Nicholas Hyde

A new approach to pre-treatment assessment of the N0 neck in oral squamous cell carcinoma: the role of sentinel node biopsy and positron emission tomography

OBJECTIVES Pre-operative staging of the clinically N(0) neck in patients with oral squamous cell carcinoma is hindered by the relatively high false negative/positive rates of conventional imaging techniques. The aim of this study is to evaluate the utility of (18)F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) and sentinel lymph node (SLN) imaging and biopsy to determine the true disease status of the loco-regional lymphatics. METHODS Nineteen patients with biopsy proven disease without palpable or radiological evidence of neck metastases underwent pre-operative (18)F-FDG PET and SLN imaging. All patients underwent whole-body FDG PET and a single view of the head and neck. SLN technique was performed using four peri-tumoural injections of (99m)Tc labeled albumin colloid each of 10 MBq. Dynamic and static imaging followed in the antero-posterior and lateral projections. At operation 1 ml of 2.5% Patent Blue Dye and a hand held gamma probe (Neoprobe 1500) were used in combination to identify and remove the SLN. Surgery then continued along conventional lines including a neck dissection. Histology of the resultant specimen was correlated with that of the SLN and pre-operative imaging. RESULTS In all patients SLN harvesting was feasible. In 15/19 patients the SLN(s) and the residual neck dissection were -ve for tumour. In 3/19 patients the SLN(s) were +ve for tumour as were other neck nodes. In 1/19 patients the SLN was -ve but another single tumour +ve node was identified in the neck. This patient occurred early in our series with a SLN close to the primary tumour. (18)F-FDG PET failed to identify nodal disease in all four patients with histologically proven lymph node metastases. The size of these nodes ranged from 12 mm x 10 mm x 3 mm to 25 mm x 15 mm x 10 mm. CONCLUSION SLN imaging and biopsy with probe and Patent Blue Dye guided harvest is feasible in patients with oral squamous cell carcinoma and can predict cervical nodal status. (18)F-FDG PET may be less useful.

Endoscopic removal of a supernumerary tooth from the nasal cavity in an adult.

Eruption of a tooth into the nasal cavity is a rare event. However it is important to identify such a condition as it has the potential to cause significant morbidity. We report a unique case of intranasal supernumerary tooth erupted into nasal causing significant nasal symptoms in an otherwise healthy patient which was removed endoscopically.

Decreased levels of alternative co-stimulatory receptors OX40 and 4-1BB characterise T cells from head and neck cancer patients

BACKGROUND AND AIM Head and neck cancers (HNC) are aggressive tumours. Tumour-specific T cells are frequently identified in patients with cancer, although they fail to control tumour progression. A family of proteins called co-stimulatory receptors regulate the function of T cells and may account for T cell dysfunction in cancer. Our aim was to characterise co-stimulatory receptors on T cells in HNC patients to identify novel targets for immunotherapy. METHODS Peripheral blood mononuclear cells were isolated from HNC patients and healthy controls and the expression of co-stimulatory (OX40, 4-1BB, ICOS) and co-inhibitory (CTLA-4, PD1) receptors was analysed on CD4(+) and CD8(+) T cells using flow cytometry. RESULTS We found that the levels of co-stimulatory receptors OX40 and 4-1BB were significantly lower on CD4(+) T cells from HNC patients. This was more pronounced in locally advanced tumours (T3/T4) compared to early carcinomas (T1/T2). PD-1 levels were higher on CD8(+) T cells in HNC patients compared to controls. Human papilloma virus (HPV)-specific CD8(+) T cells appeared to be more affected than Influenza-specific T cells. CONCLUSIONS Our results indicate that expression of co-stimulatory receptors on T cells from HNC patients is imbalanced with a preponderance of inhibitory signals, and reduction of stimulatory signals, especially in advanced disease. Restoring this balance could improve T cell therapy outcomes in HNC.

Does the method of resection affect the margins of tumours in the oral cavity? Prospective controlled study in pigs

It is important to obtain tumour-free resection margins in patients with oral cancer. Pathological processing is known to cause tissue to shrink, which affects the reported margins, and it is postulated that the method of resection also has an effect. We marked standardised simulated lesions on the tongues of 15 live anaesthetised pigs and divided each lesion into four equal sections. They were resected each with a margin of 10mm using cutting diathermy, coagulative diathermy, Harmonic scalpel, and a conventional scalpel. After processing, the excision margins were measured. With cutting diathermy and coagulative diathermy, shrinkage of the soft tissues was minimal relative to the margin of the simulated lesion compared with the Harmonic scalpel (p=0.001) and conventional scalpel (p=0.001). Cutting diathermy and coagulative diathermy caused significant thermal damage (p=0.001). The method of resection affects the surgical margin. Diathermy resulted in thermal injury and denaturing of the underlying muscle, but there was less tissue contraction than when the Harmonic scalpel and conventional scalpel were used. The ethics committee approved the study, which was undertaken in a registered European Scientific Institute in Hamburg.

Impact of colour digital photography on pathologists' orientation of resected specimens: a prospective pilot study.

Accurate orientation of surgical resection specimens is a prerequisite for the correct histopathological study of the extent of disease and for a complete clinico-pathological interpretation. This pilot study demonstrates how the pathologists understanding of specimen orientation may be enhanced by the sending of a digital image with the pathology request form.

A needle free system for cervical lymphatic mapping and sentinel node biopsy in oral squamous cell carcinoma.

The techniques of lymphatic mapping and sentinel node biopsy are finding increasing utility in the management of the loco-regional lymphatics in many areas of oncology. Our unit is currently investigating their feasibility in relation to the management of the clinically node negative neck in oral squamous cell carcinoma. In order to reduce patient discomfort, and to remove the possibility of sharps injury, particularly in the high-risk patient, we report the use of a needle free device for the intra-oral delivery of the radiopharmaceutical. We believe that this is the first report using such a device in the oral cavity for the purpose of lymphoscintigraphy, and that it has significant advantages over the conventional hypodermic needle in certain patient groups.

Mesiodens: An Unusual Cause of a Facial Sinus

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