemotherapy (NAC) for nasopharyngeal carcinoma (NPC).Forty-eight patients with locoregionally advanced NPC were imaged with IVIM-MRI (14 b-factors, 0 – 1000 s/mm2) on a 3.0-T Magnetic resonance system, at the baseline, and repeatedly at the third and 21st day after NAC started. The IVIM-derived parameters (D, pure diffusion coefficient; f, perfusion fraction; and D*, pseudodiffusion coefficient) were calculated with the Interactive Data Language version 6.3 software. The baseline parameters and their corresponding changes (&Dgr;parameter(day)) during NAC were compared using the Student t test or Mann-Whitney U test. Variation analyses of IVIM-derived parameters were tested with intraclass correlation coefficient. Receiver-operating characteristic (ROC) curve analysis was conducted to estimate the best diagnostic accuracy. Statistical analyses were performed on the SPSS 18.0 software, with a 2-tailed probability value, P < 0.05 was considered significant.Among recruited patients, 37 cases were categorized as responders and 11 cases as nonresponders after NAC completed. The intra- and interobserver intraclass correlation coefficient of IVIM-derived parameters were excellent, which ranged from 0.858 to 0.971. Compared with the baseline value, at the third and 21st day, the D value was significantly higher and the D* value significantly lower (P < 0.05, P < 0.001, respectively). In contrast, f parameter only changed slightly (P > 0.05). Compared with nonresponders, responders presented a notably lower baseline D value and higher &Dgr;D3, &Dgr;D21, &Dgr;D3*, &Dgr;D21*, and &Dgr;f21 (P < 0.05), but no significant change in &Dgr;f3 was observed (P > 0.1). The receiver-operating characteristic curve analyses indicated that the threshold of baseline D values that best predicted the responders for primary nasopharynx tumors and metastatic lymph nodes were 0.911 × 10−3 mm2/s versus 0.951 × 10−3 mm2/s, and their corresponding area under curve, sensitivity, and specificity were 0.714 versus 0.774, 0.658 versus 0.538, and 0.818 versus 0.944, respectively.IVIM-MRI can potentially early predict the treatment response of NAC for NPC patients. The baseline D value, and early changes in D and D* value are better predictors of the chemotherapeutic responsiveness.

Early response to chemoradiotherapy for nasopharyngeal carcinoma treatment: Value of dynamic contrast‐enhanced 3.0 T MRI

To prospectively evaluate the dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) value for predicting early nasopharyngeal carcinoma (NPC) chemoradiotherapy (CRT) response.

Value of magnetic resonance diffusion-weighted imaging for the prediction of radiosensitivity in nasopharyngeal carcinoma.

Objective The effectiveness of radiotherapy in nasopharyngeal carcinoma (NPC) is closely related to the radiosensitivity of the carcinoma; however, there is currently no effective method to predict radiosensitivity in NPC. We explored the predictive value of magnetic resonance diffusion-weighted imaging (MR-DWI) for radiosensitivity in NPC. Study Design Prospective cohort study. Setting Single hospital. Subjects and Methods Patients with NPC who received intensity-modulated radiotherapy (IMRT) with or without chemotherapy were enrolled from April 2010 through November 2011. Primary tumor apparent diffusion coefficient (ADC) was measured before treatment (ADC0) and 2 weeks after the start of IMRT (ADC1). ADC change (ΔADC) was calculated as (ADC1 – ADC0)/ADC0 * 100%. Three months after the end of radiotherapy, the short-term effect of radiotherapy was assessed using the World Health Organization’s response evaluation criteria in solid tumors. Results Of 134 eligible NPC patients, 121 received combination chemotherapy. Three months after radiotherapy, residual local tumors were detected in 23 (17.2%) cases, and no residual tumors were detected in 111 (82.8%) cases. There was no significant difference in the residual tumor rates of patients receiving combination chemotherapy vs those who did not (P = 1.000). There were no significant differences in the ADC0 or ADC1 values of patients with and without residual tumors (P = .083 and .262). The ΔADC values of patients with (49.77% ± 31.02%) and without (68.35% ± 34.22%) residual tumors were significantly different (t = −2.406, P = .017). Logistic regression analysis indicated that ΔADC was an independent prognostic factor for the short-term effect of IMRT in NPC. Conclusion Magnetic resonance diffusion-weighted imaging may potentially have value for predicting radiosensitivity in NPC.

Early changes in apparent diffusion coefficients predict radiosensitivity of human nasopharyngeal carcinoma xenografts

Our objective was to predict the radiosensitivity of human nasopharyngeal carcinoma xenografts in nude mice models through an examination of early changes in apparent diffusion coefficient (ADC) values.

Automated Ki-67 Quantification of Immunohistochemical Staining Image of Human Nasopharyngeal Carcinoma Xenografts.

Nasopharyngeal carcinoma is one of the malignant neoplasm with high incidence in China and south-east Asia. Ki-67 protein is strictly associated with cell proliferation and malignant degree. Cells with higher Ki-67 expression are always sensitive to chemotherapy and radiotherapy, the assessment of which is beneficial to NPC treatment. It is still challenging to automatically analyze immunohistochemical Ki-67 staining nasopharyngeal carcinoma images due to the uneven color distributions in different cell types. In order to solve the problem, an automated image processing pipeline based on clustering of local correlation features is proposed in this paper. Unlike traditional morphology-based methods, our algorithm segments cells by classifying image pixels on the basis of local pixel correlations from particularly selected color spaces, then characterizes cells with a set of grading criteria for the reference of pathological analysis. Experimental results showed high accuracy and robustness in nucleus segmentation despite image data variance. Quantitative indicators obtained in this essay provide a reliable evidence for the analysis of Ki-67 staining nasopharyngeal carcinoma microscopic images, which would be helpful in relevant histopathological researches.

Suggestions for lymph node classification of UICC/AJCC staging system: a retrospective study based on 1197 nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy.

AbstractThis article provides suggestions for N classification of Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system of nasopharyngeal carcinoma (NPC), purely based on magnetic resonance imaging (MRI) in intensity-modulated radiation therapy (IMRT) era.A total of 1197 nonmetastatic NPC patients treated with IMRT were enrolled, and all were scanned by MRI at nasopharynx and neck before treatment. MRI-based nodal variables including level, laterality, maximal axial diameter (MAD), extracapsular spread (ECS), and necrosis were analyzed as potential prognostic factors. Modifications of N classification were then proposed and verified.Only nodal level and laterality were considered to be significant variables affecting the treatment outcome. N classification was thus proposed accordingly: N0, no regional lymph node (LN) metastasis; N1, retropharyngeal LNs involvement (regardless of laterality), and/or unilateral levels I, II, III, and/or Va involvement; N2, bilateral levels I, II, III, and/or Va involvement; and N3, levels IV, Vb, and Vc involvement. This proposal showed significant predicting value in multivariate analysis. N3 patients indicated relatively inferior overall survival (OS) and distant metastasis-free survival (DMFS) than N2 patients; however, the difference showed no statistical significance (P = 0.673 and 0.265 for OS and DMFS, respectively), and this was considered to be correlated with the small sample sizes of N3 patients (79 patients, 6.6%).Nodal level and laterality, but not MAD, ECS, and necrosis, were considered to be significant predicting factors for NPC. The proposed N classification was proved to be powerfully predictive in our cohort; however, treatment outcome of the proposed N2 and N3 patients could not differ significantly from each other. This insignificance may be because of the small sample sizes of N3 patients. Our results are based on a single-center data, to develop a new N classification that is universally acceptable; further verification by data from multicenter is warranted.

The prognosis of nasopharyngeal carcinoma involving masticatory muscles: a retrospective analysis for revising T subclassifications.

AbstractThis work is a retrospective study of magnetic resonance imaging (MRI) and T-stage subclassifications of nasopharyngeal carcinoma (NPC) involving the masticatory muscles (MMs). We examined how involvement of MMs influences the clinical T-stage classifications and the survival outcomes of NPC patients.MRI data as well as the medical records from 816 NPC patients were analyzed retrospectively. All cases were restaged according to the seventh edition of American Joint Committee on Cancer staging system criteria. The overall survival (OS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed by the Kaplan–Meier method, and their survival outcomes between different degrees of MM involvement and different T classifications were compared by using the log-rank test. All statistical analyses were conducted on SPSS 18.0 software. P > 0.05 was considered significant.Of the 816 NPC patients analyzed, 283 (34.68%) had tumors that involved MMs. All of those 283 patients involved the medial pterygoid muscle, and 125 cases (15.32%) involved the lateral pterygoid muscle. Multivariate analysis identified MM involvement as an independent prognostic factor for patients OS (P = 0.007) and LRFS (P = 0.024). MM involvement significantly correlated with a lower OS and LRFS (P < 0.01). In addition, compared with concurrent involvement of the medial and lateral pterygoid muscle, the medial pterygoid muscle involvement correlated with a higher OS and LRFS (P < 0.05). Among NPC patients, T-classifications 1 to 4 usually predicted the ultimate OS, LRFS, and DMFS (P > 0.1), unless the cancer involved the lateral pterygoid muscle.NPC involving the lateral pterygoid muscle presents a worse survival outcome than that involving the medial pterygoid muscle. Any cancer involving the lateral pterygoid muscle should be classified in a higher T-stage subclassification.

Parotid area lymph node metastases from preliminarily diagnosed patients with nasopharyngeal carcinoma: report on tumor characteristics and oncologic outcomes

The parotid area lymph node (PLN) is an uncommon site of metastasis originating from nasopharyngeal carcinoma (NPC). The study aimed to investigate clinical characteristics and outcomes of patients with preliminarily diagnosed NPC with PLN metastases. Here we retrospectively reviewed Magnetic resonance imaging (MRI) scans of 2221 patients with untreated nonmetastatic NPC who received intensity-modulated radiation therapy (IMRT). Finally, 64 (2.9%) patients were identified with PLN metastases, of which, 34 received PLN-sparing IMRT and 30 received PLN-radical IMRT. We also found that 42.2% had N3 disease and 95.3% had stages III-IVb. PLN metastases on MRI were characterized by ipsilateral retropharyngeal lymph node (RLN) or level II nodal extracapsular spread (ECS), ipsilateral giant cervical nodes, ipsilateral parapharyngeal extension, or solitary parotid metastasis. The 5-year overall survival, distant metastasis-free survival, regional relapse-free survival, and parotid relapse-free survival rates were 70.4%, 64.3%, 76.7%, and 87.9%, respectively. Distant metastases were the main cause of treatment failure and death. Using PLN-sparing IMRT, sparing PLN with minimal axial diameter of <10 mm, could increase the risk of parotid recurrence. However, it was not an independent prognostic factor. N classification and concurrent-based chemotherapy were almost statistically significant for distant failure and death. Overall, we demonstrated that the PLN metastases might be derived from RLN or level II nodal ECS, giant cervical nodes in a retrograde fashion, or parapharyngeal extension. Sparing PLN of <10 mm by IMRT should consider the risk of parotid recurrence. Distant metastases remained the dominant treatment failure. Further effective systemic chemotherapy should be explored.