Paranasopharyngeal space involvement in nasopharyngeal cancer: detection by CT and MRI

Nasopharyngeal Carcinoma in Children, Current Treatment Approach

Nasopharyngeal carcinoma (NPC) is a rare and locally aggressive form of childhood cancer. Treatment of pediatric NPC includes chemotherapy and radiotherapy. Most studies on the treatment of pediatric NPC are single-arm studies. With current treatment protocols survival rates for patients with nonmetastatic disease exceed 80%, although most children will have long-term treatment-related late effects. Efforts to reduce early and late toxicities include reduced radiotherapy doses in children with good responses to induction chemotherapy. Further studies are needed to evaluate the role of immunotherapy in both the primary setting and in children with progressive or relapsed disease. This review summarizes current clinical approaches to the treatment of pediatric NPC.

Nasopharyngeal carcinoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Nasopharyngeal carcinoma (NPC) is a rare pediatric tumor. Collaborative studies performed over the last decades showed improved results compared to historical data, but standardized guidelines for diagnosis and management of pediatric NPC are still unavailable. This study presents a European consensus guideline for the diagnosis and treatment of pediatric NPC developed by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT). Main recommendations include induction chemotherapy with cisplatin and 5-flurouracil, concomitant chemoradiotherapy in advanced disease, and to consider maintenance treatment with interferon beta (IFN-β) for selected high-risk patients. Dose adjustments of radiotherapy based on response to induction chemotherapy may decrease the rates of long-term treatment-related complications that affect most of the survivors.

Skeletal muscle mass and sarcopenia can be determined with 1.5-T and 3-T neck MRI scans, in the event that no neck CT scan is performed

Objectives

Cross-sectional area (CSA) measurements of the neck musculature at the level of third cervical vertebra (C3) on CT scans are used to diagnose radiological sarcopenia, which is related to multiple adverse outcomes in head and neck cancer (HNC) patients. Alternatively, these assessments are performed with neck MRI, which has not been validated so far. For that, the objective was to evaluate whether skeletal muscle mass and sarcopenia can be assessed on neck MRI scans.

Methods

HNC patients were included between November 2014 and November 2018 from a prospective data-biobank. CSAs of the neck musculature at the C3 level were measured on CT (n = 125) and MRI neck scans (n = 92 on 1.5-T, n = 33 on 3-T). Measurements were converted into skeletal muscle index (SMI), and sarcopenia was defined (SMI < 43.2 cm²/m²). Pearson correlation coefficients, Bland–Altman plots, McNemar test, Cohen’s kappa coefficients, and interclass correlation coefficients (ICCs) were estimated.

Results

CT and MRI correlated highly on CSA and SMI (r = 0.958–0.998, p < 0.001). The Bland–Altman plots showed a nihil mean ΔSMI (− 0.13–0.44 cm²/m²). There was no significant difference between CT and MRI in diagnosing sarcopenia (McNemar, p = 0.5–1.0). Agreement on sarcopenia diagnosis was good with κ = 0.956–0.978 and κ = 0.870–0.933, for 1.5-T and 3-T respectively. Observer ICCs in MRI were excellent. In general, T2-weighted images had the best correlation and agreement with CT.

Conclusions

Skeletal muscle mass and sarcopenia can interchangeably be assessed on CT and 1.5-T and 3-T MRI neck scans. This allows future clinical outcome assessment during treatment irrespective of used modality.

Key Points

• Screening for low amount of skeletal muscle mass is usually measured on neck CT scans and is highly clinical relevant as it is related to multiple adverse outcomes in head and neck cancer patients.

• We found that skeletal muscle mass and sarcopenia determined on CT and 1.5-T and 3-T MRI neck scans at the C3 level can be used interchangeably.

• When CT imaging of the neck is missing for skeletal muscle mass analysis, patients can be assessed with 1.5-T or 3-T neck MRIs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07440-1.

The value of CT, MRI, and PET-CT in detecting retropharyngeal lymph node metastasis of head and neck squamous cell carcinoma

BACKGROUND

The diagnostic accuracies of the imaging studies should be clearly acknowledged in managing head and neck cancer patients; however, the accuracies of preoperative imaging studies in detecting retropharyngeal lymph node (RPLN) metastasis are still not clarified. This study was to evaluate diagnostic accuracies of computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT) in detecting RPLN metastasis of head and neck squamous cell carcinomas.

METHODS

For 123 patients who had performed RPLN dissection during the surgery of their squamous cell carcinoma of the head and neck, preoperative CT, MRI, and/or PET-CT were reviewed for RPLN metastasis in a blinded fashion by one experienced radiologist. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of each imaging modality were assessed, by comparing with the histopathologic findings of the resected RPLNs that served as the standard of reference.

RESULTS

RPLNs were pathologically positive for metastasis in 43 of the 123 patients (35%). Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy in detecting metastasis to RPLN were 65, 94, 85, 83, and 84% for CT; 74, 94, 87, 87 and 87% for MRI; 83, 93, 89, 89 and 89% for PET-CT, respectively. When all the three imaging modalities were considered together (n = 74), they offered sensitivity of 90%, specificity of 91%, positive predictive value of 87%, negative predictive value of 93%, and accuracy of 91%.

CONCLUSIONS

The preoperative imaging studies offered relatively high specificity rates, but rather low sensitivity rates. The three imaging modalities altogether increased diagnostic accuracies, which highlights the potential of the three studies when used altogether can minimize missed diagnoses of RPLN metastasis.

The evolution of nasopharyngeal carcinoma staging

The prevalence of nasopharyngeal carcinoma is characterized by an unbalanced distribution: the disease is particularly prevalent in East and Southeast Asia. In this article, we review the evolution of the International Union Against Cancer/American Joint Committee on Cancer staging system for nasopharyngeal carcinoma. With the increasing using of newer imaging methods, more advanced radiotherapy techniques and systemic chemotherapy, we also discuss newer clinical features that might affect staging. Finally, we propose the future direction of staging and potential prognostic factors that have a major influence on the treatment outcomes of this disease.

Is Unenhanced 18F-FDG–PET/CT Better than Enhanced CT in the Detection of Retropharyngeal Lymph node Metastasis in Nasopharyngeal Carcinoma?

Positron-emission tomography/computed tomography (PET/CT) has been proposed as a means to enhance the pretreatment evaluation of cervical lymph node status in patients with nasopharyngeal carcinoma (NPC). We conducted a prospective study to compare PET/CT and enhanced CT for the detection of retropharyngeal lymph node (RLN) metastasis in NPC, and to ascertain the factors that affect its diagnostic performance. Our study population was made up of 33 patients—24 men and 9 women, aged 30 to 81 years (mean: 52)—with newly diagnosed NPC who had been treated over a 2-year period. All patients underwent enhanced CT first, followed by unenhanced 18F-fluorodeoxyglucose (FDG) PET/CT. The detection rate of RLN metastasis on PET/CT was significantly lower than that on enhanced CT (36.4 vs. 75.8%; p < 0.001). A total of 25 of 26 nodes with a discordant finding were negative on PET/CT; they included 13 metastatic lymph nodes with low FDG uptake, 9 that were located close to the primary tumor, 2 that were confluent RLNs, and 1 that was adjacent to the physiologic FDG-avid prevertebral muscle. The maximum standardized uptake value (SUVmax) of RLNs was positively correlated with the minimum axial diameter (r = 0.803, p < 0.001). The PET/CT detection rate was 0% for lymph nodes smaller than 5 mm, 9% for those 5 to 10 mm, and 73% for those 1 cm or larger. The detection rate of PET/ CT at level C1 was significantly lower than that at C2 (22 vs. 67%; p = 0.035). We conclude that unenhanced PET/CT is markedly inferior to enhanced CT for detecting RLN metastasis in NPC, especially in lymph nodes with a minimum axial diameter of less than 1 cm and those in proximity to the primary tumor. Using enhanced CT in PET/CT is justified to improve the recognition of RLN metastasis in patients with NPC.

Nasopharyngeal carcinoma patients with retropharyngeal lymph node metastases: a minimum axial diameter of 6 mm is a more accurate prognostic predictor than 5 mm

OBJECTIVE

The criteria for the diagnosis of metastatic retropharyngeal lymph nodes (RLNs) have not yet been resolved and are not included in the current edition of the American Joint Committee on Cancer (AJCC) staging system (seventh edition) for the staging of nasopharyngeal carcinoma (NPC). The aim of this study was to use MRI to identify an RLN size criterion that can accurately predict prognosis in patients with NPC.

MATERIALS AND METHODS

Eight hundred seventeen patients with newly diagnosed localized NPC were identified. All of the patients underwent MRI before treatment with definitive radiation therapy. All the MRI studies and medical records were reviewed retrospectively. Overall survival (OS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS) were assessed using SPSS software (version 17.0).

RESULTS

RLN size cutoffs of ≥ 5 mm and of ≥ 6 mm were used. There was no significant difference in OS (p = 0.216), DMFS (p = 0.081), or LRFS (p = 0.067) in patients with RLNs ≥ 5 mm and in those with RLNs < 5 mm. When 6 mm was used as a size cutoff, significant differences in OS (p = 0.000) and DMFS (p = 0.001) were identified; there was no significant difference observed for LRFS (p = 0.380).

CONCLUSION

A minimum axial RLN diameter of 6 mm was a more accurate prognostic predictor in NPC patients with RLN metastases than 5 mm.

Sonographic findings of nasopharyngeal carcinoma and its involvement in the parapharyngeal space

OBJECTIVES

The purpose of this study was to determine the sonographic performance in pathologically proven cases of nasopharyngeal carcinoma and its involvement in the parapharyngeal space.

METHODS

The study included 58 patients being treated for suspected nasopharyngeal carcinoma detected by routine nasopharyngoscopy who underwent pathologic biopsy. Sonography was performed immediately thereafter with a convex array transducer in both the B-mode and color mode. Forty-five of the 58 patients (90 parapharyngeal spaces) in whom nasopharyngeal carcinoma was proved by both sonography and pathologic biopsy underwent preradiotherapy magnetic resonance imaging (MRI). The sonographic findings were compared to the pathologic findings. The sonographic findings of parapharyngeal space involvement were correlated with the MRI findings.

RESULTS

The normal anatomy of the nasopharynx and parapharyngeal space, nasopharyngeal carcinoma, and its relationship with the parapharyngeal space were well shown on sonography. The sensitivity of sonography for detection of nasopharyngeal carcinoma was 97.8%, and the specificity was 41.7%. The sonographic findings of parapharyngeal space involvement had a high degree of agreement with MRI (κ = 0.757; P < .001).

CONCLUSIONS

These promising initial data indicate that sonography may be a useful tool for diagnosing nasopharyngeal carcinoma and defining the relationship between the tumor and the parapharyngeal space.

Prognostic significance of maximum primary tumor diameter in nasopharyngeal carcinoma

Background

To evaluate the prognostic value of maximum primary tumor diameter (MPTD) in nasopharyngeal carcinoma (NPC).

Methods

Three hundred and thirty-three consecutive, newly-diagnosed NPC patients were retrospectively reviewed. Kaplan-Meier analysis and the log-rank test were used to estimate overall survival (OS), failure-free survival (FFS), distant metastasis-free survival (DMFS) and local relapse-free survival (LRFS). Cox proportional hazards regression analysis was used to assess the prognostic value of MPTD.

Results

Median follow-up was 66 months (range, 2–82 months). Median MPTD in stage T1, T2, T3 and T4 was 27.9, 37.5, 45.0 and 61.3 mm, respectively. The proportion of T1 patients with a MPTD ≤ 30 mm was 62.3%; 72% and 62.9% of T2 and T3 patients had a MPTD > 30–50 mm, and 83.5% of T4 patients had a MPTD > 50 mm. For patients with a MPTD ≤ 30 mm, > 30–50 mm and > 50 mm, the 5-year OS, FFS, DMFS and LRFS rates were 85.2%, 74.2% and 56.3% (P < 0.001); 87%, 80.7% and 62.8% (P < 0.001); 88.7%, 86.4% and 72.5% (P = 0.003); and 98.2%, 93.2% and 86.3% (P = 0.012), respectively. In multivariate analysis, MPTD was a prognostic factor for OS, FFS and DMFS, and the only independent prognostic factor for LRFS. For T3-T4 patients with a MPTD ≤ 50 mm and > 50 mm, the 5-year OS, FFS and DMFS rates were 70.4% vs. 58.4% (P = 0.010), 77.5% vs. 65.2% (P = 0.013) and 83.6% vs. 73.6% (P = 0.047), respectively. In patients with a MPTD ≤ 30 mm, 5-year LRFS in T1, T2, T3 and T4 was 100%, 100%, 88.9% and 100% (P = 0.172).

Conclusions

Our data suggest that MPTD is an independent prognostic factor in NPC, and incorporation of MPTD might lead to a further refinement of T staging.

Prognostic significance of the various classifications for parapharyngeal space involvement in nasopharyngeal carcinoma

CONCLUSION

Advanced parapharyngeal space (PPS) involvement showed stronger prognostic value than PPS involvement. The classification of PPS involvement proposed by Min or Sham was the most appropriate classification for parapharyngeal extension in nasopharyngeal carcinoma (NPC). The degree of tumor extension into the PPS should be considered in future TNM staging revisions.

OBJECTIVES

This study was conducted to evaluate the prognostic significance of the various classifications for PPS involvement in patients with NPC.

METHODS

From January to July 2000, a total of 176 patients with pathologically diagnosed NPC were prospectively enrolled in this study. The extent of PPS involvement was examined by contrast-enhanced computed tomography (CT) scan and graded according to the four previously reported classifications (Min, Sham, Xiao, and Heng).

RESULTS

The incidence of PPS involvement was 81.8%. The 5-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and local relapse-free survival rates (LRFS) of the patients with and without PPS involvement were 68.1% and 90.2% (p = 0.010), 66.1% and 87.2% (p = 0.013), 76.7% and 93.6% (p = 0.032), and 84.9% and 93.1% (p = 0.220), respectively. Multivariate analysis showed that PPS involvement (yes vs no) was not an independent prognostic factor. However, graded PPS involvement was an independent factor affecting the prognosis of NPC. When the four classifications were included in a Cox model, it was shown that PPS involvement based on Min's classification was an independent factor for OS (p = 0.001). PPS involvement based on Sham's classification was an independent factor for PFS (p = 0.010) and DMFS (p = 0.009).

Magnetic resonance imaging features of nasopharyngeal carcinoma and nasopharyngeal non-Hodgkin's lymphoma: are there differences?

PURPOSE

To describe differences in the primary tumour and distribution of cervical lymphadenopathy for cases of nasopharyngeal carcinoma (NPC) and nasopharyngeal non-Hodgkin's lymphoma (NPNHL) using magnetic resonance (MR) imaging.

MATERIALS AND METHODS

MR images of patients with NPC (n = 272) and NPNHL (n = 118) were independently reviewed by two experienced radiologists.

RESULTS

NPC had a higher incidence of tumour invasion associated with the levator and tensor muscles of the velum palatine, the longus colli and medial pterygoid muscles, the base of the pterygoid process, the clivus, the base and greater wing of the sphenoid bone, the petrous apex, the foramen lacerum, the foramen ovale, the hypoglossal canal, and intracranial infiltration. In contrast, NPNHL had a higher incidence of tumour invasion associated with the hypopharynx, the palatine and lingual tonsils, as well as the ethmoid and maxillary sinuses. NPNHL also had a higher incidence of extensive and irregular bilateral lymphadenopathy, and lymphadenopathy in the parotid.

CONCLUSIONS

NPC more often involved an unsymmetrical tumour with a propensity to invade both widely and deeply into muscle tissue, the fat space, the neural foramen, and the skull base bone. In contrast, NPNHL tended to be a symmetrical and diffuse tumour with a propensity to spread laterally through the fat space and along the mucosa to the tonsils of the oropharynx and hypopharynx. These differences facilitate a differentiation of these diseases using MR images, and enhance our understanding of the biological behavior of these malignant tumours of the nasopharynx.

Magnetic resonance imaging staging of nasopharyngeal carcinoma in the head and neck

Magnetic resonance imaging (MRI) is the modality of choice for staging nasopharyngeal carcinoma in the head and neck. This article will review the patterns of primary and nodal spread on MRI with reference to the latest 7th edition of the International Union Against Cancer/American Joint Committee on Cancer staging system.

The prognostic influence of prevertebral space involvement in nasopharyngeal carcinoma

OBJECTIVES

The purpose of this study was to evaluate the effect of prevetebral space involvement on treatment outcomes in patients with nasopharyngeal carcinoma (NPC) who were treated with radiotherapy/concurrent chemoradiotherpy or concurrent chemoradiotherpy with adjuvant chemotherapy.

DESIGN

A retrospective review of case notes from the Kaohsiung Veterans General Hospital archives was performed.

SETTING

A medical centre in Taiwan.

PARTICIPANTS

There were 145 newly diagnosed cases of NPC. Thirty-nine patients were excluded because of the presence of distant metastasis at the time of presentation, loss of follow-up and incomplete image information.

MAIN OUTCOME MEASURES

Pearson's chi-square tests were used to analyse correlation between tumour invasion and prevetebral space involvement during univariate analysis and logistic regression was applied during multivariate analysis. Kaplan-Meier survival curves were constructed. Multivariate analysis was performed to examine the impact of various prognostic factors. Pearson's chi-square and Fisher's exact test were also used to evaluate the correlation between failure patterns and treatment modality.

RESULTS

A total of 106 patients with newly diagnosed NPC were enrolled in this study. Forty-three patients (41%) in this series were found to have prevertebral space involvement. Patients with prevertebral space involvement conferred a poor overall survival rate and metastasis-free survival rate compared with those without prevertebral space invasion (P = 0.04 and 0.02 respectively). Multivariate analysis showed that prevertebral space invasion was associated with an increased risk for distant metastasis [hazard ratio (HR) 14, 95% confidence interval (CI) 1.0-17.4; P = 0.03)] and overall survival (HR 7, 95% CI 1.1-135; P = 0.04). In patients with prevertebral space involvement, their metastasis-free survival rate, with and without adjuvant chemotherapy, was 100% and 72.7% (P = 0.047). This phenomenon was not observed in NPC patients without prevertebral space invasion.

CONCLUSIONS

The present data revealed that prevertebral space involvement has a close relationship with survival rates and recurrence rates of patients with NPC. Nasopharyngeal carcinoma patients with prevertebral space involvement have more recurrence and poorer survival rates and should be the group to benefit from concurrent chemoradiotherapy followed by adjuvant chemotherapy. Inclusion of prevertebral space involvement may be needed to predict prognosis of NPC and help us to identify the high-risk group.

Update on the management and therapeutic monitoring of advanced nasopharyngeal cancer

Despite being potentially curable at an early stage, more than 50% of patients who have nasopharyngeal carcinoma present with advanced locoregional disease, which results in a poor prognosis. This article discusses key advancements in the management of nasopharyngeal cancer, including the incorporation of concurrent chemoradiotherapy, new radiotherapy delivery techniques in the form of conformal and intensity-modulated radiotherapy, and salvage options for locoregional recurrence. New cytotoxic and targeted therapies that have resulted in improved survival in the metastatic setting are also described. The use of Epstein-Barr virus DNA for the prognostication and monitoring of nasopharyngeal cancer and the role of new diagnostic imaging techniques are also discussed.

[Nasopharyngeal carcinoma]

Nasopharyngeal carcinoma is relatively common. Undifferentiated Carcinomas of Nasopharyngeal Type (UNCT) are endemic Epstein-Barr virus (EBV)-related tumors. They are mainly radiosensitive. The role of imaging is to assess locoregional extension, TNM classification and adjust the radiation fields. MRI is essential to determine the initial extension. CT is useful to confirm the presence of bone involvement and evaluate nodal status. MRI and CT are necessary for the post-treatment follow-up.

Prognostic influence of parapharyngeal extension in nasopharyngeal carcinoma

CONCLUSIONS

Advanced parapharyngeal tumor involvement in nasopharyngeal carcinoma (NPC) had significant predictive value associated with poorer treatment outcome. Further subclassification of parapharyngeal invasion may be considered in the TNM staging system.

OBJECTIVES

We conducted a retrospective study to elucidate the effect of parapharyngeal extension on treatment outcomes in patients with NPC who were treated with radiotherapy or concurrent chemoradiotherapy (CCRT).

PATIENTS AND METHODS

A total of 99 patients with newly diagnosed NPC were enrolled in this study. The parapharyngeal space invasion examined by CT scan was identified and graded according to Sham and Choy's classification. Potentially significant parameters were analyzed by both univariate and multivariate methods using SPSS software.

RESULTS

The overall survival, recurrence-free survival, locoregional control survival and distant metastasis-free survival rates were affected by the presence of parapharyngeal space involvement (p<0.0001, p<0.0001, p<0.0001, p=0.002, respectively). In multivariate analysis accounting for all previously known prognostic factors, parapharyngeal invasion was associated with increased risk for any recurrence, locoregional recurrence, distant metastasis, and overall survival. After adjusting with TNM classification, parapharyngeal invasion was still an independent prognostic factor in NPC.

The impact of 18F-FDG PET/CT on assessment of nasopharyngeal carcinoma at diagnosis

The aim of this study was to determine whether the use of whole-body (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET)/CT alters staging and management of nasopharyngeal carcinoma (NPC) when compared with current staging practice. 52 patients with Stage III-IV NPC without distant metastases on chest X-ray/CT, abdominal ultrasound or bone scan were recruited for the study. Whole-body (18)F-FDG PET/CT and MRI of the head and neck were performed. The scans were compared for extent of the primary tumour (PT), cervical nodal metastases (CNM) and distant metastases (DM). Any discordance in results was assessed with respect to staging and impact on management. MRI and (18)F-FDG PET/CT scans were discordant in 28 (54%) patients. There was discordance in the extent of PT at 28 sites; in all sites, MRI showed more extensive tumour involving the nasopharynx (n = 8), skull base (n = 14), brain (n = 4) and orbit (n = 2). There was also variation among the extent of CNM in four nodes of the retropharyngeal region, with the nodes being positive on MRI. (18)F-FDG PET /CT did not identify any additional distant metastases but did identify a second primary tumour in the colon. The additional use of (18)F-FDG PET/CT did not "up-stage" the overall stage or change management in any patient. In conclusion, there is discordance between MRI and (18)F-FDG PET/CT, and the additional use of (18)F-FDG PET/CT for the current assessment of NPC at diagnosis does not appear to be justified in this cohort of patients.

Retropharyngeal lymph node metastasis in nasopharyngeal carcinoma: prognostic value and staging categories

PURPOSE

To investigate the incidence, prognostic value, and staging categories of retropharyngeal lymph node (RLN) metastasis in nasopharyngeal carcinoma (NPC).

EXPERIMENTAL DESIGN

We did a retrospective review of the data from 749 biopsy-proved nonmetastatic NPC patients. All patients had undergone contrast-enhanced computed tomography and had radiotherapy as their primary treatment.

RESULTS

The incidence of RLN metastasis was 51.5%. After adjusting for tumor (T) and node (N) classifications, a borderline significant difference of distant metastasis-free survival (DMFS) rates was observed between patients with or without RLN metastasis. In N(0) disease, the presence of RLN metastasis was a significant independent predictor for overall survival (OS), loco-regional relapse-free survival, and DMFS in multivariate Cox modeling analysis. No significant difference was observed in all end points between patients with unilateral and bilateral RLN metastasis. The hazard ratios of death and distant failure for N(0) with RLN metastasis were similar to N(1). The survival curve of OS and DMFS for N(0) disease with RLN metastasis had approximated that of N(1) disease. The survival curve of OS for T(1) disease with RLN metastasis was approximately the same as T(2) disease. However, the survival curve of DMFS for T(1) disease with RLN metastasis was approximately the same as in T(3) disease.

CONCLUSIONS

RLN metastasis has a tendency to affect the DMFS rates of patients with NPC. Retropharyngeal node involvement has a negative effect on the prognosis of N(0) disease. RLN metastasis should be classified as N(1).

N-staging by magnetic resonance imaging for patients with nasopharyngeal carcinoma: Pattern of nodal involvement by radiological levels

BACKGROUND AND PURPOSE

To study the pattern of lymphatic spread for patients with nasopharyngeal carcinoma (NPC), the significance of retropharyngeal node (RP-LN) involvement, and the possibility of replacing the supraclavicular fossa (SCF) by Levels IV and Vb (LL) as a demarcating criterion for N3-category.

PATIENTS AND METHODS

The magnetic resonance imagings (MRI) of 202 consecutive patients with NPC treated during 2001-2002 were retrospectively reviewed. Distribution in terms of radiological level (using the same criteria as other head and neck cancers) was mapped, and the size of individual node measured. Prognostic significance of RP-LN and LL was analyzed.

RESULTS

Only 4% of patients were node-negative on presentation. The nodal involvement occurred predominately at II (94%), III (85%) and RP-LN (80%). The presence of RP-LN affected the N-category in 3.5% of patients, and had no significant impact on tumor control. Replacing SCF by LL as one of the criteria for defining N3 is predictive for both distant control and overall survival.

CONCLUSIONS

With sensitive detection by MRI, the incidence of nodal involvement was very high for patients with NPC. It was difficult to isolate the prognostic significance of RP-LN. The current criterion for defining N3-category by extension into SCF or nodal size > 6 cm is the recommended standard, however replacing SCF with LL could be potentially useful and further validation is warranted.

Radiotherapy-related typing in 842 patients in canton with nasopharyngeal carcinoma

PURPOSE

The aim of this study was to propose the clinical radiotherapy-related typing and to summarize proportional distribution of radiotherapy-related types of nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

A total of 842 cases of NPC were randomly selected. According to 5-year follow-up results after radiotherapy, NPC was subdivided into four types: Type I (no primary and regional recurrence and no distant metastasis), Type II (primary or regional recurrence and no distant metastasis), Type III (no primary and regional recurrence, and distant metastasis), and Type IV (primary or regional recurrence, and distant metastasis). Proportion of the four types and relationship between this typing and Zhi-guang Xie typing were analyzed.

RESULTS

Distribution of radiotherapy-related types of NPC were 50.6%, 23.2%, 20.7%, and 5.6% for Types I, II, III, and IV, respectively. For Types D and AD of Zhi-guang Xie typing system and Stage III and IV of the 1992 Fuzhou staging system, the proportion of Type III was greater than that of Type II; and for Type A and Stage I and II, there was a larger proportion of Type II than that of Type III.

CONCLUSION

Radiotherapy-related typing, as a new clinical subclassification, could be supplementary for previous clinical typing and staging.

Head and neck cancer: how imaging predicts treatment outcome

Sophisticated imaging methods, such as computed tomography, magnetic resonance imaging and positron emission tomography, play an increasingly important role in the management of head and neck cancer. Pretreatment imaging findings have predictive value for patient outcome, independently from the currently used TNM classification, and may be used to tailor treatment to the individual patient. Based on per-treatment imaging, individualised replanning during radiotherapy may ameliorate tumour control rates and reduce toxic effects to normal tissues. Early posttreatment imaging studies contain important prognostic information, and allow selection of patients for further treatment or watchful waiting.

Staging of nasopharyngeal carcinoma investigated by magnetic resonance imaging

BACKGROUND AND PURPOSE

To investigate the American Joint Commission on Cancer (AJCC) sixth edition staging system of nasopharyngeal carcinoma (NPC) by Magnetic Resonance Imaging (MRI).

PATIENTS AND METHODS

One hundred and fifty-nine non-disseminated biopsy-proven NPC patients were studied with MRI before treatment. Retrieval of MRI information enabled us to restage all patients accurately according to the sixth edition of the AJCC staging system. Splitting the respective T and N stages by the significant defining factors identified, the cancer death hazard ratios were modeled by the Cox model in SPSS 10.0 for windows (SPSS Inc, Chicago, IL).

RESULTS

Single site of skull base abnormality (HR = 3.91, 95% CI: 0.74-20.56) has a superior result to others involved in T3 (HR = 5.83, 95% CI: 1.24-27.29). Involvement of either anterior or posterior cranial nerves solely (HR = 6.02, 95% CI: 1.55-35.60) was not found to be as a poor prognostic indicator as others involved in T4 (HR = 7.81, 95% CI: 1.81-33.63). Less than or equal to 3 cm of N1 (HR = 4.01, 95% CI: 0.48-33.83) and N2 (HR = 4.72, 95% CI: 0.62-35.78) have a better result than >3 cm of N1 (HR = 8.09, 95% CI: 0.95-68.97) and N2 (HR = 10.58, 95% CI: 1.32-84.62), respectively.

CONCLUSIONS

Perhaps, it is better to down-stage single site of skull base abnormality from T3 to T2, and involvement of either anterior or posterior cranial nerves solely from T4 to T3, meanwhile, < or =3 cm of N2 down-stage to N1, >3 cm of N1 up-stage to N2.

Sclerosis of the Pterygoid Process in Untreated Patients with Nasopharyngeal Carcinoma

PURPOSE

To retrospectively evaluate the prevalence of pterygoid process sclerosis in patients with untreated nasopharyngeal carcinoma.

MATERIALS AND METHODS

This retrospective HIPAA-compliant study was performed after the institutional review board deemed it to be exempt from review and patient informed consent. Contrast material-enhanced computed tomographic (CT) scans of the neck obtained in 31 patients (22 men, nine women; mean age, 42 years; age range, 27-68 years) with untreated nasopharyngeal carcinoma and in 31 control subjects (17 men, 14 women; mean age, 43 years; age range, 19-62 years) were evaluated independently by two neuroradiologists. The presence of sclerosis of the pterygoid process-defined as increased attenuation in the medullary cavity and/or thickening of the cortical bone-was assessed. Other findings noted included pterygoid process erosion, enhancing tumor adjacent to the pterygoid process, and CT evidence of parapharyngeal extension of the tumor. The data were evaluated by using generalized estimating equations based on a binary logistic regression model.

RESULTS

The prevalence of pterygoid process sclerosis averaged for the two readers was 60% (37 of 62 subjects) among the patients with nasopharyngeal carcinoma but only 3% (two of 62 subjects) among the control subjects, indicating a highly significantly increased prevalence (P < .001) of this finding in the patients with nasopharyngeal carcinoma. The overall prevalences of pterygoid process erosion, parapharyngeal extension of tumor, and enhancing tumor adjacent to the pterygoid process were 27% (17 of 62 subjects), 47% (29 of 62 subjects), and 77% (48 of 62 subjects), respectively. Pterygoid process sclerosis was the sole skull base abnormality in 36% (11 of 31) of the patients with nasopharyngeal carcinoma.

CONCLUSION

Sclerosis of the pterygoid process, which was present in about half of the patients with untreated nasopharyngeal carcinoma, may reflect tumor proximity to or tumor invasion of the pterygoid process.

Treatment outcomes and late complications of 849 patients with nasopharyngeal carcinoma treated with radiotherapy alone

PURPOSE

The objective of this study was to describe the treatment outcomes and treatment-related complications of nasopharyngeal carcinoma (NPC) patients treated with radiotherapy alone.

METHODS AND MATERIALS

Retrospective analysis was performed on 849 consecutive NPC patients treated between 1983 and 1998 in our institution. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded.

RESULTS

The 5-year overall and disease-free survival rates of these patients were 59% and 52%, respectively. Advanced parapharyngeal space (PPS) invasion showed stronger prognostic value than PPS invasion. Multiple neck lymph node (LN) involvement was demonstrated to be one of the most powerful independent prognostic factors among all LN-related parameters. External beam radiation dose more than 72 Gy was associated with significantly higher incidence of hearing impairment, trismus, and temporal lobe necrosis.

CONCLUSIONS

We recommend that the extent of PPS should be clarified and stratified. Multiple neck LN involvement could be integrated into the N-classification in further revisions of the American Joint Committee on Cancer stage. Boost irradiation is not suggested for node-negative necks. For node-positive necks, boost irradiation is indicated and a longer interval between initial and boost irradiation would reduce the incidence of neck fibrosis without compromising the neck control rate.

Nasopharyngeal carcinoma: the impact of CT-scan and of MRI on staging, radiotherapy treatment planning, and outcome of the disease

The present study is a critical review of the role of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis and therapy of nasopharyngeal cancer. It is estimated that following CT-scan/MRI, T,N staging of the disease changes in about half of cases, which results in important adjustments of the radiotherapy treatment planning, both in terms of radiation field dimensions and of dose specifications. The development of novel technology with CT-scan-simulated 3-D conformal or intensity-modulated radiotherapy (IMRT) planning is gradually becoming the standard therapy for nasopharyngeal carcinoma (NPC). CT-scan/MRI is also of value in detecting massive parapharyngeal involvement, low-neck lymphadenopathy or fixation of nodes onto adjacent structures, which are important features indicating the necessity to integrate chemotherapy or surgical neck dissection in the overall treatment policy. CT-positron emission tomography (PET) scan is recently under evaluation for the identification of the most active tumor regions, which will allow a biological radiotherapy planning (RTP) using IMRT techniques.

Phase II study of neoadjuvant carboplatin and paclitaxel followed by radiotherapy and concurrent cisplatin in patients with locoregionally advanced nasopharyngeal carcinoma: therapeutic monitoring with plasma Epstein-Barr virus DNA

PURPOSE

To assess the efficacy of neoadjuvant paclitaxel and carboplatin (TC) followed by concurrent cisplatin and radiotherapy (RT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) and to monitor treatment response with plasma Epstein-Barr virus (EBV) DNA.

PATIENTS AND METHODS

Thirty-one patients with International Union Against Cancer stages III and IV undifferentiated NPC had two cycles of paclitaxel (70 mg/m2 on days 1, 8, and 15) and carboplatin (area under the curve 6 mg/mL/min on day 1) on a 3-weekly cycle, followed by 6 to 8 weeks of cisplatin (40 mg/m2 weekly) and RT at 66 Gy in 2-Gy fractions. Plasma EBV DNA was measured serially using the real-time quantitative polymerase chain reaction method. Results All patients completed planned treatment. Response to neoadjuvant TC was as follows: 12 patients (39%) achieved partial response (PR) and 18 achieved (58%) complete response (CR) in regional nodes; five patients (16%) achieved PR and no patients achieved CR in nasopharynx. At 6 weeks after RT, one patient (3%) achieved PR and 30 patients (97%) achieved CR in regional nodes, and 31 patients (100%) achieved CR in nasopharynx; 29 patients (93%) had EBV DNA level of less than 500 copies/mL. Neoadjuvant TC was well tolerated, and the most common acute toxicity of cisplatin plus RT was grade 3 mucositis (55%). At median follow-up of 33.7 months (range, 7 to 39.3 months), six distant and three locoregional failures occurred. Plasma EBV DNA level increased significantly in eight of nine patients who experienced treatment failure but did not increase in those who did not. The 2-year overall and progression-free survival rates were 91.8% and 78.5%, respectively. CONCLUSION This strategy was feasible and resulted in excellent local tumor control. Serial plasma EBV DNA provides a noninvasive method of monitoring response in NPC.

Primary tumor volume of nasopharyngeal carcinoma: prognostic significance for local control

PURPOSE

To study the prognostic significance of primary tumor volume on local control of nasopharyngeal carcinoma.

METHODS AND MATERIALS

Between 1998 and 2001, 308 consecutive patients with nasopharyngeal carcinoma treated with radical intent were staged with MRI. On the basis of the extent of tumor infiltration outlined by a diagnostic radiologist, the gross tumor volume of the primary and involved retropharyngeal nodes (GTV-P) was delineated by a radiation oncologist for three-dimensional conformal radiotherapy to the nasopharyngeal region using the Helax-TMS Planning System. All patients were treated with 2 Gy daily to a total dose of 70 Gy in 6-7 weeks. Additionally, chemotherapy was given to 128 patients (42%).

RESULTS

The median GTV-P for the whole series was 22 cm(3) (range, 1.4-218 cm(3)). Although the GTV-P varied substantially within each T stage, the overall correlation between these two parameters was strongly significant (p <0.01), with the median GTV-P 2.7 cm(3) for T1, 13.2 cm(3) for T2, 28.1 cm(3) for T3, and 65.5 cm(3) for T4. With a median follow-up of 1.9 years (range, 0.1-3.9 years), the 3-year local failure-free rate was 87%. The 3-year local failure-free rate was 97% for patients with a GTV-P <15 cm(3) compared with 82% for those with a GTV-P > or =15 cm(3) (p <0.01). On multivariate analysis (with T stage as a covariate), GTV-P remained an independent prognostic factor for the local failure-free rate (hazard ratio, 1.01; 95% confidence interval, 1.00-1.02; p <0.01).

CONCLUSION

Our data suggested that GTV-P is a strongly significant factor for predicting local control of nasopharyngeal carcinoma. The risk of local failure was estimated to increase by 1% for every 1 cm(3) increase in primary tumor volume.

Nasopharynx

NPC represents 0.2% of malignant disease in the white population but is more common in southern China, among Chinese in East Asia and the United [figure: see text] States, and in North Africa, including Saudi Arabia. NPC in these ethnic groups tends to manifest at a younger age. Undifferentiated carcinoma is the most common histopathologic type and is associated with EBV. The tumor is optimally assessed with CT and MR imaging for staging; PET scanning provides optimal assessment of recurrent tumor or small lymph node metastases. The primary tumor in the nasopharynx may be small and infiltrating, causing no or only a small mass effect in the nasopharynx. In these cases, obliteration of fat planes and loss of muscle boundaries are important diagnostic findings, which are best evaluated with MR imaging including, Gd-DTPA with fat suppression. The size of the NPC varies from 1 to 2 cm to large tumors that extend to the oropharynx, PPS, nasal cavities, paranasal sinuses, and orbits. Skull base erosion is independent of the size of the nasopharyngeal tumor and ranges from slight erosion to extensive destruction. A concomitant finding is intracranial invasion, predominantly to the basal cisterns and cavernous sinuses associated with cranial nerve palsies. Intracranial invasion should be assessed with contrast MR imaging. Lymph node metastases in the neck are present in 90% of cases and are bilateral in 50% of cases. In a small percentage of cases, extension of lymph node metastases to the mediastinum and hilar areas are encountered. Distant metastases involve the lungs, skeleton, and liver, and occasionally the choroid. They are usually present at the initial presentation [figure: see text] and increase in frequency in advanced disease and in recurrent tumors. In addition, the metastatic lymph nodes in the neck reveal no specific imaging features that would allow differentiation from other lymph node metastases. They may be discrete, often multiple, and large and bulky displaying a variable degree of necrosis and enhancement following introduction of contrast material. Local recurrence manifests commonly within the first 2 to 3 years posttherapy and is optimally evaluated by MR imaging and PET scanning.

In-depth evaluation of the AJCC/UICC 1997 staging system of nasopharyngeal carcinoma: prognostic homogeneity and proposed refinements

PURPOSE

To critically evaluate the American Joint Commission on Cancer (AJCC)/International Union Against Cancer (UICC) 1997 staging system and look back on its achievements by comparing it with the AJCC/UICC 1992 and Ho 1978 staging systems. To identify areas for additional refinement, we analyzed the prognostic heterogeneity within each stage in depth, which provided important clues for the addition or better categorization of the different defining criteria.

METHODS AND MATERIALS

We performed a retrospective review of the data from 1294 consecutive biopsy-proven nonmetastatic nasopharyngeal carcinoma patients and staged the extent of disease according to the defining criteria of the three staging systems. All patients had undergone detailed pretreatment assessment by fiberoptic endoscopy and CT. Radical-intent radiotherapy was given using the Ho technique according to our standard protocol.

RESULTS

The AJCC/UICC 1997 staging system was superior to the other two staging systems, because it assigned patients to more uniform-size stage groupings and correlated better with prognosis. Parapharyngeal space involvement was not an independent predictor for survival, local control, or metastasis. On the other hand, carotid space involvement correlated with a greater likelihood of metastasis. Prognostic heterogeneity was found. Those with orbit, cranial nerve, or intracranial involvement fared worse within Stage T4; those with a maximal lymph node size >3 cm fared worse within Stage N2; and those with bilateral lymph node metastasis fared worse within Stage N3.

CONCLUSION

The prognostic accuracy of the AJCC/UICC 1997 staging system can be improved further by recategorization of the T, N, and group stage criteria.