Observer error in the assessment of nodal disease in head and neck cancer

Cervical lymph node evaluation and diagnosis

This article discusses the rationale for imaging cervical lymph nodes and reviews nodal anatomy and common drainage patterns, imaging features of pathologic lymph nodes, and the advantages of various imaging modalities available for evaluation and diagnosis of the lymph nodes.

MR elastography of the head and neck: driver design and initial results

PURPOSE

The purpose was to describe the design and fabrication of a driver suitable for magnetic resonance elastography (MRE) of the head and neck and to assess its performance in evaluating human parotid gland, lymph nodes and thyroid at 3.0 T.

MATERIALS AND METHODS

A head and neck driver was fabricated using a commercial transducer, headrest mould and piston extension. Driver performance was tested using a motion-sensitized spin-echo MRE pulse sequence. Six healthy volunteers and three patients (two metastatic nodes and one papillary carcinoma) were evaluated using MRE. Viscoelastic maps were computed to obtain storage modulus (G') and loss modulus (G") of the normal parotid and thyroid, metastatic node and thyroid cancer. Reproducibility was assessed by coefficient of variation.

RESULTS

All subjects completed MRE examination without discomfort. Initial G' and G" values were as follows: normal parotid gland, 1.12 kPa and 0.48 kPa; thyroid, 0.58 kPa and 0.42 kPa; metastatic node, 0.66 kPa and 0.58 kPa; and thyroid cancer, 0.17 kPa and 0.28 kPa. Based on parotid data, the coefficient of variation for G' and G" was 4.7% and 9.8%.

CONCLUSION

A new MRE driver for head and neck was successfully implemented, and our initial results suggested the device was suitable for the mechanical assessment of tissues in the head and neck.

Imaging of cervical lymph nodes in head and neck cancer: the basics

Imaging can identify pathologic cervical adenopathy in a significant number of patients with head and neck cancer who have no palpable adenopathy on physical examination. This article reviews nodal classification, drainage patterns of different head and neck cancers, various cross-sectional imaging features of metastatic lymph nodes from head and neck cancer, nodal staging, and certain features like extracapsular spread and carotid and vertebral invasion that the clinician should know because they have therapeutic and prognostic implications. New imaging techniques and the role of fluorodeoxyglucose positron emission tomography imaging in recurrent disease are discussed.

Staging N0 oral cancer: lymphoscintigraphy and conventional imaging

PURPOSE

To compare sentinel lymph node biopsy, magnetic resonance imaging (MRI), Doppler ultrasonography, and palpation as staging tools in patients with T1/T2 N0 cancer of the oral cavity.

MATERIAL AND METHODS

Forty consecutive patients were enrolled (17 F and 23 M, aged 32-90 years), 24 T1 and 16 T2 cN0 squamous cell carcinoma of the oral cavity. Palpation was carried out by two observers prior to inclusion. MRI, gray-scale and Doppler ultrasonography were performed. Lymphoscintigraphies were done after peritumoral injections of 99mTc labelled rheniumsulphide nanocolloid, followed by sentinel lymph node biopsy guided by a gamma probe and Patent Blue. Palpation, Doppler ultrasonography, MRI, and sentinel lymph node biopsy were compared to a combination of histopathology and follow-up. Diagnostic testing was performed using the x2 test.

RESULTS

Histopathological examination revealed metastatic spread to the neck in 14 of 40 patients. One patient had bilateral neck disease. Sentinel lymph node biopsy and ultrasonography were performed in 80 neck sides of 40 patients and MRI in 70 neck sides (5 patients were claustrophobic). SN revealed suspicious lymph nodes in 12 necks, ultrasonography in 23 necks, and MRI in 9 necks. The positive predictive value of sentinel lymph node biopsy was 100%, ultrasonography 57%, and MRI 56%. The respective negative predictive values were 96%, 96%, and 85%. The sensitivity of sentinel lymph node biopsy 80% was comparable to ultrasonography 87%, but the sensitivity of MRI 36% was low. The specificities were 100%, 85%, and 93%, respectively. By combined sentinel lymph node biopsy and ultrasonography the overall sensitivity could have been 100%.

CONCLUSION

Sentinel lymph node biopsy improved staging of patients with small N0 oral cancers. Combined sentinel lymph node biopsy and Doppler ultrasonography may further improve staging. MRI and simple palpation results were poor.

Tumor volume is not an independent prognostic factor in early-stage nasopharyngeal carcinoma treated by radiotherapy alone

PURPOSE

To determine whether the tumor volume can predict the treatment outcome in early-stage nasopharyngeal carcinoma (NPC) treated by radiotherapy alone.

METHODS AND MATERIALS

The pretreatment CT scans of 116 patients with American Joint Committee on Cancer Stage I-II NPC treated by radiotherapy alone were retrospectively reviewed. The clinician outlined the tumor extent. The primary tumor volume (PTV) and nodal volume (NV) were then calculated by a summation-of-areas technique. The PTV and NV were correlated with locoregional control, distant failure, and survival. The median follow-up time was 105 months.

RESULTS

Patients with Stage I disease had a 5-year locoregional control rate of 95% and a disease-specific survival (DSS) rate of 97%; for Stage II disease, the corresponding rates were 81% and 79%. The PTV ranged from 1.3 to 75.5 cm3 (median, 12.6 cm3), with substantial overlap between T1 and T2 disease. The NV ranged from 0 to 35.4 cm(3). Patients with a PTV >15 cm3 had significantly worse local control (5-year control rate, 82% vs. 93%; p = 0.033), but no statistically significant difference was noted in survival (5-year DSS rate, 83% vs. 89%; p = 0.30). The difference in local control was mainly seen in those with T2 disease. Patients with NV >4 cm3 had a greater distant failure rate (5-year distant metastasis-free rate, 72% vs. 90%; p = 0.011) and worse survival (5-year DSS rate, 76% vs. 94%; p = 0.0038). Nodal control was excellent with no difference between a NV of < or =4 cm3 and a NV of >4 cm3 (5-year control rate, 97% vs. 100%). The survival rate was worst in patients with a PTV >15 cm3 and a NV >4 cm3 (5-year DSS rate, 68%) and best in those with a PTV of < or =15 cm3 and a NV of < or =4 cm3 (5-year DSS rate, 92%). Multivariate analysis, however, showed that only parapharyngeal extension (T2b) and N1 stage were independent factors that predicted locoregional control and survival, and N1 stage was the only factor that predicted distant failure.

CONCLUSION

The pretreatment tumor volume has a limited prognostic value in early-stage NPC compared with the usual T and N classification, with Stage T2b and N1 as independent factors that predicted treatment outcome. Within T2 disease, the estimation of tumor volume may identify a subgroup of patients with a greater risk of local failure that warrants more aggressive treatment.

Squamous cell carcinoma of the head and neck in Ontario, Canada, and in southeastern Norway

OBJECTIVES/HYPOTHESIS

Reports comparing case mix, treatments, and outcomes between different countries are uncommon in head and neck oncology. Prospective databases of unselected patients from regional cancer centers in southeastern Ontario, Canada, and southeastern Norway were compared.

STUDY DESIGN

Retrospective comparative study of two prospective databases.

METHODS

The case mix, treatments, and disease-specific mortality were compared using frequency tables, Kaplan-Meier survival curves, and the log rank test. RESULTSThe case mix, except for differences in oral cavity, oropharynx, and the recorded tumor (T) category, was similar, and the treatments were different. There was no statistical difference in overall survival for all patients, as well as for some sites.

CONCLUSIONS

The results of treatments, based on different overall treatment polices, for all patients were similar. The differences in recorded T category with no statistical difference in overall survival suggest a difference in staging assignment and raises a question about the reliability of the TNM staging process.

Prognostic significance of microscopic and macroscopic extracapsular spread from metastatic tumor in the cervical lymph nodes

It has been established that the presence or absence of cervical node metastases in patients with head and neck squamous cell carcinoma (HNSCC) is a powerful prognostic indicator. This report reviews the evolution of thinking over the past 70 years with regard to the import and detection of cervical nodal metastases which exhibit spread of tumor beyond the confines of the original encompassing nodal capsule. In the process, this discussion touches upon clinical examination, gross and microscopic pathologic examination, and radiographic imaging studies. In particular, the distinction between gross nodal extracapsular spread of tumor and microscopic nodal extracapsular spread of tumor has been drawn in recent reports; this raises the possibility that identification of microscopic breaching of the nodc capsule by tumor might provide clinically significant information which is not provided by the gross observation of an intact lymph node capsule. While it remains to be seen whether microscopic extracapsular spread alone will prove to be an important prognostic factor, it is recommended that selective neck dissection continue to be offered even in those patients with clinically negative necks; further studies should aid in defining the import of microscopic extracapsular tumor spread in patients with positive cervical nodes.