Volumetric analysis of tumor extent in nasopharyngeal carcinoma and correlation with treatment outcome

Patterns of failure in patients with nasopharyngeal cancer of Northeastern region of India: a retrospective observational study

PURPOSE

We aimed to analyze patterns of failure and disease volume-treatment outcomes in patients with Nasopharyngeal carcinoma (NPC) treated with definitive radiation with or without concurrent chemotherapy at a tertiary cancer centre in northeast India.

METHODS

From February 2018 to February 2022, 99 histopathologically proved non-metastatic NPC patients treated with curative-intent RT with or without chemotherapy were retrospectively analyzed. Locally advanced patients received neoadjuvant or adjuvant chemotherapy. The Cox proportional hazards model was used to investigate the impact of various prognostic factors on locoregional free survival (LRFS), distant metastasis free survival (DMFS), progression free survival (PFS) and overall survival (OS). The log-rank test and Kaplan-Meir curves compared outcome variables based on ROC analysis-classified tumor volume.

RESULTS

During a median follow up of 25.4 months (17.3-39.2), 35(35.4%) patients developed recurrence. Twenty-three patients developed locoregional failures, of which 11 were in-field; 12 patient showed an out-field failure. The 3-year LRFS, DMFS, PFS and OS was 71.10%, 70.90%, 64.10% and 74.10% respectively. There was statistically significant difference in LRFS according to T staging (p < 0.0001). Gross tumor volume (GTVp) and gross nodal volume (GTVn) were an independent prognostic factor for OS, PFS, LRFS and DMFS. The cut-off volumes for GTVp and GTVn for distant metastases and locoregional failure, respectively, were found to be 13 and 22.7 mL and 3.7 and 39.2 mL, respectively, by ROC curve analysis. Based on this, 99 patients were divided into three subgroups. OS demonstrated significant differences among patients in different volume subgroups for GTVp (p = 0.03) and GTVn (p = 0.00024).

CONCLUSIONS

For NPC patients who undergo curative IMRT, primary tumour and nodal volumes are independent prognostic indicators. GTVp and GTVn are highly predictive of local control, distant metastases, disease-free survival, and overall survival. This justifies their use as quantitative prognostic indicator for NPC.

A Prospective Study Measuring Resident and Faculty Contour Concordance: A Potential Tool for Quantitative Assessment of Residents' Performance in Contouring and Target Delineation in Radiation Oncology Residency

PURPOSE/OBJECTIVE(S)

Accurate target delineation (ie, contouring) is essential for radiation treatment planning and radiotherapy efficacy. As a result, improving the quality of target delineation is an important goal in the education of radiation oncology residents. The purpose of this study was to track the concordance of radiation oncology residents' contours with those of faculty physicians over the course of 1 year to assess for patterns.

MATERIALS/METHODS

Residents in postgraduate year (PGY) levels 2 to 4 were asked to contour target volumes that were then compared to the finalized, faculty physician-approved contours. Concordance between resident and faculty physician contours was determined by calculating the Jaccard concordance index (JCI), ranging from 0, meaning no agreement, to 1, meaning complete agreement. Multivariate mixed-effect models were used to assess the association of JCI to the fixed effect of PGY level and its interactions with cancer type and other baseline characteristics. Post hoc means of JCI were compared between PGY levels after accounting for multiple comparisons using Tukey's method.

RESULTS

In total, 958 structures from 314 patients collected during the 2020-2021 academic year were studied. The mean JCI was 0.77, 0.75, and 0.61 for the PGY-4, PGY-3, and PGY-2 levels, respectively. The JCI score for PGY-2 was found to be lower than those for PGY-3 and PGY-4, respectively (all P < .001). No statistically significant difference of JCI score was found between the PGY-3 and PGY-4 levels. The average JCI score was lowest (0.51) for primary head and/or neck cancers, and it was highest (0.80) for gynecologic cancers.

CONCLUSIONS

Tracking and comparing the concordance of resident contours with faculty physician contours is an intriguing method of assessing resident performance in contouring and target delineation and could potentially serve as a quantitative metric, which is lacking currently, in radiation oncology resident evaluation. However, additional study is necessary before this technique can be incorporated into residency assessments.

Add-on individualizing prediction of nasopharyngeal carcinoma using deep-learning based on MRI: a multicentre, validation study

In nasopharyngeal carcinoma, deep-learning extracted signatures on MR images might be correlated with survival. In this study, we sought to develop an individualizing model using deep-learning MRI signatures and clinical data to predict survival and to estimate the benefit of induction chemotherapy on survivals of patients with nasopharyngeal carcinoma. Two thousand ninety-seven patients from three independent hospitals were identified and randomly assigned. When the deep-learning signatures of the primary tumor and clinically involved gross cervical lymph nodes extracted from MR images were added to the clinical data and TNM staging for the progression-free survival prediction model, the combined model achieved better prediction performance. Its application is among patients deciding on treatment regimens. Under the same conditions, with the increasing MRI signatures, the survival benefits achieved by induction chemotherapy are increased. In nasopharyngeal carcinoma, these prediction models are the first to provide an individualized estimation of survivals and model the benefit of induction chemotherapy on survivals.

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3D-CNN was employed to extract the MRI signatures of nasopharyngeal carcinoma

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The prediction model combined MRI signature, clinical data, TNM staging, and treatment

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The model improved the prediction of progression-free survival and overall survival

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The model can accurately predict individualized survival and decide treatment regimen

Epstein-Barr virus DNA change level combined with tumor volume reduction ratio after inductive chemotherapy as a better prognostic predictor in locally advanced nasopharyngeal carcinoma

BACKGROUND

To explore the prognosis predicting ability of the combined factors, Epstein-Barr virus DNA change level (EBVCL) and tumor volume reduction ratio (TVRR) after inductive chemotherapy (IC), in locally advanced nasopharyngeal carcinoma (LANPC).

METHODS

From 2010 to 2018, 299 LANPC patients were included in this retrospective study. Receiver operating characteristic (ROC) curve analysis was performed to acquire the best critical values. According to the best critical values of EBVCL and TVRR, patients were stratified into low- and high-risk groups. Kaplan-Meier and ROC curve analyses were utilized to verify the prognostic ability of the new predictor (EBVCL+TVRR). The prognostic values among EBVCL+TVRR, EBVCL, TVRR, TNM stage, and the RECIST 1.1 criteria were compared by ROC curve. The primary end points were overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional failure-free survival (LRFFS).

RESULTS

ROC curve analyses of TVRR on three-year survival showed the best critical values of TVRR was 32.72% for OS, 30.21% for PFS and LRFFS, 29.87% for DMFS. The best critical value of EBVCL was 127 copies/ml for OS, and 87.7 copies/ml for PFS, DMFS, and LRFFS. The three-year OS, PFS, DMFS, and LRFFS for low- and high-risk groups were 97.7% versus 78.3% (hazard ratio [HR] = 0.2398; 95% confidence interval [CI]: 0.1277-0.4502; p < 0.0001), 91.1% versus 60.9% (HR = 0.3294; 95% CI: 0.2050-0.5292; p < 0.0001), 94.2% versus 68.7% (HR = 0.2413; 95% CI: 0.1284-0.4535; p < 0.0001) and 97.8% versus 77.9% (HR = 0.3078; 95% CI: 0.1700-0.5573; p = 0.0001), respectively. The maximal area under ROC curve of EBVCL+TVRR, EBVCL, TVRR, TNM stage, and RECIST 1.1 criteria for three-year OS was 0.829, 0.750, 0.711, 0.555, and 0.605, respectively.

CONCLUSION

The new-developed indicator (EBVCL+TVRR) could better predict the LANPC patient's survival after IC compared with TNM stage system or RECIST 1.1 criteria.

Prognostic significance of MRI-based late-course tumor volume in locoregionally advanced nasopharyngeal carcinoma

Background

To validate tumor volume-based imaging markers for predicting local recurrence-free survival (LRFS) in locoregionally advanced nasopharyngeal carcinoma patients, who underwent induction chemotherapy followed by definitive intensity-modulated radiotherapy.

Methods

We enrolled 145 patients with stage III–IVA nasopharyngeal carcinoma in this retrospective study. Pre-treatment tumor volume (V_pre) and late-course volume (LCV) were measured based on the MRIs scanned before treatment and during the first 3 days in the sixth week of radiotherapy, respectively. The volume regression rate (VRR) was calculated according to V_pre and LCV. Receiver operating characteristic (ROC) curves were used to identify the cut-off best separating patient subgroups in assessing the prognostic value of V_pre, LCV and VRR. The Kaplan–Meier method was used for survival analysis. Prognostic analyses were performed using univariate and multivariate COX proportional hazard models.

Results

The LCV was 5.3 ± 0.5 (range 0–42.1) cm³; The VRR was 60.4 ± 2.2% (range 2.9–100.0). The median follow-up period was 36 months (range 6–98 months). The cut-off value of LCV determined by the ROC was 6.8 cm³ for LRFS prediction (sensitivity 68.8%; specificity 79.8%). The combination of LCV and VRR for LRFS prediction (AUC = 0.79, P < 0.001, 95% CI 0.67–0.90), LCV (AUC = 0.74, P = 0.002, 95% CI 0.60–0.88) and V_pre (AUC = 0.71, P = 0.007, 95% CI 0.56–0.85) are better than T category (AUC = 0.64, P = 0.062, 95% CI 0.50–0.79) alone. Patients with LCV ≤ 6.8 cm³ had significantly longer LRFS (P < 0.001), disease-free survival (DFS, P < 0.001) and overall survival (OS, P = 0.005) than those with LCV > 6.8 cm³. Multivariate Cox regression showed LCV was the only independent prognostic factor for local control (HR = 7.80, 95% CI 2.69–22.6, P < 0.001).

Conclusions

LCV is a promising prognostic factor for local control and chemoradiosensitivity in patients with locoregionally advanced NPC. The LCV, and the combination of LCV with VRR are more robust predictors for patient survival than T category.

Does Tumor Volume Have a Prognostic Role in Oropharyngeal Squamous Cell Carcinoma? A Systematic Review and Meta-Analysis

The aim of this study was to assess the prognostic value of tumor volume in oropharyngeal squamous cell carcinoma (OPSCC). The study was performed according to the PRISMA guidelines. A total of 1417 patients with a median age of 59.3 years (IQR 57.5−60) were included. The combined Hazard Ratios (HRs) for overall survival (OS) were 1.02 (95% CI, 0.99−1.05; p = 0.21) for primary tumor volume (pTV) and 1.01 (95% CI, 1.00−1.02; p = 0.15) for nodal tumor volume (nTV). Regarding locoregional control (LRC), the pooled HRs were 1.07 (95% CI, 0.99−1.17; p = 0.10) for pTV and 1.02 (95% CI, 1.01−1.03; p < 0.05) for nTV. Finally, the pooled HRs for disease-free survival (DFS) were 1.01 (95% CI, 1.00−1.03; p < 0.05) for pTV and 1.02 (95% CI, 1.01−1.03; p < 0.05) for nTV. In conclusion, pTV and nTV seem not to behave as reliable prognostic factors in OPSCC.

The Predictive Value of Tumor Volume and Its Change on Short-Term Outcome for Esophageal Squamous Cell Carcinoma Treated With Radiotherapy or Chemoradiotherapy

Objectives

To investigate the tumor volume and its change on short-term outcome in esophageal squamous cell carcinoma (ESCC) patients who underwent definitive radiotherapy or chemoradiotherapy.

Methods and Materials

All data were retrospectively collected from 418 ESCC patients who received radiotherapy or chemoradiotherapy at our institution between 2015 and 2019. Short-term outcome using the treatment response evaluation was assessed according to the RECIST 1.1. The tumor volume change rate (TVCR) was defined as follows: TVCR = {1 - [gross tumor volume (GTV) at shrinking irradiation field planning)]/(GTV at the initial treatment planning)} ×100%. Chi square test was used to compare the clinic characteristics in different TVCR groups, and the difference between initial GTV (GTVi) and shrinking GTV (GTVs) was compared using Wilcoxon's sign rank test. Logistic regression analysis and Spearman correlation was performed.

Results

There was a significant decrease in GTVi compared to GTVs (P < 0.001). In univariate analysis, age, cT-stage, TNM stage, treatment modality, GTVi, and TVCR were associated with short-term outcome (all P < 0.05). In multivariate analysis, gender and TVCR were statistically significant (P = 0.010, <0.001) with short-term outcome, and the combined predictive value of gender and TVCR exceeded that of TVCR (AUC, 0.876 vs 0.855).

Conclusions

TVCR could serve to forecast short-term outcome of radiotherapy or chemoradiotherapy in ESCC. It was of great significance to guide the individualized treatment of ESCC.

Prognostic value of MRI-determined cervical lymph node size in nasopharyngeal carcinoma

Objectives

To investigate the prognostic value of magnetic resonance imaging (MRI)‐determined cervical lymph node (CLN) size in nasopharyngeal carcinoma (NPC).

Methods

We retrospectively reviewed 2066 patients with NPC treated with intensity‐modulated radiotherapy, and randomly divided them into two groups, in a 1:1 ratio. One group was used for training (the training group), and the other one was for internal validation (the validation group). All patients had undergone MRI examination and the maximal axial diameters (MAD) of the axial plane of all positive nodes had been measured and recorded.

Results

Of 683 patients with CLN metastases in the training group (n = 1033), MAD = 4 cm was associated with worse OS (64.7% vs 84.6%, P < .001), DFS (55.9% vs 76.3%, P = .001), and DMFS (67.6% vs 86.1%, P = .001). Multivariate analysis showed that MAD = 4 cm was a significant negative prognostic factor for OS (HR = 2.058; P = .025), DFS (HR = 1.727; P = .049), and DMFS (HR = 2.034; P = .036). When MRI‐determined MAD = 4 cm was classified as N3 in the N classification, the OS, DFS, DMFS, and RRFS survival curves were well separated. The OS, DFS, DMFS, and RRFS concordance indexes were not statistically different between the proposed N staging system and the UICC/AJCC staging system in the training group, or between the training group and the validation group (all P = .05).

Conclusion

MAD = 4 cm on axial MRI slices can be recommended as a prognostic factor in future versions of the UICC/AJCC NPC staging system.

Gross tumour volume comparison in oropharynx carcinomas using different intelligent imaging software. A retrospective analysis

Purpose

To compare gross tumour volume (GTV) in oropharynx carcinomas using different intelligent imaging software and to evaluate which method is more reliable for tumour volume definition in comparison with 3D ProSoma software.

Material and methods

We retrospectively studied 32 patients with histopathologically confirmed oropharynx carcinomas on dual-source computed tomography (CT) (all patients underwent multislice CT examination after applying 75 ml iodinated non-ionic contrast media). One radiologist calculated the tumour volume – manually measuring tumour length (L), width (W), and height (H) – and then calculated the tumour volume using the formula 0.5236 × L × W × H. The other radiologist used the syngo.CT-Liver-Analysis software to calculate the tumour volumes. Both volume measuring methods were compared with the 3D ProSoma software, which is used by radiotherapists to calculate tumour volumes. Graphpad Prism software was used for statistical data.

Results

syngo.CT-Liver-Analysis software for gross tumour volume determination has greater reliability than the standard manual method with Syngo Plaza in comparison with the 3D ProSoma software.

Conclusions

syngo.CT-Liver-Analysis software is a reliable tool for GTV calculation, with a high correlation score, like that of radiotherapeutic 3D ProSoma software.

Prognostic value of nasopharynx tumour volume in local-regional advanced nasopharyngeal carcinoma

Background

To investigate the prognostic value of pretreatment primary gross tumor with (GTVp) and without retropharyngeal lymph nodes (GTVnx) for predicting survival outcomes in patients with local-regional advanced nasopharyngeal carcinoma (NPC) after intensity-modulated radiation therapy (IMRT).

Methods

From Jan 2012 to Dec 2017, 148 patients with local-regional advanced NPC who had undergone definitive radiotherapy were identified. GTVnx volume and retropharyngeal lymph nodes (GTVrLNs) volume were measured based on registration of MRI with contrast-enhanced CT images. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate prognostic analyses was performed by using the Cox proportional hazard model. Receiver operating characteristic (ROC) curves were used to identify the cut-off point and assess the prognostic value for GTVnx, GTVp and GTVrLNs.

Results

The median follow-up time for the entire group was 27 months (ranging 7 to 80 months). The 3-year overall survival (OS) rate was 85%, and the 3-year local failure-free rate (LFFR), distant failure-free rate (DFFR) and disease-free survival (DFS) rates were 93%, 81%, and 73%, respectively. A positive correlation between GTVnx or GTVp volume and T stage was observed (both P<0.001). The 3-year LFFR, OS, and DFS rate, but not for DMFS, in NPC patients with GTVnx ≤42.7 cm³ was significantly better than those with >42.7 cm³ (all P<0.05). Multivariate analysis indicated that GTVnx volume (P=0.041) was the only independent prognostic factor for LFFR, while age and AJCC stage were two independent prognostic factors for OS.

Conclusions

The GTVnx is an independent prognostic factor for local control, while the prognostic value of GTVrLNs is limited. Physicians are recommended to distinguish between GTVnx and retropharyngeal lymph nodes (RLN) involvement when assessing the risk for local recurrence in advanced NPC.

The Role of Post-Neoadjuvant Chemotherapy Tumor Volume for Prognostication and Treatment Guidance in Loco-Regionally Advanced Nasopharyngeal Carcinoma

The value of post-neoadjuvant chemotherapy (NACT) tumor volume for prognostication in loco-regionally advanced nasopharyngeal carcinoma (LA-NPC) is unascertained. Here, we recruited 4109 histologically proven LA-NPC (stage III-IVA) that were treated with radical chemo-intensive-modulated radiotherapy (IMRT). Post-NACT gross primary tumor (GTVp) and lymph node (GTVnd) volumes of each patient were calculated from planning computed tomography (CT). We observed similar linear association between GTVp/GTVnd and overall survival (OS); thresholds of 52 cm³ for GTVp and 12 cm³ for GTVnd were consistent for risk discretization for OS, disease-free survival (DFS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS). Recursive partitioning analysis (RPA) modelling incorporating T-/N-categories and GTVp/GTVnd yielded four T-N-volume (TNV) risk groupings with disparate OS (p < 0.001). TNV risk stratification outperformed GTVp/GTVnd and eighth edition TNM for predicting OS (AUC 0.643 vs. 0.541–0.591; p < 0.001), DFS (0.629 vs. 0.545–0.580; p < 0.001), and DMFS (0.652 vs. 0.522–0.621; p < 0.001). NACT + concurrent chemoradiotherapy (CCRT) over NACT + IMRT was not superior for low- and low–intermediate-risk groupings (p > 0.05 for both), but superior for intermediate- and high-risk groupings in terms of OS (HR 0.68 (95% CI 0.47–0.99) for intermediate risk, 0.73 (0.55–0.97) for high risk; both p < 0.05). Overall, GTVp/GTVnd represent effective indicators for prognostication and decision-making in LA-NPC after NACT.

Combining pretreatment plasma Epstein-Barr virus DNA level and cervical node necrosis improves prognostic stratification in patients with nasopharyngeal carcinoma: A cohort study

This study aimed to evaluate the prognostic value of combining pretreatment Epstein‐Barr virus (EBV) DNA level and cervical node necrosis (CNN) for patients with nasopharyngeal carcinoma (NPC) receiving intensity‐modulated radiotherapy (IMRT). A total of 607 incident nonmetastatic NPC patients treated with IMRT ± chemotherapy were reviewed. Patients were divided into four groups based on EBV DNA level and CNN status. The primary endpoint was progression‐free survival (PFS). Kaplan‐Meier curves with log‐rank test were applied to compare survival outcomes and the Cox proportional model was used to identify independent prognostic factors. Pretreatment EBV DNA level and CNN status were independent prognostic factors. Patients in the low‐level EBV DNA group or non‐CNN group had significantly better 5‐year PFS. Multivariate analyses demonstrated that CNN was an independent prognostic factor for overall survival (OS) (HR = 1.927, 95% CI: 1.129‐3.290, P = .016), PFS (HR = 1.492, 95% CI: 1.005‐2.214, P = .047), distant metastasis‐free survival (DMFS) (HR = 1.661, 95% CI: 1.044‐2.644, P = .032), but not locoregional relapse‐free survival. EBV DNA levels correlated significantly with CNN with a correlation coefficient of .324 (P < .001). Compared with low‐level EBV DNA and non‐CNN grouping, high‐level EBV DNA and CNN grouping had poor PFS. The combined classification was an independent prognostic factor for OS (P < .001), PFS (P = .001), and DMFS (P = .018). Pretreatment plasma EBV DNA level and CNN status both closely correlated with prognosis of NPC patients in the IMRT era. Combined EBV DNA level and CNN status improves risk stratification and prognostic value.

Radiomics Model to Predict Early Progression of Nonmetastatic Nasopharyngeal Carcinoma after Intensity Modulation Radiation Therapy: A Multicenter Study

Purpose

To examine the prognostic value of a machine learning model trained with pretreatment MRI radiomic features in the assessment of patients with nonmetastatic nasopharyngeal carcinoma (NPC) who are at risk for 3-year disease progression after intensity-modulated radiation therapy and to explain the radiomics features in the model.

Materials and Methods

A total of 277 patients with nonmetastatic NPC admitted between March 2008 and December 2014 at two imaging centers were retrospectively reviewed. Patients were allocated to a discovery or validation cohort based on where they underwent MRI (discovery cohort, n = 217; validation cohort, n = 60). A total of 525 radiomics features extracted from contrast material-enhanced T1- or T2-weighted MRI studies and five clinical features were subjected to radiomic machine learning modeling to predict 3-year disease progression. Feature selection was performed by analyzing robustness to resampling, reproducibility between observers, and redundancy. Features for the final model were selected with Kaplan-Meier analysis and the log-rank test. A support vector machine was used as the classifier for the model. To interpret the pattern learned from the model, Shapley additive explanations (SHAP) was applied.

Results

The final model yielded an area under the receiver operating characteristic curve of 0.80 in both the discovery (95% bootstrap confidence interval: 0.80, 0.81) and independent validation (95% bootstrap confidence interval: 0.73, 0.89) cohorts. Analysis with SHAP revealed that tumor shape sphericity, first-order mean absolute deviation, T stage, and overall stage were important factors in 3-year disease progression.

Conclusion

These results add to the growing evidence of the role of radiomics in the assessment of NPC. By using explanatory techniques, such as SHAP, the complex interaction of features learned by the model may be understood.© RSNA, 2019Supplemental material is available for this article.

Evaluation of Volume of Nasopharyngeal Cancers by the Cavalieri Principle

Prediction of tumor volume using the Cavalieri method may be helpful in management of therapy and evaluation of treatment results. The aim of this study was to adapt the Cavalieri stereological method to magnetic resonance imaging for determining volume of nasopharyngeal cancers and assess changes after treatment using the Cavalieri method. Serial MRI images in the sagittal plane were obtained from a total of 33 patients with nasopharyngeal carcinomas (11 with stage T2, 11 with stage T3, and 11 with stage T4 lesions). The images were analyzed retrospectively before and two months following the cessation of radiochemotherapy for comparison. Average tumor volumes before and after treatment in patients with stage T2 were 21. 5±10.5 cm3 and 2.82±3.43 cm³, respectively (p=0.000). The respective figures were 35.1±19.0 cm3 and 6.27±7.82 cm³ (p=0.000) for stage T3 cases, and 62.8±27.8 cm3 and 11. 6±11.9 cm3 (p=0.000) for stage T4. Post-treatment tumor volumes were statistically reduced when compared to pre-treatment volumes in all stages.

Combination of Tumor Volume and Epstein-Barr Virus DNA Improved Prognostic Stratification of Stage II Nasopharyngeal Carcinoma in the Intensity Modulated Radiotherapy Era: A Large-Scale Cohort Study

PURPOSE

Little is known about combination of the circulating Epstein-Barr viral (EBV) DNA and tumor volume in prognosis of stage II nasopharyngeal carcinoma (NPC) patients in the intensity modulated radiotherapy (IMRT) era. We conducted this cohort study to evaluate the prognostic values of combining these two factors.

MATERIALS AND METHODS

By Kaplan-Meier, we compare the differences of survival curves between 385 patients with different EBV DNA or tumor volume levels, or with the combination of two biomarkers mentioned above.

RESULTS

Gross tumor volume of cervical lymph nodes (GTVnd, p < 0.001) and total tumor volume (GTVtotal, p < 0.001) were both closely related to pretreatment EBV DNA, while gross tumor volume of nasopharynx (GTVnx, p=0.047) was weakly related to EBV DNA. EBV DNA was significantly correlated with progress-free survival (PFS, p=0.005), locoregional-free survival (LRFS, p=0.039), and distant metastasis-free survival (DMFS, p=0.017), while GTVtotal, regardless of GTVnx and GTVnd, had a significant correlation with PFS and LRFS. The p-values of GTVtotal for PFS and LRFS were 0.008 and 0.001, respectively. According to GTVtotal and pretreatment EBV DNA level, patients were divided into a low-risk group (EBV DNA 0 copy/mL, GTVtotal < 30 cm3; EBV DNA 0 copy/mL, GTVtotal ≥ 30 cm3; or EBV DNA > 0 copy/mL, GTVtotal < 30 cm3) and a high-risk group (EBV DNA > 0 copy/mL, GTVtotal ≥ 30 cm3). When patients in the low-risk group were compared with those in the high-risk group, 3-year PFS (p=0.003), LRFS (p=0.010), and DMFS (p=0.031) rates were statistically significant.

CONCLUSION

Pretreatment plasma EBV DNA and tumor volume were both closely correlated with prognosis of stage II NPC patients in the IMRT era. Combination of EBV DNA and tumor volume can refine prognosis and indicate for clinical therapy.

Regionally Advanced Nasopharyngeal Carcinoma: Long-Term Outcome after Sequential Chemotherapy and Radiotherapy

Aims and background

To evaluate the long-term clinical outcome of 61 patients with regionally advanced nasopharyngeal carcinoma treated with sequential chemotherapy and radiotherapy within a phase II trial.

Methods

The trial evaluated a combined modality regimen including 3 cycles of induction polychemotherapy (epirubicin 70 mg/m2 d1, and cisplatin 100 mg/m2 d1, both recycled every 3 weeks) followed by definitive radiotherapy to the primary site (64–70 Gy) and the neck (50–70 Gy). Patients included in the trial had pathologically confirmed nasopharyngeal carcinoma; stage (UICC 1987) T-any, N2-3, M0; ECOG performance status 0–1. Sixty-one patients were enrolled between 1990 and 1996; stage according to UICC 1997 was IIb in 8%, III in 36% and IV in 56% of the patients; histology was WHO type 1–2 in 11% and WHO type 3 in 89% of cases. Minimum follow-up of 33 surviving patients is 5.2 years.

Results

Clinical failure has been observed in 30 patients (49%): initial failure, observed within the third year of follow-up in all but one case, was local alone in 6 (20%), regional alone in 10 (33%), local and regional in 1 (3%), regional and distant in 1 (3%), and distant alone in 12 patients (40%). Seven patients received salvage surgery to the neck, 2 of them still disease-free at 10 and 11 years from salvage surgery; 4 patients with an isolated local relapse were re-irradiated, and one of them was alive and well at 6.5 years from salvage radiation. At 5-year local control, regional control and distant metastasis-free rates were 83%, 74% and 73%, respectively; overall and disease-free survival were 64% and 51%. Late effects of initial treatment, as evaluated in 30 patients surviving 5 years without relapse, were generally acceptable, but some degree of xerostomia, dental damage, trismus and hearing loss were reported by a significant proportion of patients (respectively 100%, 88%, 76% and 86%).

Conclusions

In our experience, long-term clinical cure of regionally advanced nasopharyngeal carcinoma was obtained in 51% of cases treated with chemotherapy and radiotherapy. Salvage treatments (neck surgery, local re-irradiation) are worthy, as they increase the cure rate by approximately 10%, raising 5-year survival to over 60%. Late effects are significant, calling for refinements in radiation technique, better integration with chemotherapy to possibly decrease the need for higher radiation dose, and/or use of effective radioprotectants.

Prognostic values of the integrated model incorporating the volume of metastatic regional cervical lymph node and pretreatment serum Epstein-Barr virus DNA copy number in predicting distant metastasis in patients with N1 nasopharyngeal carcinoma

Background

According to the 7th edition of the American Joint Committee on Cancer (AJCC) staging system, over 50% of patients with nasopharyngeal carcinoma (NPC) have N1 disease at initial diagnosis. However, patients with N1 NPC are relatively under-researched, and the metastasis risk of this group is not well-stratified. This study aimed to evaluate the prognostic values of gross tumor volume of metastatic regional lymph node (GTVnd) and pretreatment serum copy number of Epstein–Barr virus (EBV) DNA in predicting distant metastasis of patients with N1 NPC, and to develop an integrated prognostic model that incorporates GTVnd and EBV DNA copy number for this group of patients.

Methods

The medical records of 787 newly diagnosed patients with nonmetastatic, histologically proven N1 NPC who were treated at Sun Yat-sen University Cancer Center between November 2009 and February 2012 were analyzed. Computed tomography-derived GTVnd was measured using the summation-of-area technique. Blood samples were collected before treatment to quantify plasma EBV DNA. The receiver operating characteristic (ROC) curve analysis was used to evaluate the cut-off point for GTVnd, and the area under the ROC curve was used to assess the predicted validity of GTVnd. The survival rates were assessed by Kaplan–Meier analysis, and the survival curves were compared using a log-rank test. Multivariate analysis was conducted using the Cox proportional hazard regression model.

Results

The 5-year distant metastasis-free survival (DMFS) rates for patients with GTVnd > 18.9 vs. ≤ 18.9 mL were 82.2% vs. 93.2% (P < 0.001), and for patients with EBV DNA copy number > 4000 vs. ≤ 4000 copies/mL were 83.5% vs. 93.9% (P < 0.001). After adjusting for GTVnd, EBV DNA copy number, and T category in the Cox regression model, both GTVnd > 18.9 mL and EBV DNA copy number > 4000 copies/mL were significantly associated with poor prognosis (both P < 0.05). According to combination of GTVnd and EBV DNA copy number, all patients were divided into low-, moderate-, and high-risk groups, with the 5-year DMFS rates of 96.1, 87.4, and 73.8%, respectively (P < 0.001). Multivariate analysis confirmed the prognostic value of this model for distant metastatic risk stratification (hazard ratio [HR], 4.17; 95% confidence interval [CI] 2.34–7.59; P < 0.001).

Conclusions

GTVnd and serum EBV DNA copy number are independent prognostic factors for predicting distant metastasis in NPC patients with N1 disease. The prognostic model incorporating GTVnd and EBV DNA copy number may improve metastatic risk stratification for this group of patients.

Prognostic value of total tumor volume in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Background

Few studies have evaluated the prognostic value of total tumor volume (TTV), which reflects both the primary tumor volume and nodal tumor volume, in NPC. Furthermore, the relationship between TTV and survival remains unknown. The purpose of this study was to evaluate the prognostic value of TTV in patients with NPC treated with intensity-modulated radiation therapy (IMRT).

Methods

TTV was retrospectively assessed in 455 patients with newly diagnosed, non-metastatic NPC. All patients were treated using IMRT; 91.1% (288/316) of patients with stage III-IVb also received cisplatin-based chemotherapy. Receiver operating characteristic (ROC) curves were used to identify the optimal TTV cut-off point and examine the prognostic value of combined TTV with current clinical stage.

Results

Mean TTV was 11.1 cm³ (range, 0.3–27.9 cm³) in stage I, 22.5 cm³ (1.3–92.4 cm³) in stage II, 40.6 cm³ in stage III (3.2–129.2 cm³), and 77.5 cm³ in stage IVa-b (7.1–284.1 cm³). For all patients, the 4-year estimated FFS, OS, DMFS, and LRRFS rates for patients with a TTV ≤ 28 vs. > 28 cm³ were 93 vs. 71.4% (P < 0.001), 95.1 vs. 75.4% (P < 0.001), 94.5 vs. 79.4% (P < 0.001), and 96.2 vs. 88% (P = 0.001). TTV was an independent prognostic factor for FFS, OS, DMFS and LRRFS in all patients. In stage III-IVb, 4-year estimated FFS, OS, DMFS, and LRRFS for a TTV ≤28 vs. >28 cm³ were 88.9 vs. 70.5% (P = 0.001), 96.2 vs. 72.7% (P < 0.001), 91.2 vs. 78.3% (P = 0.008), and 93.8 vs. 87.6% (P = 0.063). TTV was an independent prognostic factor for FFS, OS and DMFS in stage III-IVb. Receiver operating characteristic (ROC) curve analysis curves revealed adding TTV to clinical stage had superior prognostic value for treatment failure compared to clinical stage alone (P = 0.016).

Conclusions

TTV is an important prognosticator for treatment outcome and significantly improves the prognostic value of the current staging system for patients with NPC treated with IMRT.

Prognostic value of cervical nodal tumor volume in nasopharyngeal carcinoma: Analysis of 1230 patients with positive cervical nodal metastasis

Purpose

To investigate the variability and prognostic value of nodal tumor volume (NTV) in nasopharyngeal carcinoma (NPC).

Methods and materials

Data on 1230 patients with newly diagnosed stage T1-4N1-3M0 NPC treated with definitive radiation therapy with or without chemotherapy at a single cancer center were reviewed. NTV was determined from dose volume histogram (DVH) data. X-tile analysis was applied to identify the optimal cut-off points for the NTV with respect to regional recurrence-free survival (RRFS). Correlations between the TNM classification system, NTV and RRFS were assessed using a Cox regression model. Cross-validation based on receiver operating characteristic (ROC) curve analysis was applied to compare the prognostic predictive validity of NTV and N categories.

Results

Within a median follow-up of 49.9 (range, 1.27–76.40) months, 61/1230 (5%) patients developed regional recurrence and 154 (12.5%) developed distant metastasis. NTV values of 7.2 cc and 35.7 cc were identified as the optimal cut-off points. Patients with larger NTV had poorer prognosis. Compared with the N category, NTV was better at determining RRFS for patients with NPC. Hazard ratios increased with NTV, ranging from 1.86 (95% confidence interval [95% CI], 0.92–3.78) for NTV between 7.2 cc to 35.7 cc, and 3.67 (95% CI, 1.58–8.50) for NTV > 35.7 cc. With both NTV and N category in the same Cox regression model, only NTV remained statistically significant in the RRFS of NPC. The validation results with ROC curves also revealed that, NTV was superior to N category for predicting RRFS with significantly larger area under the ROC curve.

Conclusions

NTV offers important prognostic value for treatment outcomes in NPC, especially regional control. Volumetric analysis of nodal involvement may assist selection of patients with poor prognosis.

Prediction of distant metastases from nasopharyngeal carcinoma: Improved diagnostic performance of MRI using nodal volume in N1 and N2 stage disease

PURPOSE

To determine if the magnetic resonance imaging (MRI) of the head and neck can predict distant metastases (DM) from nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

MRI examinations of 763 NPC patients were assessed for primary tumour stage (T), nodal stage (N), primary tumour volume (PTV) and total nodal volume (NV). The association between MRI and clinical parameters were examined in DM+ and DM- patients using logistic regression and for distant metastases free survival (DMFS) using cox regression. Optimum thresholds were assessed by receiver-operating characteristics analysis, and positive predictive value (PPV) and odds ratio (OR) calculated.

RESULTS

Distant metastases were present in 181/763 NPC patients (23.7%). Higher N stage and NV were the independent predictors of DM (p<0.001 and 0.018 respectively) and poor DMFS (p=0.001 and 0.030 respectively). Addition of NV (threshold≥32.8cm³) to the N stage improved the PPVs and ORs for DM in stage N1 (from 18.9% to 31.8% and 5.613 to 11.133 respectively) and stage N2 (from 40.4% to 60.8% and 16.189 to 36.979 respectively) but not in stage N3 (68.3% to 68.6% and 51.385 to 52.052 respectively).

CONCLUSION

MRI N stage and NV were independent predictors of DM and DMFS. The addition of NV in NPC patients with bulky N1 and N2 disease improved the ability of MRI to predict DM.

Radiotherapy with neoadjuvant chemotherapy versus concurrent chemoradiotherapy for ascending-type nasopharyngeal carcinoma: a retrospective comparison of toxicity and prognosis

Background

In the era of intensity-modulated radiotherapy (IMRT), the role of neoadjuvant chemotherapy (NACT) in treating ascending-type nasopharyngeal carcinoma (NPC) is under-evaluated. This study was to compare the efficacy of NACT followed by IMRT (NACT + RT) with the efficacy of concurrent chemoradiotherapy (CCRT) on ascending-type NPC.

Methods

Clinical data of 214 patients with ascending-type NPC treated with NACT + RT or CCRT between December 2009 and July 2011 were analyzed. Of the 214 patients, 98 were treated with NACT followed by IMRT, and 116 were treated with CCRT. The survival rates were assessed using Kaplan–Meier analysis, and the survival curves were compared using a log-rank test.

Results

The 4-year overall survival, locoregional failure-free survival, distant failure-free survival, and failure-free survival rates were not significantly different between the two groups (all P > 0.05). However, patients in the CCRT group exhibited more severe acute adverse events than did patients in the NACT + RT group during radiotherapy, including leukopenia (30.2% vs. 15.3%, P = 0.016), neutropenia (25.9% vs. 11.2%, P = 0.011), and mucositis (57.8% vs. 40.8%, P = 0.028). After radiotherapy, patients in the CCRT group exhibited significantly higher rates of xerostomia (21.6% vs. 10.2%, P = 0.041) and hearing loss (17.2% vs. 6.1%, P = 0.023).

Conclusions

The treatment outcomes of the NACT + RT and CCRT groups were similar; however, CCRT led to higher rates of acute and late toxicities. NACT + RT may therefore be a better treatment strategy for ascending-type NPC.

Lymph node standardized uptake values at pre-treatment 18F-fluorodeoxyglucose positron emission tomography as a valuable prognostic factor for distant metastasis in nasopharyngeal carcinoma

Objective:

The aim of the present study was to evaluate prognostic values of pre-treatment fluorine-18 fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) parameters for predicting the distant metastasis (DM) of nasopharyngeal cancer.

Methods:

73 patients diagnosed with nasopharyngeal cancer with regional lymph node (LN) involvement, who underwent pre-treatment ¹⁸F-FDG PET evaluation between January 2005 and December 2012, were retrospectively reviewed. We assessed the ¹⁸F-FDG PET parameters of the primary tumours (T–) and regional LNs (N–). For patients with bilateral retropharyngeal, bilateral neck and/or supraclavicular LN involvement, we also assessed the ¹⁸F-FDG PET parameters of the farthest LN station [N(f)–]. The following ¹⁸F-FDG PET parameters were evaluated: maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), peak standardized uptake value (SUV_peak), metabolic tumour volumes (MTVs) (MTV₃₀–MTV₇₀, which were calculated as the tumour volume with 30%, 40%, 50%, 60% and 70% of the SUV_max as the threshold, respectively) and total lesion glycolysis (TLG) (TLG₃₀–TLG₇₀, which were determined by the product of each MTV and the corresponding SUV_mean within that MTV). Distant metastasis-free survival (DMFS) rates were estimated from the date of the start of radiotherapy to the date of DM or last follow-up by the Kaplan–Meier method. Univariate and multivariate analyses were performed to identify prognostic factors for DMFS. The median follow-up period was 53 months (range 12–110 months).

Results:

Most patients (95%) received concurrent chemoradiotherapy. The major failure pattern was DM (15 of all patients, 21%) and the 5-year DMFS was 79%. In univariate analysis, the T–SUV_max, T–SUV_mean, T–SUV_peak, N–SUV_max, N–SUV_peak, N(f)–SUV_max and N(f)–SUV_peak were significant prognostic factors for DMFS. In multivariate analysis, the T–SUV_max, T–SUV_peak, N(f)–SUV_max and N(f)–SUV_peak were significant prognostic factors for DMFS. Of these parameters, the N(f)–SUV_max (hazard ratio = 6.524; p = 0.001) and N(f)–SUV_peak (hazard ratio = 5.399; p = 0.001) were the strongest prognostic factors for DMFS.

Conclusion:

In patients with nasopharyngeal cancer with LN involvement, the standardized uptake value parameter of the farthest LN station seems to be an important ¹⁸F-FDG PET parameter for predicting DM. Further studies are needed to validate its clinical significance.

Advances in knowledge:

We found that pre-treatment ¹⁸F-FDG PET parameters of primary tumours and regional LNs (the SUV_max and SUV_peak of the primary tumour and the farthest LN station) were significant prognostic factors for DMFS in patients with nasopharyngeal carcinoma with LN involvement.

Modelling tumour volume variations in head and neck cancer: contribution of magnetic resonance imaging for patients undergoing induction chemotherapy

Primary tumour volume evaluation has predictive value for estimating survival outcomes. Using volumetric data acquired by MRI in patients undergoing induction chemotherapy (IC) these outcomes were estimated before the radiotherapy course in head and neck cancer (HNC) patients. MRI performed before and after IC in 36 locally advanced HNC patients were analysed to measure primary tumour volume. The two volumes were correlated using the linear-log ratio (LLR) between the volume in the first MRI and the volume in the second. Cox's proportional hazards models (CPHM) were defined for loco-regional control (LRC), disease-free survival (DFS) and overall survival (OS). Strict evaluation of the influence of volume delineation uncertainties on prediction of final outcomes has been defined. LLR showed good predictive value for all survival outcomes in CPHM. Predictive models for LRC and DFS at 24 months showed optimal discrimination and prediction capability. Evaluation of primary tumour volume variations in HNC after IC provides an example of modelling that can be easily used even for other adaptive treatment approaches. A complete assessment of uncertainties in covariates required for running models is a prerequisite to create reliable clinically models.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy

Background

Gross target volume of primary tumor (GTV-P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma (NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity-modulated radiotherapy (IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to find a suitable cut-off value of GTV-P for prognosis prediction.

Methods

Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver operating characteristic (ROC) curves were used to identify the cut-off values of GTV-P for the prediction of different endpoints [overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS)] and to test the prognostic value of GTV-P when compared with that of the American Joint Committee on Cancer T staging system.

Results

The 358 patients with locally advanced NPC were divided into two groups by the cut-off value of GTV-P as determined using ROC curves: 219 (61.2%) patients with GTV-P ≤46.4 mL and 139 (38.8%) with GTV-P >46.4 mL. The 3-year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV-P ≤46.4 mL than in those with GTV-P > 46.4 mL (all P < 0.05). Multivariate analysis indicated that GTV-P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve verified that the predictive ability of GTV-P was superior to that of T category (P < 0.001). The cut-off values of GTV-P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.

Conclusion

In patients with locally advanced NPC, GTV-P >46.4 mL is an independent unfavorable prognostic indicator for survival after IMRT, with a prognostic value superior to that of T category.

Prognostic efficacy of combining tumor volume with Epstein-Barr virus DNA in patients treated with intensity-modulated radiotherapy for nasopharyngeal carcinoma

OBJECTIVES

To evaluate the prognostic effect of combining tumor volume with pre-treatment plasma Epstein-Barr virus DNA (EBV DNA) in patients treated with intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

A total of 180 consecutive NPC patients enrolled in this observational, prospective study and underwent IMRT. Tumor volume was delineated with IMRT planning system and plasma EBV DNA level was quantified by polymerized chain-reaction assay. The effects of tumor volume and EBV DNA level, either alone or in combination, on 5-year overall survival (OS) were cross-compared.

RESULTS

The 5-year OS in patients with gross tumor volume of nasopharynx (GTVnx)⩽20cc and >20cc was significantly different (P=0.001). The 5-year OS in patients with EBV DNA <6800copies/mL and ⩾6800copies/mL was also significantly different (P<0.001). Based on the combination of GTVnx with EBV DNA, the 5-year OS in different subgroups was: low-risk (100%), intermediate-risk (87.8%, 95% CI: 70.6-95.2%) and high-risk (61.3%, 95% CI: 47.9-72.2%). Patients with small tumor volume and high EBV DNA level had a worse prognosis than those with large tumor and low EBV DNA level. Patients with low EBV DNA levels, and either small or large tumor volumes, had favorable prognosis. According to small or large tumor volume, patients with high EBV DNA level were divided into intermediaterisk and high-risk subgroups.

CONCLUSION

Combining tumor volume with pre-treatment plasma EBV DNA level altered survival-risk definition for subgroups of NPC patients and this combination, more than individual factors alone, improved the accuracy of prognostic evaluation.

Diffusion-Weighted Imaging of Nasopharyngeal Carcinoma: Can Pretreatment DWI Predict Local Failure Based on Long-Term Outcome?

BACKGROUND AND PURPOSE

Pretreatment prediction of patients with nasopharyngeal carcinoma who will fail conventional treatment would potentially allow these patients to undergo more intensive treatment or closer posttreatment monitoring. The aim of the study was to determine the ability of pretreatment DWI to predict local failure in patients with nasopharyngeal carcinoma based on long-term clinical outcome.

MATERIALS AND METHODS

One hundred fifty-eight patients with pretreatment DWI underwent analysis of the primary tumor to obtain the ADC mean, ADC skewness, ADC kurtosis, volume, and T-stage. Univariate and multivariate analyses using logistic regression were performed to compare the ADC parameters, volume, T-stage, and patient age in primary tumors with local failure and those with local control, by using a minimum of 5-year follow-up to confirm local control.

RESULTS

Local control was achieved in 131/158 (83%) patients (range, 60.3-117.7 months) and local failure occurred in 27/158 (17%) patients (range, 5.2-79.8 months). Compared with tumors with local control, those with local failure showed a significantly lower ADC skewness (ADC values with the greatest frequencies were shifted away from the lower ADC range) (P = .006) and lower ADC kurtosis (curve peak broader) (P = .024). The ADC skewness remained significant on multivariate analysis (P = .044). There was a trend toward higher tumor volumes in local failure, but the volume, together with T-stage and ADC mean, were not significantly different between the 2 groups.

CONCLUSIONS

Pretreatment DWI of primary tumors found that the skewness of the ADC distribution curve was a predictor of local failure in patients with nasopharyngeal carcinoma, based on long-term clinical outcome.

Prognostic Model of Death and Distant Metastasis for Nasopharyngeal Carcinoma Patients Receiving 3DCRT/IMRT in Nonendemic Area of China

Few studies were conducted to explore the prognostic factors for nonendemic nasopharyngeal carcinoma (NPC) in the era of 3-dimensional conformal radiation therapy (3DCRT)/intensity-modulated radiation therapy (IMRT). The aim of this study was to evaluate the potential prognostic factors for nonendemic NPC.Between January 2004 and December 2011, a total of 393 nonendemic NPC patients receiving 3DCRT/IMRT were reviewed according to the inclusion and exclusion criteria. The prognostic factors we analyzed included age, T stage, N stage, lymph node diameter, primary tumor volume, WHO histology types, and cranial nerve related symptoms. All patients were staged according to the 7th edition of the American Joint Committee on Cancer (AJCC) system. The factors found to be associated with the endpoints by univariate analyses were then entered into multivariate Cox proportional hazards regression analysis.The median follow-up time was 61.4 months (range: 4-130 months). The 5-year local recurrent-free survival (LRFS), nodal relapse-free survival (NRFS), distant metastasis free survival (DMFS), and disease-specific survival (DSS) for all patients were 89.3%, 96.4%, 73.5%, and 74.3%, respectively. Multivariate analysis indicated that N stage (N2-3), WHO pathologic type II, and primary tumor volume (>23 mL) were 3 independent prognostic factors for DSS and DMFS. According to the number of prognostic factors, patients were divided into 3 risk groups: low-risk group (patients without any risk factors); intermediate-risk group (patients with only 1 risk factor); and high-risk group (patients with more than 2 risk factors). The 5-year DSS for low, intermediate, and high-risk groups were 91.5%, 75.2%, and 49.3%, respectively (P < 0.001). The 5-year DMFS for low, intermediate, and high-risk groups were 89.4%, 77.9%, and 49.4%, respectively (P < 0.001).Advanced N stage (N2-3), larger tumor volume (>23 mL), and histological WHO type II are independently prognostic factors for nonendemic NPC patients in China.

Tumor Volumes and Prognosis in Laryngeal Cancer

Tumor staging systems for laryngeal cancer (LC) have been developed to assist in estimating prognosis after treatment and comparing treatment results across institutions. While the laryngeal TNM system has been shown to have prognostic information, varying cure rates in the literature have suggested concern about the accuracy and effectiveness of the T-classification in particular. To test the hypothesis that tumor volumes are more useful than T classification, we conducted a retrospective review of 78 patients with laryngeal cancer treated with radiation therapy at our institution. Using multivariable analysis, we demonstrate the significant prognostic value of anatomic volumes in patients with previously untreated laryngeal cancer. In this cohort, primary tumor volume (GTV_P), composite nodal volumes (GTV_N) and composite total volume (GTV_P + GTV_N = GTV_C) had prognostic value in both univariate and multivariate cox model analysis. Interestingly, when anatomic volumes were measured from CT scans after a single cycle of induction chemotherapy, all significant prognosticating value for measured anatomic volumes was lost. Given the literature findings and the results of this study, the authors advocate the use of tumor anatomic volumes calculated from pretreatment scans to supplement the TNM staging system in subjects with untreated laryngeal cancer. The study found that tumor volume assessment after induction chemotherapy is not of prognostic significance.

Tumor Volume Reduction Rate during Adaptive Radiation Therapy as a Prognosticator for Nasopharyngeal Cancer

Purpose

The purpose of this study is to evaluate the prognostic significance of the tumor volume reduction rate (TVRR) measured during adaptive definitive radiation therapy (RT) for nasopharyngeal cancer (NPC).

Materials and Methods

We reviewed the RT records of 159 NPC patients treated with definitive RT with or without concurrent chemotherapy between January 2006 and February 2013. Adaptive re-planning was performed in all patients at the third week of RT. The pre- and mid-RT gross tumor volumes (GTVs) of the primary tumor and the metastatic lymph nodes were measured and analyzed for prognostic implications.

Results

After a median follow-up period of 41.5 months (range, 11.2 to 91.8 months) for survivors, there were 43 treatment failures. The overall survival and progression-free survival (PFS) rates at 5 years were 89.6% and 69.7%, respectively. The mean pre-RT GTV, mid-RT GTV, and TVRR were 45.9 cm³ (range, 1.5 to 185.3 cm³), 26.7 cm³ (1.0 to 113.8 cm³), and –41.9% (range, –87% to 78%), respectively. Patients without recurrence had higher TVRR than those with recurrence (44.3% in the no recurrence group vs. 34.0% in the recurrence group, p=0.004), and those with TVRR > 35% achieved a significantly higher rate of PFS at 5 years (79.2% in TVRR > 35% vs. 53.2% in TVRR ≤ 35%; p < 0.001). In multivariate analysis, TVRR was a significant factor affecting PFS (hazard ratio, 2.877; 95% confidence interval, 1.555 to 5.326; p=0.001).

Conclusion

TVRR proved to be a significant prognostic factor in NPC patients treated with definitive RT, and could be used as a potential indicator for early therapeutic modification during the RT course.

Risk factors and prediction-score model for distant metastasis in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

The objective of this study is to identify the risk factors and construct a prediction-score model for distant metastasis (DM) in nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT). A total of 520 nonmetastatic NPC patients were analysed retrospectively. The independent risk factors for DM were tested by multivariate Cox regression analysis. The prediction-score model was established according to the regression coefficient. The median follow-up was 88.4 months. The 5-year DM rate was 15.1%. N2-3, primary tumour volume of nasopharynx (GTVnx) >24.56 cm(3), haemoglobin change after treatment (ΔHGB) >25.8 g/L, albumin-globulin ratio (AGR) ≤1.34, pretreatment neutrophil-lymphocyte ratio (NLR) >2.81 and pretreatment serum lactate dehydrogenase (LDH) >245 U/L were significantly adverse independent predictive factors for DM. Three subgroups were defined based on the prediction-score model: low risk (0-2), intermediate risk (3-4) and high risk (5-8). The 5-year DM rates were 4.6, 21.8 and 50.8%, respectively (P < 0.001). The areas under the curve for DM in the prediction-score model and the UICC/AJCC staging system seventh edition were 0.748 and 0.627, respectively (P < 0.001). The scoring model is useful in evaluating the risk of DM in IMRT-treated NPC patients and guiding future therapeutic trials. Further prospective study is needed.

Is maximum primary tumor diameter still a prognostic factor in patients with nasopharyngeal carcinoma treated using intensity-modulated radiotherapy?

BACKGROUND

Intensity-modulated radiation therapy (IMRT) has represented a technical milestone that has facilitated the clinical implementation. The purpose of this study was to evaluate the prognostic value of maximum primary tumor diameter (MPTD) in patients with nasopharyngeal carcinoma (NPC) treated using IMRT.

METHODS

Five-hundred and sixty-six patients with non-metastatic, histologically-confirmed NPC were retrospectively reviewed. MPTD was measured using magnetic resonance imaging (MRI). All patients were treated using IMRT; 87.5% (456/521) of patients with Stage T3-T4/N1-N3 disease also received cisplatin-based chemotherapy. Receiver operating characteristic (ROC) curves were used to identify the optimal MPTD cut-off point and examine the prognostic value of combining MPTD with the current T classification criteria.

RESULTS

Median follow-up for all patients was 36 months (range, 1-52 months). The 3-year overall survival (OS), failure-free survival (FFS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS) rates for patients with a MPTD ≤41 vs. >41 mm were 96.1% vs. 85.4%, 93.7% vs. 74.7%, 96.1% vs. 79.7%, and 98.1% vs. 92.9%, respectively (all P < 0.05). In multivariate analysis, MPTD was an independent prognostic factor for OS, FFS, DMFS and LRFS in all patients (all P < 0.05). Among stage T3-T4 patients, the 3-year OS, FFS, DMFS, and LRFS rates for patients with a MPTD ≤41 vs. >41 mm were 96.9% vs. 84.5%, 95.4% vs. 73.5%, 96.1% vs. 79.2%, and 99.3% vs. 92.6%, respectively (all P < 0.05). In multivariate analysis, MPTD was also an independent prognostic factor for OS, FFS and DMFS in stage T3-T4 patients (all P < 0.05), and the difference in LRFS was almost statistically significant (P = 0.05). ROC curves verified that inclusion of MPTD improved the predictive value of the current T classification criteria (P < 0.001).

CONCLUSIONS

MPTD was an independent prognostic factor in patients with NPC treated using IMRT, and significantly improved the prognostic value of the current T classification criteria for NPC.

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.

Should all nasopharyngeal carcinoma with masticator space involvement be staged as T4?

INTRODUCTION

The prognostic significance of the involvement of anatomical masticator space (MS) in nasopharyngeal carcinoma (NPC) was retrospectively reviewed.

MATERIAL AND METHODS

1104 Patients with non-metastatic NPC treated with radical radiotherapy between 1998 and 2010 were re-staged according to the 7th edition of the American Joint Committee on Cancer (AJCC) staging system; tumors with medial pterygoid muscle (MP) and/or lateral pterygoid muscle (LP) involvement but did not fulfill the criteria for T3 or T4 were staged as TX. The tumor volume data, dosimetric data and survival endpoints of different T stage diseases were analyzed and compared to study the significance of MS involvement.

RESULTS

The overall MS involvement rate was 61.0%. The median volumes of the primary gross tumor volume were 9.6ml, 15.2ml, 19.9ml, 32.6ml and 77.3ml for T1, T2, TX, T3 and T4, respectively (p<0.001). T1, T2 and TX tumors received higher minimum dose to the gross tumor volume and planning target volume than T3 and T4. Multivariate analysis showed that age, gender, T-/N-classification and the use of chemotherapy were significant prognostic factors for various survival end-points. Patients with TX disease had similar survival rates as with T1-T2; and had a significantly better 5-year overall survival rate (86.6% vs. 76.6%; p=0.013) and a trend of higher 5-year distant failure-free survival rate (91.5% vs. 81.3%; p=0.09) than patients with T3 disease.

CONCLUSION

NPC with the involvement of MP and/or LP alone should be classified as T2 disease.

MR imaging prediction of local control of nasopharyngeal carcinoma treated with radiation therapy and chemotherapy

OBJECTIVE

To retrospectively evaluate the association of MRI findings with local control of nasopharyngeal carcinoma (NPC) treated with radiation therapy and chemotherapy (chemoradiotherapy).

METHODS

Pre-treatment MRIs of 101 patients (78 males and 23 females, 23-79 years of age) who had NPC treated with chemoradiotherapy were retrospectively reviewed to evaluate tumour involvement of nasopharyngeal anatomic subsites, tumour volume and MRI appearance. Local control rates were evaluated with respect to these MRI findings.

RESULTS

Univariate analysis (using the Kaplan-Meier method) showed that invasion of the skull base as determined by MRI was a significant predictor of local control. In terms of clinical characteristics, T stage and pathological subtype were significant predictors of local control. Multivariate analysis (Cox regression model) of the radiologic findings and clinical characteristics revealed that invasion of the skull base (p = 0.003) and pathological subtype (p < 0.001) were independent prognostic factors for local control.

CONCLUSION

Invasion of the skull base as determined by MRI predicts the likelihood of local failure and may be helpful in identifying a subset of patients with tumours at risk of local recurrence within 3 years after primary chemoradiotherapy.

ADVANCES IN KNOWLEDGE

It has now become common practice to use MRI for pre-treatment evaluation of patients with NPC. The potential role for MRI findings in predicting local control and prognosis in patients with NPC has implications for treatment planning.

Local failure patterns for patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy

Background

To investigate the clinical feature and the local failure patterns after intensity-modulated radiotherapy for nasopharyngeal carcinoma.

Methods

Between March 2007 and July 2009, 710 patients with nasopharyngeal carcinoma were treated with intensity-modulated radiotherapy. The magnetic resonance imagings obtained at recurrence were registered with the original planning computed tomography for dosimetry analysis.

Results

With a median follow-up of 38 months, 34 patients have developed local recurrence (32 cases valid). The incidence of invasion to nasopharynx, parapharyngeal space and the retropharyngeal space by the primary tumors was 100%, 75.0% and 62.5%, respectively, but 78.1%, 34.4% and 21.9% at recurrence, respectively. The rate of invasion to ethmoid sinus was 3.1% by the primary tumors but 28.1% at recurrence (p = 0.005). The topographic analysis of the local failure patterns showed "central" in 16 patients; "marginal" in 9; and "outside" in 7. The median volumes of primary gross tumor were 45.84 cm³ in the central failure group, 29.44 cm³ in the marginal failure group, and 21.52 cm³ in the outside failure group, respectively (p = 0.012), and the median volumes of primary clinical target1 were 87.28 cm³, 61.90 cm³ and 58.74 cm³ in the three groups, respectively (p = 0.033).

Conclusions

In patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy, the recurrent tumors had their unique characteristic and regularity of invasion to adjacent structures. "Central" failure was the major local failure pattern. The volumes of primary gross tumor and clinical target1 were significantly correlated with recurrent patterns. Employ more aggressive approaches to tumor cells which will be insensitive to radiotherapy may be an effective way to reduce the central failure.

Primary tumor regression speed after radiotherapy and its prognostic significance in nasopharyngeal carcinoma: a retrospective study

BACKGROUND

To observe the primary tumor (PT) regression speed after radiotherapy (RT) in nasopharyngeal carcinoma (NPC) and evaluate its prognostic significance.

METHODS

One hundred and eighty-eight consecutive newly diagnosed NPC patients were reviewed retrospectively. All patients underwent magnetic resonance imaging and fiberscope examination of the nasopharynx before RT, during RT when the accumulated dose was 46-50 Gy, at the end of RT, and 3-4 months after RT.

RESULTS

Of 188 patients, 40.4% had complete response of PT (CRPT), 44.7% had partial response of PT (PRPT), and 14.9% had stable disease of PT (SDPT) at the end of RT. The 5-year overall survival (OS) rates for patients with CRPT, PRPT, and SDPT at the end of RT were 84.0%, 70.7%, and 44.3%, respectively (P < 0.001, hazard ratio [HR] = 2.177, 95% confidence interval [CI] = 1.480-3.202). The 5-year failure-free survival (FFS) and distant metastasis-free survival (DMFS) rates also differed significantly (87.8% vs. 74.3% vs. 52.7%, P = 0.001, HR = 2.148, 95% CI, 1.384-3.333; 91.7% vs. 84.7% vs. 66.1%, P = 0.004, HR = 2.252, 95% CI = 1.296-3.912). The 5-year local relapse-free survival (LRFS) rates were not significantly different (95.8% vs. 86.0% vs. 81.8%, P = 0.137, HR = 1.975, 95% CI, 0.976-3.995). By multivariate analyses, the PT regression speed at the end of RT was the only independent prognostic factor of OS, FFS, and DMFS (P < 0.001, P = 0.001, and P = 0.004, respectively). The 5-year FFS rates for patients with CRPT during RT and CRPT only at the end of RT were 80.2% and 97.1%, respectively (P = 0.033). For patients with persistent PT at the end of RT, the 5-year LRFS rates of patients without and with boost irradiation were 87.1% and 84.6%, respectively (P = 0.812).

CONCLUSIONS

PT regression speed at the end of RT was an independent prognostic factor of OS, FFS, and DMFS in NPC patients. Immediate strengthening treatment may be provided to patients with poor tumor regression at the end of RT.

The role of tumor volume in radiotherapy of patients with head and neck cancer

The assumption that the larger tumor contains a higher number of clonogenic cells what may deteriorate prognosis of patients treated with RT has been confirmed in many clinical studies. Significant prognostic influence of tumor volume (TV) on radiotherapy (RT) outcome has been found for tumors of different localizations including patients with head and neck cancer (HNC). Although TV usually is a stronger prognostic factor than T stage, commonly used TNM classification system dose not incorporate TV data. The aim of the paper is to refresh clinical data regarding the role of TV in RT of patients with HNC. At present somehow new meaning of TV could be employed in the aspect of modern RT techniques and combined treatment strategies. For larger TV more aggressive treatment options may be considered. In modern RT techniques escalated dose could be provided highly conformal or RT can be combined with systemic treatment increasing therapeutic ratio. In the study several reports estimating prognostic value of TV for patients with HNC treated with RT has been reviewed.Due to substantially various reported groups of patients as to tumor site, stage of disease or treatment strategies, precise cut-off value could not be establish in general, but the significant association between TV and treatment outcome had been found in almost all studies. There is a strong suggestion that TV should supplement clinical decision in the choice of optimal treatment strategy for patients with HNC.

Region-based nasopharyngeal carcinoma lesion segmentation from MRI using clustering- and classification-based methods with learning

In clinical diagnosis of nasopharyngeal carcinoma (NPC) lesion, clinicians are often required to delineate boundaries of NPC on a number of tumor-bearing magnetic resonance images, which is a tedious and time-consuming procedure highly depending on expertise and experience of clinicians. Computer-aided tumor segmentation methods (either contour-based or region-based) are necessary to alleviate clinicians' workload. For contour-based methods, a minimal user interaction to draw an initial contour inside or outside the tumor lesion for further curve evolution to match the tumor boundary is preferred, but parameters within most of these methods require manual adjustment, which is technically burdensome for clinicians without specific knowledge. Therefore, segmentation methods with a minimal user interaction as well as automatic parameters adjustment are often favored in clinical practice. In this paper, two region-based methods with parameters learning are introduced for NPC segmentation. Two hundred fifty-three MRI slices containing NPC lesion are utilized for evaluating the performance of the two methods, as well as being compared with other similar region-based tumor segmentation methods. Experimental results demonstrate the superiority of adopting learning in the two introduced methods. Also, they achieve comparable segmentation performance from a statistical point of view.