Prognostic value of prepontine cistern invasion in nasopharyngeal carcinoma treated by intensity-modulated radiotherapy

Prognostic value of MR-detected mandibular nerve involvement: potential indication for future individual induction chemotherapy in T4 nasopharyngeal carcinoma

PURPOSE

To investigate the prognostic significance of MR-detected mandibular nerve involvement (MNI) and its value for induction chemotherapy (IC) administration in patients with nasopharyngeal carcinoma (NPC) and T4 disease.

METHODS

This retrospective study enrolled 792 non-metastatic, biopsy-proven NPC patients. Univariate and multivariate analysis were used to evaluate potential prognosticators. The inter-observer agreement was assessed by the kappa values.

RESULTS

MR-detected MNI was observed in 141 (72.3%) patients among 195 patients with T4 disease, with excellent agreement between the readers (kappa = 0.926). Patients with MR-detected MNI presented better 5-year overall survival (OS) (hazard ratio [HR], 0.40; P = 0.006) than those with MR-negative MNI. Of these patients, IC treatment was verified as an independent factor (HR: 0.35; P = 0.014) with preferable effect on OS.

CONCLUSION

MR-detected MNI could serve as an independent favorable prognostic predictor for OS in NPC patients with stage T4, which should be considered for stratifying these patients for IC administration.

Adding Concurrent Chemotherapy to Intensity-Modulated Radiotherapy Does Not Improve Treatment Outcomes for Stage II Nasopharyngeal Carcinoma: A Phase 2 Multicenter Clinical Trial

Purpose: To explore the efficacy of concomitant chemotherapy in intensity-modulated radiotherapy (IMRT) to treat stage II nasopharyngeal carcinoma (NPC). Methods and Materials: In this randomized phase 2 study [registered with ClinicalTrials.gov (NCT01187238)], eligible patients with stage II (2010 UICC/AJCC) NPC were randomly assigned to either IMRT alone (RT group) or IMRT combined with concurrent cisplatin (40 mg/m², weekly) (CCRT group). The primary endpoint was overall survival (OS). The second endpoints included local failure-free survival (LFFS), regional failure-free survival (RFFS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and acute toxicities. Results: Between May 2010 to July 2012, 84 patients who met the criteria were randomized to the RT group (n = 43) or the CCRT group (n = 41). The median follow-up time was 75 months. The OS, LFFS, RFFS, DFS, and DMFS for the RT group and CCRT group were 100% vs. 94.0% (p = 0.25), 93.0% vs. 89.3% (p = 0.79), 97.7% vs. 95.1% (p = 0.54), 90.4% vs. 86.6% (p = 0.72), and 95.2% vs. 94.5% (p = 0.77), respectively. A total of 14 patients experienced disease failure, 7 patients in each group. The incidence of grade 2 to 4 leukopenia was higher in the CCRT group (p = 0.022). No significant differences in liver, renal, skin, or mucosal toxicity was observed between the two groups. Conclusion: For patients with stage II NPC, concomitant chemotherapy with IMRT did not improve survival or disease control but had a detrimental effect on bone marrow function.

Lymph node-to-primary tumor standardized uptake value ratio on PET predicts distant metastasis in nasopharyngeal carcinoma

OBJECTIVES

To investigate the prognostic value of the relative maximum standardized uptake value (SUV) ratio between neck lymph node and primary tumor (NTR) measured by pretreatment ¹⁸F-FDG PET in patients with nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

We retrospectively reviewed patients with non-disseminated NPC who underwent PET scans before radical intensity-modulated radiotherapy (IMRT). Receiver operating characteristic analysis was performed to identify the optimal cut-off value for NTR. The prognostic value of NTR for distant metastasis-free survival (DMFS) was evaluated using Kaplan-Meier method for survival analyses and Cox regression for multivariable analysis.

RESULTS

Among the 437 eligible patients, the median follow-up time was 62.9 (range, 2.1-113.0) months. Patients with high NTR (NTR > 0.9181) experienced significantly worse DMFS (5-year 80.5% vs. 91.6%, P < 0.001). In the subgroup analysis, we found that patients with high NTR had significantly lower DMFS in T1-2 category (5-year 86.1% vs. 98.1%, P = 0.002), T3-4 category (5-year 71.5% vs. 86.2%, P = 0.010), N2-3 category (5-year 75.3% vs. 86.2%, P = 0.048), and stage IVA-B (5-year 69.8% vs. 85.4%, P = 0.012). Multivariable analysis showed that NTR was an independent prognostic factor for DMFS (HR 2.20, 95% CI 1.20-4.03, P = 0.011).

CONCLUSION

Pretreatment NTR is an easily accessible but potential prognosticator for DMFS in NPC patients treated by IMRT, which may help in providing more personalized treatment or designing future clinical trials.

Long-term survival and late complications of intensity-modulated radiotherapy for recurrent nasopharyngeal carcinoma

BACKGROUND

To evaluate the effectiveness and toxicities of intensity-modulated radiotherapy (IMRT) for locally recurrent nasopharyngeal carcinoma (NPC).

METHODS

One hundred and eighty-four previously irradiated NPC patients with recurrent disease and re-irradiated by IMRT between February 2005 to May 2013 had been reviewed. The disease was re-staged I in 33, II in 27, III in 70 and IV in 54 patients. Seventy-five percent of the patients received cisplatin-based chemotherapy.

RESULTS

The median survival time was 33 months. The 3-year actuarial rates of local recurrence-free survival (LRFS), distant metastases-free survival (DMFS), and overall survival (OS) rates were 85.1, 91.1, and 46.0%, respectively. About 53% of the patients experienced Grade 3-4 late toxicities. Forty-four patients died of massive hemorrhage of the nasopharynx caused by radiation induced mucosal necrosis. Multivariate analysis indicated that chemotherapy and time interval between initial radiotherapy and re-irradiation were independent predictors for DMFS.

CONCLUSION

IMRT is an effective method for patients with locally recurrent NPC. Massive hemorrhage of the nasopharynx is the major sever late complication and also the leading cause of death. Early recurrence is negative factor for DMFS. Combination of chemotherapy can improve DMFS, but not for OS. Optimal salvage treatment strategies focusing on improvement of survival and minimization of late toxicities are warranted.

An elective radiation dose of 46 Gy is feasible in nasopharyngeal carcinoma treated by intensity-modulated radiotherapy: A long-term follow-up result

The purpose of this study is to compare the treatment outcome of different radiation doses of elective neck irradiation (ENI) in nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT).In total, 504 patients with nondisseminated NPC who underwent magnetic resonance imaging before radical IMRT between 2000 and 2008 were retrospectively reviewed. The patients were classified into 2 groups based on the ENI dose: low ENI when the ENI dose was 46 Gy (n = 446) and high ENI when the ENI doses were 50 to 60 Gy (n = 58). All the patients in both the groups received a median dose of 72 Gy to the gross tumor and involved nodes. The fraction size was 2 Gy per fraction. Matching was performed between low ENI and high ENI in a 2:1 ratio, and the matching criteria were N-stage, T-stage, treatment modality, pathology classification, sex, and age.The median follow-up for all patients was 63.5 months. In all patients, the 5-year progression-free survival (PFS), local control (LC), regional control (RC), distant metastasis-free survival (DMFS), overall survival (OS), and cancer-specific survival (CSS) for low ENI and high ENI patients were 69.0% and 63.2% (P = 0.331), 89.0% and 83.9% (P = 0.235), 90.1% and 85.2% (P = 0.246), 86.8% and 76.6% (P = 0.056), 77.5% and 80.8% (P = 0.926), and 84.4% and 82.5% (P = 0.237), respectively. In the matched-pair analysis, the 5-year PFS, LC, RC, DMFS, OS, and CSS for matched low ENI and high ENI patients were 74.1% and 63.2% (P = 0.134), 92.0% and 83.9% (P = 0.152), 90.1% and 85.2% (P = 0.356), 86.2% and 76.6% (P = 0.125), 87.0% and 80.8% (P = 0.102), and 88.6% and 82.5% (P = 0.080), respectively. In the multivariable analysis for all patients, the ENI group was not a significant factor for PFS, LC, RC, DMFS, OS, and CSS.A low ENI dose of 46 Gy in 23 fractions is feasible in NPC patients treated with IMRT, and this concept should be validated in the prospective studies.

Magnetic Resonance Imaging-Detected Intracranial Extension in the T4 Classification Nasopharyngeal Carcinoma with Intensity-Modulated Radiotherapy

PURPOSE

This study was conducted is to identify the prognostic value and staging categories of magnetic resonance imaging (MRI)-detected intracranial extension in nasopharyngeal carcinoma (NPC) with intensity-modulated radiotherapy (IMRT) to determine whether it is necessary to subclassify the T4 classification NPC.

MATERIALS AND METHODS

A total of 335 nonmetastatic T4 classification NPC patients with MRI treated between March 2004 and June 2011 by radical IMRT were included. The T4 classification patients were subclassified into two grades (T4a, without intracranial extension vs. T4b, with intracranial extension) according to the site of invasion.

RESULTS

The frequency of intracranial extension was 40.9% (137 of 335 patients). Multivariate analysis identified subclassification (T4a vs. T4b) as an independent prognostic factor for local failure-free survival (p=0.049; hazard ratio [HR], 0.498) and overall survival (p=0.004; HR, 0.572); however, it had no effect on regional failure-free survival or distant failure-free survival (p > 0.050).

CONCLUSION

For patients with T4 classification NPC, those with MRI-detected intracranial extension are more likely to experience local failure and death after IMRT than patients without intracranial extension. According to the site of invasion, subclassification of T4 patients as T4a or T4b has prognostic value in NPC.

Prognostic Value of Cavernous Sinus Invasion in Patients with Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy

Purpose

To investigate the prognostic value of cavernoussinus invasion (CSI) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).

Patients and Methods

Retrospective review of data from 1,087 patients with biopsy-proven, non-metastatic NPC. All patients were diagnosed using magnetic resonance imaging (MRI) scans and received IMRT as the primary treatment.

Results

The incidence of cavernoussinus invasion in this cohort was 12.1%. In univariate analysis, 5-year overall survival (OS) (70.6% vs. 88.5%, P < 0.001) and distant metastasis-free survival (DMFS) (71.4% vs. 87.7%, P < 0.001), but not locoregional relapse-free survival (LRFS) (93.9% vs. 93.7%, P = 0.341), were significantly different between patients with and without cavernoussinus invasion. In the T4 subgroup, the 5-year OS, DMFS, and LRFS of patients with and without cavernoussinus extension were 70.6% vs. 81.9% (P = 0.011), 71.4% vs. 84.1% (P = 0.011), and 91.2% vs. 89.7% (P = 0.501), respectively. In multivariate analysis, cavernoussinus invasion was an independent prognostic factor for poorer OS (HR = 1.782; P = 0.013) and DMFS (HR = 1.771; P = 0.016), but not LRFS (HR = 0.632; P = 0.294). In patients with lymph node metastasis, the DMFS rates of patients with and without cavernoussinus invasion were significantly different (P < 0.001). Preliminaryanalysis indicated that neoadjuvant chemotherapy led to better DMFS and OS in patients with cavernoussinus invasion than concurrent chemotherapy or radiotherapy alone; however, the differences were not significant.

Conclusions

In the IMRT era, cavernoussinus invasion remains a prognostic factor for poor DMFS and OS in NPC, even in patients with T4 disease.